JPH0728626U - Curved pipe manufacturing equipment - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to make the structure of a bending pipe made of a synthetic resin bent at about 180 ° simple and compact. [Structure] Left and right straight mold portions 14A, 14B integrally interconnected with an inner mold 13 for molding the inner shape of a curved pipe 10.
And the left and right curved shape portions 15 divided along the division line DL.
It is divided into A and 15B so that it can be pulled out from the inside of the molded curved pipe 10, but the dividing line DL is inclined from the curved center O to the longer straight pipe portion 10A of the curved pipe 10, The effective width of the curved portion 15A of the straight pipe portion 10A is reduced.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an apparatus for manufacturing a curved pipe bent at about 180 °, such as a synthetic resin U-trap.

[0002]

[Prior art]

 As shown in FIG. 5, for example, the U-trap (10), which is a curved pipe bent at about 180 °, has a curved portion interposed between the right and left straight pipe portions (10A, 10B) and the straight pipe portions (10A, 10B). (10C), the straight pipe section (10A) on the inflow side is set longer than the straight pipe section (10B) on the outflow side. Conventionally, an outer mold (2) having a mold surface (2A) shape corresponding to the outer shell shape of the U trap (10) to be molded as shown in FIGS. 6 to 8, and the U trap (10) It consists of an inner mold (3) having a mold surface (3A) shape corresponding to the inner shape, and the inner mold (3) is integrally interconnected to the left and right straight mold parts (4A, 4B) and curved. U trap manufacturing device that is divided into left and right curved mold parts (5A, 5B) that are bisected along the perpendicular line VL from the center O so that it can be extracted from the molded product ( 1) is provided (Japanese Utility Model Publication No. 5-14829). In the above configuration, after the U trap (10) is injection molded, the outer mold (2) is opened and the inner mold (3) is pulled out from the U trap (10) by the operating rods (6A, 6B). , The curved mold part (5A, 5B) of the inner mold (3) is connected to the operating rod (6A, 6B) via the link arm (8A, 8B), so the curved mold part (5A, 5B) As shown in FIG. 7, the operating rods (6A, 6B) are guided by the guide pins (7A, 7B) about the center of curvature O of the U trap (10) and are rotated, and then the straight part (4A , 4B) and is linearly pulled out as shown in FIG.

[0003]

[Problems to be solved by the device]

 However, in the above-mentioned conventional U-trap manufacturing apparatus (1), since the left and right straight pipe portions (10A, 10B) are integrally connected to each other, the driving unit of the inner mold (3) is unified. It can be put together and is rational. However, since the left and right curved parts (5A, 5B) of the inner mold (3) are divided along the perpendicular line VL from the center of curvature O, the curved part (5B) on the outflow side is the U trap (10). Even if it is completely withdrawn from the outflow side straight pipe part (10B), the inflow side curved portion (5A) has not yet been pulled out from the U trap (10) inflow side straight pipe part (10A). First, as shown in FIG. 8, when the curved portion (5A) is completely withdrawn from the straight pipe portion (10A), the curved portion (5B) on the outflow side and the outflow side of the U trap (10). A gap corresponding to the length difference Δl of the straight pipe portions (10A, 10B) is formed between the straight pipe portion (10B) and the straight pipe portion (10B). That is, there is a problem in that the stroke of the curved portion (5B) on the outflow side is pulled out from the U trap (10), and the stroke is lost by Δl. Further, since the lowest trace TR is formed inside the curved pipe 10, there is a problem that the trace TR interferes and dust and mud cannot be easily removed from the pipe.

[0004]

[Means for Solving the Problems]

 As a means for solving the above-mentioned conventional problems, the present invention consists of right and left straight pipe portions (10A, 10B) and a curved portion (10C) interposed between the straight pipe portions (10A, 10B). The straight pipe part (10A) of the outer mold (12A) has a mold surface (12A) shape corresponding to the outer shell shape of the curved pipe (10) which is set longer than the other straight pipe part (10B), The left and right straight mold parts are composed of an inner mold (13) having a mold surface (13A) shape corresponding to the inner shape of the curved pipe (10), and the inner mold (13) is integrally connected to each other. (14A, 14B) and the left and right curved shape parts (15A, 14B) divided in two along a dividing line DL inclined from the curved center O to the longer straight pipe part (10A) of the curved pipe (10). The present invention provides a manufacturing device (11) for a curved pipe (10), which is composed of 15B).

[0005]

[Action]

 In the present invention, the inner mold (13) of the bending pipe (10) manufacturing device (11) is divided into left and right straight mold parts (14A, 14B) and left and right curved mold parts (15A, 15B). Since the left and right straight mold parts (14A, 14B) are integrally connected to each other, it is possible to combine the driving parts of the inner mold (13) into one. Further, the left and right curved portions (15A, 15B) are rotated along the curved portion (10C) of the curved pipe (10) and then linearly straight (10A, 10B) of the curved pipe (10). The left and right curved shape parts (15A, 15B) are divided into two parts along a dividing line DL that is inclined from the center of the curve O to the longer straight pipe part (10A) of the curved pipe (10). Therefore, the effective width of the curved portion (15A) on the longer straight pipe portion (10A) side is smaller than the effective width of the curved portion (15B) on the shorter straight pipe portion (10B) side. The pull stroke of the curved portion (15A) is shortened accordingly. Then, the straight pipe portion (10A, 10B) of the curved pipe (10) in which the curved die portion (15A, 15B) of the inner die (13) is formed by setting the inclination angle α of the dividing line DL to a predetermined value It is possible to pull out from the same time. And, in such a dividing manner of the inner mold (13), no mold mark is formed at the lowest portion of the curved pipe molded.

[0006]

【Example】

 The present invention will be described with reference to an embodiment shown in FIGS. 1 to 5. An apparatus (11) for manufacturing a U-trap (10), which is a curved tube shown in the drawings, by injection molding is a U-trap to be formed. An outer mold (12) having a mold surface (12A) shape corresponding to the outer shell shape of (10), and an inner mold (13A) having a mold surface (13A) shape corresponding to the inner shape of the U trap (10). ), The outer mold (12) can be opened and closed in the front-rear direction, and the inner mold (13) is integrally connected to each other. From the right and left straight mold parts (14A, 14B) and the center of curvature O. The U trap (10) is composed of right and left curved parts (15A, 15B) which are divided into two parts along a dividing line DL inclined from the longer straight pipe part (10A). The actuating rods (16A, 16B) for pulling out are respectively passed through the direct mold parts (14A, 14B) of the inner mold (13), and the curved mold parts (15A, 15B) are respectively linked arm (18A). , 18B) and is connected to the operating rods (16A, 16B). Further, the guide holes (14C, 14D) of the straight mold parts (14A, 14B) are penetrated by guide pins (17A, 17B), and the tips of the guide pins (17A, 17B) are bent at the curved mold parts (15A , 15B) are inserted into the guide holes (15C, 15D).

In the above-mentioned structure, polyvinyl chloride, polyethylene, in a cavity formed between the outer mold (12) and the inner mold (13) in a closed state of the manufacturing apparatus (11) shown in FIG. A thermoplastic such as polypropylene is injected to mold the U-trap (10). After molding, the straight mold parts (14A, 14B) are pulled out by a predetermined stroke by a driving part (not shown), and the bending rod parts (15A, 15B) are pulled upward by pulling the actuating rods (16A, 16B) upwards. 17B) as a guide, as shown in FIG. 2, it rotates around the curved center O along the curved portion (10C) of the U trap (10), and then is pulled out straight upward as shown in FIG. Get burned.

FIG. 4 shows details of the curved parts (15A, 15B) of the inner mold (13) of the device (11). As described above, the curved portions (15A, 15B) move from the closed state shown by the solid line to the state of being rotated around the bending center O shown by the chain double-dashed line, and then linearly pulled upward. Assuming that the central angle of the curved portion (15B) is 2θ ° and the inclination angle of the dividing line DL with respect to the perpendicular line VL from the center O is α °, the curved portion (15B) may be O in the two-dot chain line state. Their horizontal line HL bisects the curved portion (15B). Therefore, since the angle formed by VL and HL is 90 °, there is a relation of θ + (2θ−α) = 90, that is, θ = (90 + α) / 3, with α ° of θ °.

Further, when the curved shape portions (15A, 15B) are rotated by 2θ ° and the lower lengths l ₁ and l ₂ are obtained from HL, from the center O to the outer contour of the curved shape portions (15A, 15B). Assuming that the radius of R is R, l ₁ = R s in θ and l ₂ = R sin (θ−2α).

To minimize the drawing stroke, l ₁ −l ₂ = l (where l is the difference in length of the straight pipe portions (10A, 10B) of the U trap (10)) Good. That is, l = R [sin θ−sin (θ−2α)]. That is, when designing the inner mold (13), if θ ° and α ° satisfying the following conditions are obtained, the drawing stroke of the inner mold (13) can be minimized, that is, the stroke loss can be substantially zero. I can. θ = (90 + α) / 3 l = R [sin θ-sin (θ-2α)] Under these conditions, the curved part (15A, 15B) of the inner mold (13) is a straight pipe part of the molded U-trap (10). It will be pulled out from (10A, 10B) at the same time.

The U trap (10) thus formed as shown in FIG. 3 is used to form the straight mold part (14A) and the straight mold part (14B) of the inner mold (13) and the curved mold parts (15A, 15B). Are completely pulled out, the outer mold (12) is opened, and the U trap (10) is taken out from the manufacturing apparatus (11). Since the inner mold (13) is not divided at the innermost lowest position of the U trap (10), there is no mark.

[0012]

[Effect of device]

 Therefore, the present invention provides an apparatus for manufacturing a flexible tube having a compact structure in which the drawing stroke of the inner die is shortened.

[Brief description of drawings]

 1 to 5 show an embodiment of the present invention.

FIG. 1 is a sectional view of a mold-closed state manufacturing apparatus.

FIG. 2 is a sectional view of a manufacturing apparatus in an inner die drawing process.

FIG. 3 is a sectional view of the manufacturing apparatus in a state where the inner mold is completely pulled out.

FIG. 4 is an explanatory diagram of an inner curved portion.

FIG. 5 is a perspective view of a U-trap (curved tube). FIGS. 6 to 8 show a conventional example.

FIG. 6 is a cross-sectional view of the manufacturing apparatus in a mold closed state.

FIG. 7 is a sectional view of the manufacturing apparatus in the process of pulling out the inner mold.

FIG. 8 is a sectional view of the manufacturing apparatus in a state where the inner mold is completely pulled out.

[Explanation of symbols]

 10 Curved tube 10A, 10B Straight tube section 10C Curved section 11 Curved tube manufacturing equipment 12 Outer mold 12A Mold surface 13 Inner mold 13A Mold surface 14A, 14B Straight mold section 15A, 15B Curved mold section DL Split line

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[Procedure amendment]

[Submission date] December 28, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 2

[Correction method] Change

[Correction content]

[Fig. 2]

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 3

[Correction method] Change

[Correction content]

[Figure 3]

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. Right and left straight pipe portions, and curved portions interposed between the straight pipe portions, one straight pipe portion being set to be longer than the other straight pipe portion in the outer shell shape of the curved pipe. It consists of an outer mold having a corresponding mold surface shape and an inner mold having a mold surface shape corresponding to the inner shape of the curved pipe, the inner mold being curved integrally with the left and right straight mold portions and the curved shape. An apparatus for manufacturing a curved pipe, characterized in that the curved pipe is composed of two left and right curved parts that are divided into two along a dividing line that is inclined from the center of the long straight pipe part of the curved pipe.