JP7478956B2 - Manufacturing method of the water sprinkler plate - Google Patents

Description

The present invention relates to a method for manufacturing a water sprinkler plate.

A conventional spray plate is known, for example, from the one described in Patent Document 1. The spray plate disclosed in Patent Document 1 is a spray plate for a shower device, and has a spray surface that is rectangular in plan view and has a predetermined width and length, and a number of spray holes formed through the spray surface. The spray direction of each of the spray holes is directed outward in the width direction as it moves from the inside to the outside of the spray surface. This configuration produces a shower water discharge that spreads outward from the spray surface.

JP 2016-2243 A

When a sprinkler plate such as that disclosed in Patent Document 1 is manufactured by resin molding, weld lines that form at the ends of the sprinkler holes can cause the water discharge direction to vary, or water can be discharged in a direction different from the desired direction. There is room for improvement in terms of achieving the desired water discharge shape.

The object of the present invention is therefore to provide a method for manufacturing a water sprinkler plate that can achieve the desired water discharge shape by solving the above problems.

In order to achieve the above object, the method of manufacturing a water spray plate of the present invention is a method of manufacturing a water spray plate having a main body portion formed with a plurality of through holes for shower water discharge penetrating from the water spray surface in the thickness direction and a separate water discharge opening at the center, and a cylindrical portion protruding in a cylindrical shape from the back surface of the main body portion so as to extend the opening to the opposite side of the water spray surface, by resin molding in which a pair of dies are filled with resin and the dies are removed along the thickness direction, the method comprising the steps of preparing a pair of dies having a cavity for filling resin and a gate formed therein as an inlet to the cavity, the cavity being formed by inserting the resin into the main body portion and the gate into the cavity, the method comprising the steps of: The method includes the steps of: a first space having a shape corresponding to the cylindrical portion, and a second space connected to the first space and having a shape corresponding to the cylindrical portion, and the gate has a third space extending in a direction intersecting the attachment/detachment direction of the mold so as to connect the inner periphery of the first space of the cavity at a predetermined position; filling the resin from the third space of the gate into the first space and the second space of the cavity; separating the pair of molds in the attachment/detachment direction; and removing the resin filled in the third space and leaving the resin filled in the first space and the second space as the water sprinkler plate.

The manufacturing method of the water sprinkler plate of the present invention makes it possible to achieve the desired water discharge shape.

FIG. 1 is a schematic perspective view of a water spray plate and a shower head including the water spray plate according to an embodiment; FIG. 1 is a perspective view of the front surface side of a water sprinkler plate according to an embodiment; FIG. 1 is a perspective view of the rear side of a water sprinkler plate according to an embodiment; FIG. 3 is a plan view of the front surface side of the water sprinkler plate in the embodiment; FIG. 1 is a plan view of the rear side of a water sprinkler plate according to an embodiment; Partially enlarged view of FIG. FIG. 6 is a perspective view showing a cross section of the water sprinkler plate shown in FIG. 5 at a predetermined position. FIG. 4 and FIG. 5 are enlarged views of part I. 8. A view of the first through hole taken along the line K-K in FIG. 10 is a view of the second through hole as seen along the arrows L-L in FIG. 8 . 8. A view of the third through hole as seen from the arrow M-M in FIG. An image of the water discharge form by the water spray plate in the embodiment. FIG. 1 is a vertical cross-sectional view showing a schematic configuration of a water sprinkler plate according to an embodiment. FIG. 12 is a vertical cross-sectional view showing a schematic configuration of a mold for resin molding the water sprinkler plate shown in FIG. FIG. 12 is a vertical cross-sectional view showing a schematic configuration of a mold for resin molding the water sprinkler plate shown in FIG. A flowchart showing an example of a method for resin-molding a sprinkler plate using the pair of molds shown in FIG. 12A and FIG. 12B. FIG. 14 is an explanatory diagram for executing each step according to the flowchart of FIG. 13. FIG. 14 is an explanatory diagram for executing each step according to the flowchart of FIG. 13. FIG. 14 is an explanatory diagram for executing each step according to the flowchart of FIG. 13. FIG. 14 is an explanatory diagram for executing each step according to the flowchart of FIG. 13. FIG. 14 is an explanatory diagram for executing each step according to the flowchart of FIG. 13. FIG. 14 is an explanatory diagram for executing each step according to the flowchart of FIG. 13. FIG. 14 is an explanatory diagram for executing each step according to the flowchart of FIG. 13. FIG. 14 is an explanatory diagram for executing each step according to the flowchart of FIG. 13. FIG. 14 is an explanatory diagram for executing each step according to the flowchart of FIG. 13. FIG. 14 is an explanatory diagram for executing each step according to the flowchart of FIG. 13.

Below, an embodiment of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to this embodiment.

(Embodiment)
FIG. 1 is a schematic perspective view of a spray plate and a showerhead including the spray plate according to an embodiment.

The shower head 2 shown in Figure 1 is a shower head used in bathrooms, washrooms, kitchens, etc. As shown in Figure 1, the shower head 2 includes a head body 4 and a water spray plate 6.

The head body 4 is the part that constitutes the main body of the shower head 2 and contains a shower hose (not shown).

The water spray plate 6 is a member attached to the tip of the head body 4, and sprays water supplied from the head body 4. A number of openings for spraying water are formed on the surface of the water spray plate 6, and the water spray plate 6 of this embodiment sprays water in two ways: shower water spray S1 and straight water spray S2.

The schematic configuration of the water sprinkler plate 6 will be described with reference to Figures 2 and 3. Figure 2 is a perspective view of the front side of the water sprinkler plate 6, and Figure 3 is a perspective view of the back side of the water sprinkler plate 6.

As shown in Figures 2 and 3, the water spray plate 6 has a main body 8, an inner first cylindrical portion 10, and an outer second cylindrical portion 12.

The main body 8 is a part that constitutes the main body of the water spray plate 6, and has a constant thickness along the thickness direction T. The main body 8 has a plurality of through-hole groups 81, 82, 83 that penetrate in the thickness direction T. The through-hole groups 81, 82, 83 are holes for the shower water discharge S1 described above. An opening 14 is also formed in the center of the main body 8 for straight water discharge S2.

The main body 8 has a water spray surface 85 (Fig. 2) on the front side and a back surface 220 (Fig. 3) on the back side. Both the water spray surface 85 and the back surface 220 have an annular shape in a plan view. Each of the through holes constituting the through hole groups 81, 82, 83 penetrates in the thickness direction T from the water spray surface 85 to the back surface 220. The "through holes" may also be referred to as "water spray holes", and the "water spray surface" may also be referred to as the "water discharge surface" or the "outflow surface".

The first cylindrical portion 10 and the second cylindrical portion 12 are both cylindrically protruding portions from the back surface 220 of the main body portion 8 to the rear side. The first cylindrical portion 10 and the second cylindrical portion 12 are flow path forming portions that form a flow path, and are also mounting portions for mounting the sprinkler plate 6 to the head main body portion 4 shown in FIG. 1. The first cylindrical portion 10 has a shape that causes the inner edge of the main body portion 8 that forms the opening 14 to extend cylindrically toward the rear side opposite the sprinkler surface 85. The second cylindrical portion 12 has a shape that causes the outer edge of the main body portion 8 to extend cylindrically toward the rear side opposite the sprinkler surface 85.

The configuration of the water sprinkler hole groups 81, 82, and 83 will be described with reference to Figures 4 to 9C. Figure 4 is a plan view of the front side of the water sprinkler plate 6, and Figure 5 is a perspective view of the back side of the water sprinkler plate 6.

As shown in Figures 4 and 5, the first through-hole group 81 is made up of a plurality of through-holes arranged in the outermost circle. Similarly, the second through-hole group 82 is made up of a plurality of through-holes arranged in the center circle, and the third through-hole group 83 is made up of a plurality of through-holes arranged in the innermost circle.

In this embodiment, each of the through holes constituting the first through hole group 81, the second through hole group 82, and the third through hole group 83 is circular in plan view. The number of through holes constituting each of the first through hole group 81, the second through hole group 82, and the third through hole group 83 is the same. The through holes of the first through hole group 81, the second through hole group 82, and the third through hole group 83 are arranged in a row along the radial direction H of the water sprinkler plate 6.

As shown in FIG. 5, when the rear surface 220 is viewed in plan, each of the through holes constituting the first through hole group 81, the second through hole group 82, and the third through hole group 83 has an opening shape that is different from a circular shape. In this embodiment, the opening shape of each through hole on the rear surface 220 is an elongated hole shape, and is provided at a uniform inclination with respect to the radial direction H.

Figure 6 shows an enlarged view of a portion of Figure 5, Figure 7 shows a perspective view of a cross section at a specific position of the water spray plate 6 shown in Figure 5, and Figure 8 shows an enlarged view of part I in Figures 4 and 5.

As shown in Figures 6 and 7, the through holes constituting the first through hole group 81, the second through hole group 82, and the third through hole group 83 have an elongated hole-shaped upstream opening and a circular downstream opening. Each through hole has a tapered shape that narrows from upstream to downstream. The elongated hole shape is a combination of an arc shape and a linear shape. When the rear surface 220 is viewed in plan as shown in Figure 6, the elongated hole shape on the upstream side of each through hole encompasses the entire circular shape on the downstream side.

As shown in FIG. 8, the first through holes (first sprinkler holes) 81J constituting the first through hole group 81 are arranged on a circumference 92 and form a downstream opening 86A which is an opening at the downstream end and an upstream opening 86B which is an opening at the upstream end. The downstream opening 86A is a circular opening that opens at the sprinkler surface 85, and the upstream opening 86B is an elongated opening that opens at the back surface 220. Water passing through the first through hole 81J flows along a center line 87 from the upstream opening 86B to the downstream opening 86A. The center line 87 is a line that connects the opening center of the upstream opening 86B and the opening center of the downstream opening 86A, and approximately coincides with the water discharge direction of the first through hole 81J.

Similarly, the second through holes (second sprinkler holes) 82J constituting the second through hole group 82 are arranged on the circumference 93 and form a downstream opening 88A which is an opening at the downstream end and an upstream opening 88B which is an opening at the upstream end. Water passing through the second through hole 82J flows along the center line 89 from the upstream opening 88B to the downstream opening 88A.

Similarly, the third through holes (third sprinkler holes) 83J constituting the third through hole group 83 are arranged on the circumference 94 and form a downstream opening 90A which is an opening at the downstream end and an upstream opening 90B which is an opening at the upstream end. Water passing through the third through hole 83J flows along the center line 91 from the upstream opening 90B to the downstream opening 90A.

The center lines 87, 89, 91 corresponding to the discharge directions of the first through hole 81J, the second through hole 82J, and the third through hole 83J all include inclination components α1, α2, α3 with respect to the normal directions U1, U2, U3 of the respective circumferences 92, 93, 94. In particular, in this embodiment, the center lines 87, 89, 91 all face toward the center with respect to the tangential directions of the respective circumferences 92, 93, 94. Furthermore, in this embodiment, the shapes of the respective through holes 81J, 82J, 83J are set so that the relationship α1>α2>α3 is satisfied.

Figures 9A, 9B, and 9C show longitudinal cross-sectional views of the first through hole 81J, the second through hole 82J, and the third through hole 83J. Figure 9A is a view taken along the arrows K-K of the first through hole 81J in Figure 8, Figure 9B is a view taken along the arrows L-L of the second through hole 82J in Figure 8, and Figure 9C is a view taken along the arrows M-M of the third through hole 83J in Figure 8.

As shown in FIG. 9A, the center line 87 of the first through hole 81J, which corresponds to the water ejection direction, has an inclination component β1 with respect to the thickness direction T of the water spray plate 6. Similarly, as shown in FIG. 9B, the center line 89 of the second through hole 82J has an inclination component β2 with respect to the thickness direction T, and as shown in FIG. 9C, the center line 91 of the third through hole 83J has an inclination component β3 with respect to the thickness direction T. All of the inclination components β1, β2, and β3 are components that point toward the center of the water spray surface 85, as shown in FIG. 8.

In particular, in embodiment 3, the shapes of the through holes 81J, 82J, and 83J are set so that the relationship β1>β2>β3 is satisfied.

The above-mentioned configuration of the through holes 81J, 82J, and 83J can create a triple spiral flow as shown in FIG. 10. In FIG. 10, the water spray plate 6 is shown in a simplified form. As shown in FIG. 10, the more outer the through hole group 81, 82, and 83, the stronger the component of the flow that is oriented horizontally, which is parallel to the water spray surface 85. Since the water discharged from the through hole groups 81, 82, and 83 all falls toward the center, it converges once in the converging region 96, and then diverges from the diverging region 98 in a direction away from the center. When the water diverges in the diverging region 98, the more outer the through hole group 81, 82, and 83, the more it diverges in a direction away from the center.

This type of water discharge shape is not just aesthetically pleasing, but also makes it possible to use areas where water hits with a large contact area, such as the converging area 96, and areas where water hits with a small contact area, such as the diverging area 98, depending on the purpose of use.

In this embodiment, the water sprinkler plate 6 having the above-described configuration is manufactured by resin molding. An example of a specific manufacturing method will be described with reference to Figures 11 to 14J.

Figure 11 is a vertical cross-sectional view showing the schematic configuration of the sprinkler plate 6. In Figure 11, the same components as those in the sprinkler plate 6 shown in Figures 1 to 10 are given the same reference numerals, and the sprinkler plate 6 is illustrated in a simplified manner. Similarly, in Figures 11 and onwards, the sprinkler plate 6 and the mold 20 corresponding to the sprinkler plate 6 are illustrated in a simplified manner.

Figures 12A and 12B are vertical cross-sectional views showing the schematic configuration of a pair of molds 20 for resin molding the sprinkler plate 6 shown in Figure 11.

As shown in Figures 12A and 12B, the pair of molds 20 includes a first mold 22 and a second mold 24. Figure 12A shows the first mold 22 and the second mold 24 aligned in the attachment/detachment direction L, and Figure 12B shows the first mold 22 and the second mold 24 separated in the removal direction L. The attachment/detachment direction L corresponds to the thickness direction T of the water sprinkler plate 6 shown in Figure 11.

As shown in Figures 12A and 12B, the first mold 22 forms a runner 26 inside. The runner 26 is a space that is connected to a gate 27 formed in the second mold 24.

The second mold 24 has a gate 27, a cavity 28, and an air vent 29 formed therein.

The gate 27 is a space that serves as an inlet for resin to flow into the cavity 28. In this embodiment, the gate 27 extends in an end face direction M that intersects with the attachment/detachment direction L. The end face direction M is the direction in which the end face 30 of the first mold 22 and the end face 31 of the second mold 24 extend, and in this embodiment, is perpendicular to the attachment/detachment direction L. As shown in FIG. 12A, when the first mold 22 and the second mold 24 are aligned in the attachment/detachment direction L, the end face 30 of the first mold 22 and the end face 31 of the second mold 24 come into contact with each other. In FIGS. 12A and 12B, the end faces 30 and 31 are both illustrated as flat surfaces, but may have irregularities or the like.

Cavity 28 is a space having a shape corresponding to the water spray plate 6 shown in FIG. 11. In this embodiment, cavity 28 has space 32, space 34, and space 36.

Space 32 is a space having a shape corresponding to the main body portion 8. Similarly, space 34 is a space having a shape corresponding to the first cylindrical portion 10, and space 36 is a space having a shape corresponding to the second cylindrical portion 12.

A plurality of rod-shaped portions 41, 42, 43 are provided in the space 32. Each of the rod-shaped portions 41, 42, 43 has a shape corresponding to each of the through holes of the water spray hole groups 81, 82, 83 formed by the main body portion 8. The tips of the rod-shaped portions 41, 42, 43 are located flush with the end face 31 of the second mold 24 described above, and contact the end face 30 of the first mold 22 when the first mold 22 and the second mold 24 are joined together as shown in FIG. 12A.

The space 32 has a constant thickness in the attachment/detachment direction L and is roughly annular in shape. The gate 27 extends so as to connect the inner periphery of the space 32 at a predetermined position.

Space 34 and space 36 are each connected to space 32. Space 34 and space 36 each have a cylindrical shape, with space 34 extending cylindrically from the inner edge of space 32 in the attachment/detachment direction L, and space 36 extending cylindrically from the outer edge of space 32 in the attachment/detachment direction L. An air vent 29 is connected to the end of space 36.

Figure 13 shows a flowchart of an example of a method for resin-molding the sprinkler plate 6 using a pair of molds 20 having the above-mentioned configuration. Figures 14A to 14J show various explanatory diagrams for carrying out each step according to the flowchart in Figure 13.

As shown in FIG. 13, first, a pair of molds 20 are prepared (S1). Specifically, as shown in FIG. 14A, a pair of molds 20 shown in FIG. 12A and FIG. 12B are prepared. Furthermore, as shown in FIG. 14B, the first mold 22 and the second mold 24 are brought closer to each other in the attachment/detachment direction L, and the end face 30 of the first mold 22 and the end face 31 of the second mold 24 are brought into contact with each other. At this time, the tip of the runner 26 of the first mold 22 connects to the gate 27 of the second mold 24.

Furthermore, resin is filled into the mold 20 (S2). Specifically, as shown in FIG. 14C, resin 50 is filled into the runner 26 of the first mold 22 (see arrow A1). The resin 50 is, for example, a thermoplastic resin or a thermosetting resin, and is flowed into the runner 26 in a fluid state.

The resin 50 that flows into the runner 26 flows into the gate 27 of the second mold 24, as shown in FIG. 14D. The resin 50 that flows into the gate 27 flows into the spaces 34 and 36 via the space 32, as shown in FIG. 14E. The resin 50 eventually flows into the air vent 29.

Furthermore, the resin 50 is hardened (S3). Specifically, as shown in FIG. 14E, the resin 50 is filled into the cavity 28, and then the resin 50 is hardened by heating in the case of a thermosetting resin, or by cooling in the case of a thermoplastic resin.

Then, the mold 20 is separated (S4). Specifically, as shown in FIG. 14F, the first mold 22 and the second mold 24 are separated in the attachment/detachment direction L.

Then, the temporary molded product 44 is removed from the cavity 28 (S5). Specifically, as shown in FIG. 14F, the temporary molded product 44 made of the cured resin 50 arranged in the second mold 24 is removed in a removal direction L1. This results in a temporary molded product 44 having a thickness along the thickness direction T, as shown in FIG. 14G.

The provisionally molded product 44 shown in FIG. 14G has a shape corresponding to the sprinkler plate 6, and includes a main body 8, a first cylindrical portion 10, and a second cylindrical portion 12. The main body 8 is a resin portion that has hardened in the space 32, the first cylindrical portion 10 is a resin portion that has hardened in the space 34, and the second cylindrical portion 12 is a resin portion that has hardened in the space 36.

The main body 8 has a constant thickness along the thickness direction T, a water spray surface 85 and a back surface 220, and forms through-hole groups 81, 82, and 83 that penetrate from the water spray surface 85 to the back surface 220 in the thickness direction T. Each through-hole of the through-hole groups 81, 82, and 83 has a shape corresponding to the rod-shaped portions 41, 42, and 43 described above.

The temporary molded product 44 further has resin portions 46 and 48. The resin portion 46 is a resin portion that has hardened at the air vent 29, and the resin portion 48 is a resin portion that has hardened at the gate 27.

Furthermore, the resin portion 46 filled in the air vent 29 is removed (S6). Specifically, the resin portion 46 in the temporary molded product 44 shown in FIG. 14G is removed from the temporary molded product 44 using a predetermined tool (not shown) or the like (see arrow A2).

Furthermore, gate cutting is performed (S7). Specifically, similar to step S6, a predetermined tool (not shown) or the like is used to remove the resin portion 48 in the temporary molded product 44 shown in FIG. 14G from the temporary molded product 44 (see arrow A3). This allows the sprinkler plate 6 shown in FIG. 14H to be manufactured as a molded product.

The state before and after gate cutting in step S7 is shown in Figures 14I and 14J. Figure 14I is a perspective view of the temporary molded product 44 before the gate is cut, and Figure 14J is a perspective view of the water sprinkler plate 6 after the gate is cut.

As shown in Figure 14I, in the temporary molded product 44, the water spray surface 85 of the main body 8 and the resin portion 48 are configured to be flush (the boundary between the water spray surface 85 and the resin portion 48 is shown by a dotted line in Figure 14I). As shown by arrow A3, the resin portion 48 is hollowed out using a specified tool to form the water spray plate 6 as shown in Figure 14J. The water spray plate 6 has an opening 14 for straight water discharge in its center, and the first cylindrical portion 10 is exposed so as to define the opening 14.

As described above, when the water spray plate 6 is manufactured by resin molding, weld lines occur at both ends of each of the through holes that make up the through hole groups 81, 82, and 83. Specifically, in Figures 9A to 9C, weld lines occur at the upper and lower ends of the inner edge of the main body 8 that makes up the through holes 81J, 82J, and 83J. In particular, the weld lines of each through hole on the water spray surface 85 (weld lines that occur at the lower end of the inner edge of the main body 8 in Figures 9A to 9C) are likely to affect the water spray direction, and depending on the size of the weld line, the water spray direction may vary from one through hole to another, or water may be sprayed in a direction different from the desired water spray direction.

In contrast, according to the manufacturing method of the present embodiment described above, as shown in Figures 12A and 12B, the gate 27, which is the inlet to the cavity 28, is connected to the space 32 corresponding to the main body portion 8. With this configuration, the position of the gate 27 can be closer to the location where the weld line occurs, as described above, compared to when the gate 27 is connected to the space 34 corresponding to the first cylindrical portion 10. This makes it possible to reduce the weld lines that occur at the ends of each through hole on the water spray surface 85, and to reduce the effect of the weld lines on the water spray direction. In this way, the desired water spray shape can be achieved.

In particular, in this embodiment, the gate 27 extends flush with the end face 31 of the second mold 24 and the end face 30 of the first mold 22, which correspond to the water spray surface 85. This allows the position of the gate 27 to be closer to the location where the weld line occurs, and reduces the effect of the weld line on the water discharge direction.

As shown in Figures 8 and 9A to 9C, the water spray plate 6 of this embodiment sprays water from each spray hole in a direction inclined with respect to the thickness direction T. A water spray plate 6 that performs this type of "oblique water spray" is easily affected by the water spray direction due to weld lines. In this configuration, by devising the connection position of the gate 27 described above, the weld line suppression effect can be more effectively achieved.

As described above, the manufacturing method of the sprinkler plate 6 of the embodiment is a method of manufacturing the sprinkler plate 6 having the main body portion 8 and the first cylindrical portion 10 by resin molding, in which the pair of molds 20 are filled with resin 50 and the molds 20 are removed along the thickness direction T. The main body portion 8 is formed with a plurality of through holes 81J, 82J, 83J for shower water discharge formed by penetrating the sprinkler surface 85 in the thickness direction T, and is formed with an opening 14 for another water discharge at the center. The first cylindrical portion 10 protrudes in a cylindrical shape from the back surface 220 of the main body portion 8 so that the opening 14 extends to the opposite side of the sprinkler surface 85. This manufacturing method includes a step of preparing a pair of molds 20 in which a cavity 28 for filling with resin 50 and a gate 27 that is an inlet to the cavity 28 are formed inside (S1). The cavity 28 has a space 32 (first space) having a shape corresponding to the main body portion 8, and a space 34 (second space) connected to the space 32 and having a shape corresponding to the first cylindrical portion 10. The gate 27 has a space (third space) that extends in an end surface direction M that intersects with the attachment/detachment direction L of the mold 20 so as to connect the inner periphery of the space 32 of the cavity 28 at a predetermined position. This manufacturing method further includes a step of filling the space 32 and the spaces 34, 36 of the cavity 28 with resin 50 from the gate 27 (S2). This manufacturing method further includes a step of separating the pair of molds 20 in the attachment/detachment direction L (S4). This manufacturing method further includes a step of removing the resin 50 filled in the gate 27 and leaving the resin filled in the spaces 32, 34, 36 as the water sprinkler plate 6 (S5 to S7).

According to this method, by connecting the gate 27 to the space 32 corresponding to the main body portion 8, the gate 27 can be placed closer to the location where the weld line occurs, and the size of the weld line can be reduced, compared to when the gate 27 is connected to the space 34 corresponding to the first cylindrical portion 10. This reduces the effect of the weld line on the water discharge direction, and allows the desired water discharge form to be achieved.

In addition, in the embodiment of the water spray plate 6, the gate 27 extends flush with the end faces 30, 31, which are the faces of the space 32 opposite the side connected to the space 34. With this method, the gate 27 can be placed even closer to the location where the weld line occurs, and the effect of the weld line on the water discharge direction can be further reduced.

In addition, in the embodiment of the spray plate 6, the spray holes 81J, 82J, and 83J extend at an angle relative to the thickness direction T. With this method, when water is sprayed obliquely from the spray surface 85, the spray surface 85 is susceptible to the influence of weld lines that occur on the spray surface 85 side, but by making the weld lines smaller, the influence can be effectively reduced.

In addition, in the embodiment of the water spray plate 6, a plurality of water spray holes 81J, 82J, 83J are arranged circumferentially at intervals on the water spray surface 85 of the water spray plate 6. The direction in which the center lines 87, 89, 91 connecting the center of the opening at the upstream end and the center of the opening at the downstream end of each of the plurality of water spray holes 81J, 82J, 83J extend includes inclination components α1, α2, α3 with respect to the normal directions U1, U2, U3 of the circumference of each water spray hole 81J, 82J, 83J when the water spray surface 85 is viewed in a plane. According to this method, when water is sprayed obliquely from the water spray surface 85, the influence of the weld line that occurs on the water spray surface 85 side is easily noticeable, but by making the weld line smaller, the influence can be effectively reduced.

The present invention is not limited to the above embodiment, and can be embodied in various other forms. For example, in the embodiment, as shown in FIG. 8, the center lines 87, 89, 91 of the watering holes 81J, 82J, 83J extend from the upstream side to the downstream side toward the center rather than the tangent direction of each circumference 92, 93, 94. However, the present invention is not limited to this case. For example, the center lines 87, 89, 91 may be oriented in a direction away from the center rather than the tangent direction of each circumference 92, 93, 94.

In the embodiment, the slope component α1 shown in FIG. 8 and the slope component β1 shown in FIG. 9A are common to through-hole group 81, the slope component α2 and the slope component β2 shown in FIG. 9B are common to through-hole group 82, and the slope component α3 and the slope component β3 shown in FIG. 9C are common to through-hole group 83. However, this is not the only case. The slope component may be different for each watering hole in each through-hole group.

In the embodiment, three groups of water sprinkler holes, 81, 82, and 83, are provided, but the present invention is not limited to this case, and any number of groups of water sprinkler holes may be provided.

In the embodiment, a case where a mold 20 having a shape as shown in Fig. 12A and Fig. 12B is used has been described, but the present invention is not limited to such a case. A mold of any shape may be used as long as it is capable of performing the steps of the flowchart shown in Fig. 13 and resin-molding a sprinkler plate 6 having a shape as shown in Fig. 14H.

The various forms described above can be combined as appropriate to achieve the effects of each.

Although the present invention has been fully described in connection with the preferred embodiment with reference to the accompanying drawings, various changes and modifications will be apparent to those skilled in the art. Such changes and modifications are to be understood as being included within the scope of the present invention as defined by the appended claims, unless they deviate therefrom. Also, changes in the combination and order of elements in the embodiments may be made without departing from the scope and spirit of the present invention.

The present invention is useful for any type of spray plate used in a shower head.

2 shower head 4 head main body 6 water spray plate 8 main body 10 first cylindrical portion 12 second cylindrical portion 14 opening 20 mold 22 first mold 24 second mold 26 runner 27 gate (third space)
28 Cavity 29 Air vent 30 End surface 32 Space (first space)
34 Space (Second Space)
36 Spaces 41, 42, 43 Rod-shaped portion 81 First through-hole group 81J First through-hole (first water sprinkler hole)
82 Second through-hole group 82J Second through-hole (second water sprinkler hole)
83 Third through-hole group 83J Third through-hole (third water sprinkler hole)
85 Water spray surface 86A Downstream opening 86B Upstream opening 87 Discharge direction (center line)
88A Downstream opening 88B Upstream opening 89 Discharge direction (center line)
90A Downstream opening 90B Upstream opening 91 Discharge direction (center line)
92, 93, 94 Circumference 96 Converging region 98 Diverging region 220 Back surface L Attachment/detachment direction L1 Removal direction M End surface direction T Thickness direction S1 Shower water discharge S2 Straight water discharge U1, U2, U3 Normal direction X, X1, X2, X3 Horizontal dimension α1, α2, α3 Inclination component with respect to the normal direction β1, β2, β3 Inclination component with respect to the thickness direction

Claims (4)

A method for manufacturing a spray plate having a main body portion in which a plurality of through holes for shower water discharge are formed by penetrating the spray surface in the thickness direction and formed around an opening portion for another water discharge, and a cylindrical portion protruding in a cylindrical shape from the back surface of the main body portion so as to extend the opening portion to the opposite side of the spray surface, by resin molding in which a pair of dies are filled with resin and the dies are removed along the thickness direction,
a step of preparing a pair of molds each having a cavity for filling resin and a gate formed therein as an inlet to the cavity, the cavity having a first space having a shape corresponding to the main body portion, and a second space connected to the first space and having a shape corresponding to the cylindrical portion, and the gate having a third space extending in a direction intersecting a direction in which the molds are attached and detached so as to connect an inner periphery of the first space of the cavity at a predetermined position;
filling the resin from the third space of the gate into the first space and the second space of the cavity;
separating the pair of dies in the attachment/detachment direction;
removing the resin filled in the third space and leaving the resin filled in the first space and the second space as the sprinkler plate. The method for manufacturing a water sprinkler plate according to claim 1, wherein the third space extends flush with the end face of the first space opposite the end connected to the second space. The method for manufacturing a sprinkler plate according to claim 1 or 2, wherein the through holes extend at an angle with respect to the thickness direction. The plurality of through holes are arranged circumferentially at intervals on the water spray surface of the water spray plate,
A method for manufacturing a sprinkler plate as described in any one of claims 1 to 3, wherein the direction in which a center line connecting the center of the opening at the upstream end and the center of the opening at the downstream end of each of the multiple through holes extends includes an inclined component with respect to the normal direction of the circumference at each through hole when the sprinkler surface is viewed in a plane.

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