JP6850110B2 - Valve body molding method for soft seal sluice valve - Google Patents

Description

The present invention relates to a valve body forming method for a soft-sealed sluice valve lined with an elastic material, and more particularly to a valve body forming method suitable for a full-lined soft-sealed sluice valve in which the entire surface of a valve body core material is lined. ..

The valve body of this type of soft-seal sluice valve is generally formed by lining the entire surface of a core material such as metal with an elastic material such as rubber. Normally, when lining a rubber material on a valve body core metal, a molding mold consisting of an upper mold and a lower mold is used, and at the time of molding, the entire surface of the core metal is sandwiched between the upper mold and the lower mold. Unvulcanized rubber (lining material) is poured into the molding mold from the upper surface side of the core material with a large injection pressure from the injection port provided on the upper mold. At that time, the rubber flows from the gap between the upper mold and the core metal into the gap between the lower mold and the core metal, and the lower surface side of the core metal is also lined.

In this case, the lower mold is provided with a pin for supporting the valve body, and the core metal is supported by the support pin, so that the gap between the core metal and the lower mold is maintained. The rubber poured from the upper mold side flows into the lower surface side of the core metal through this gap, and the lower surface is lined together with the upper surface. After molding, a rubber material or resin or the like is manually embedded in the portion supported by the support pin and not reached by the rubber to repair the portion. In such a molding method, in order to reduce the number and area of the rubber embedded portion, the positions supported by the support pins are suppressed to several places, and the diameter thereof is often small.

Further, as such a valve body molding method, the valve body rubber lining method in Patent Document 1 is disclosed. In this lining method, the core metal is supported by the support pins in the molding molds of the upper mold and the lower mold, and the rubber is press-fitted into the cavity with a large pressure while the gap for the lining is secured, and then the support pins. Is lowered to the outside of the gap, and press-fit rubber is buried in the support pin trace portion from the gap between the cavity and the valve body, and vulcanization is performed. As described above, there is also known a method in which the support pin is moved in the middle of the lining so that the rubber flowing from the gap between the lower mold and the valve body reaches the support pin mark and the entire surface of the valve body is lined.

In these lining methods, a large pressure acts on the core metal when injecting rubber. In order to withstand this injection pressure, the core metal for rubber lining is generally provided with a large wall thickness, and ribs are formed to ensure strength. In this case, a metal such as ductile cast iron or stainless cast steel is usually used as the material of the core metal, and these metals have a larger specific gravity than the rubber material and occupy most of the mass of the entire valve body. It has a great effect on the mass of the whole body. Therefore, when the core metal is made thick and ribs are formed, the mass of the core metal increases and the mass of the entire valve body increases. If the mass of the valve body becomes large, the workability at the time of lining or assembling the product deteriorates, and the workability at the time of replacing the valve body also deteriorates at the site, etc. There is a demand for weight reduction of gold.

In addition to this, thinning of the lining rubber is also required, which reduces the amount of rubber material used and the material cost. Since the vulcanization time of rubber is also shortened, it is possible to reduce the cost required for lining molding.

JP-A-59-194828

However, when trying to reduce the weight of the valve body by lining a core metal having a thin wall thickness and no ribs by using the valve body molding method described above, there are only a few positions to support the valve body, and the support is supported. When the diameter of the pin is also small, the core metal is easily affected by the injection pressure of the rubber, and cannot withstand this pressure and is easily deformed. On the other hand, if the diameter of the support pins is increased and the number of the support pins is increased to reduce the rubber injection pressure into the core metal, the distance between the enlarged support pins becomes narrower, and vulcanization is in progress between them. It becomes difficult for the rubber to flow in, and as a result, it may not be possible to secure an even lining thickness. Further, when embedding another rubber material, resin, or the like in the portion supported by the support pin, it is a manual work and it takes time and effort because the embedding area is large. The properties are different from the parts into which the rubber is poured during vulcanization, and it becomes difficult to form these in an even thickness. For these reasons, water infiltrates from the embedded portion after being incorporated into the valve, leading to deterioration of functionality such as rusting of the core metal.

In the case of Patent Document 1, when the support pins having a larger diameter and an increased number are lowered, the upper surface of the support pins becomes a large area, so that the gap between the upper surface and the support pin traces of the valve body becomes wider. .. For this reason, the time required for filling the rubber between them increases, and it becomes difficult to vulcanize at the same time as the rubber poured before the support pin is lowered. This makes it difficult to evenly line the entire surface of the core metal, and there is a possibility that a part of the core metal will be exposed. For this reason, in the case of lining molding using the descending support pin, it is necessary to quickly pour the rubber into the support pin mark before the rubber before the descending of the support pin is vulcanized.

Further, if it takes time to fill the support pin traces with rubber after the support pin is lowered, the valve body may be lowered in the downward direction due to the weight of the valve body and the injection pressure of the rubber. In this case, the rubber thickness between the upper surface side of the valve body and the lower surface side of the valve body is uneven, the rubber thickness of the lower surface is thinner than that of the upper surface of the valve body, and the accuracy of the valve body is lowered. Since the gap between the lower mold and the valve body becomes smaller, it becomes more difficult to quickly fill the support pin marks with rubber.

In addition to this, when the size of the support pins is increased and the number of the support pins is increased, the rubber around the support pins flows into the traces of the support pins, and the rubber thickness around the support pins becomes locally thin. Therefore, the amount (thickness) of rubber required to press and lower the support pin may be insufficient, and the support pin may not be lowered. In this case, it becomes impossible to line the support pin marks, which leads to the exposure of the core metal.

From the above, it is difficult to reduce the gap between the molding die and the core metal, and if the gap is reduced, the rubber flow path becomes narrow and it becomes difficult for the rubber to flow to the core metal. In particular, due to the structure of the molding mold, which passes through the gap between the upper mold and the core metal and the gap between the lower mold and the core metal by the time the injected rubber reaches the periphery of the support pin, it is difficult for the rubber to flow through these gaps. As a result, the entire core metal is no longer filled with rubber. Therefore, in the valve body molding method described above, it is difficult to thin the lining rubber, and the cost is high.

The present invention has been developed in order to solve the above-mentioned problems, and an object of the present invention is that the lining can be made while reducing the weight of the entire valve body by thinning the core metal without reinforcing the core metal. It is an object of the present invention to provide a valve body forming method for a soft-sealed sluice valve, which can maintain the functionality of a valve by lining the entire surface of a core metal with an equal thickness and can also reduce the lining thickness.

In order to achieve the above object, in the invention according to claim 1, the valve blade side of the core metal of the sluice valve valve body is raised in a state where a gap for lining is provided in a molding die having an upper die and a lower die. A through hole that is supported by the support surface of the support pin, press-fits the unvulcanized rubber material from the upper mold into the lined surface of the core metal, and penetrates the front and back surfaces of the core metal at a position facing the support surface. Is formed, and the periphery including the through hole is provided so as to be supportable by the support surface, the rubber material is press-fitted into the gap formed on the front and back surfaces of the core metal, and the inflow pressure of the rubber material press-fitted from the through hole is used. Pressing the support surface of the support pin and lowering the support pin to the gap generated on the lower surface of the core metal to form a gap between the support surface and the lower surface of the core metal, and press-fitting the rubber material into the gap. This is a valve body forming method for a soft-sealed sluice valve in which a rubber lining having an equal thickness is formed on the entire surface of the core metal to be lined.

According to the second aspect of the present invention, when the support surface of the support pin is pressed and lowered, the valve rod mounting portion formed on the upper part of the core metal is further supported by the support pin, and the support surface of the support pin is supported. A through hole that penetrates the front and back surfaces of the core metal is formed at a position facing the center metal, and the periphery including this through hole is provided so as to be supportable by the support surface, and the rubber material is press-fitted into the gap formed on the front and back surfaces of the core metal. In addition, the inflow pressure of the rubber material press-fitted from the through hole presses the support surface of the support pin to lower the support pin to the gap formed on the lower surface of the core metal, and rubber is formed in the gap formed on the lower surface of the valve stem mounting portion. This is a valve body forming method for a soft-sealed sluice valve in which a material is press-fitted.

According to the third aspect of the present invention, in a state where the support pin is lowered during vulcanization of the rubber material, the support pin wraps around from the outside of the gap toward the gap formed on the lower surface of the core metal or the lower surface of the valve rod mounting portion. In the valve body molding method of the soft seal sluice valve, the rubber material that is press-fitted in is filled in the gap with the rubber material that is press-fitted from the through hole and spreads in the gap in the radial direction from the bottom of the through hole. is there.

According to the invention of claim 1, the rubber material is quickly press-fitted through the through hole in addition to the gap between the molding die and the core metal, and the rubber material press-fitted onto the upper and lower surfaces of the core metal is subject to vulcanization before being vulcanized. The entire lining surface can be filled with a rubber material and vulcanized uniformly. As a result, even if the support pins are enlarged or the number of support pins is increased to narrow the distance between the support pins, the core metal is lined for the core metal lining that is thin and has no reinforcement such as ribs. The entire surface can be lined with a substantially equal thickness. From this, it is possible to secure the functionality such as water stopping by lining with high precision while reducing the weight of the entire valve body by making the thickness thin without reinforcing the core metal. Moreover, by supporting the circumference including the through hole of the core metal with the support surface, this support surface is provided in a large area to alleviate the force applied to the core metal when the rubber material is press-fitted, and the core metal is deformed. A high-quality soft-sealed sluice valve can be formed by lining between the support surface and the lower surface of the core metal through the through hole while preventing damage. In addition, since the rubber material can be easily press-fitted into the gap between the core metal and the lower mold from the through hole, the gap between the molding mold and the core metal can be reduced, and the lining thickness can be reduced to further reduce the weight and size. It is also possible to reduce the amount of rubber material used.
Further, as for the support pin, the rubber material from the through hole is press-fitted to press the support surface, so that the support pin is lowered by press-fitting the rubber material from the through hole without providing a separate lowering means for the support pin. Since the gap between the support surface and the lower surface of the core metal is flush with each other, the surface of the lining portion is not uneven and the lining is reliably performed.

According to the invention of claim 2, when the support surface of the support pin is pressed and lowered, the support surface of the support pin of the valve stem mounting portion is pressed and rubber is formed in the gap formed on the lower surface of the valve stem mounting portion. Since the material can be press-fitted, it is possible to provide a valve body in which the valve stem mounting portion is lined at the same time as the lining on the valve blade side, and the rubber material is lined and molded with an uniform thickness over the entire core metal.

According to the invention of claim 3 , the rubber material is press-fitted from the lower surface of the core metal to the support surface in a state where the support pin is lowered, and the rubber material flows so as to collect in the through hole on the upper surface of the core metal. After descending a short distance of this through hole, it spreads radially on the lower surface of the core metal and fills the gap through between the lower surface of the core metal and the support surface, making it possible to reliably line the surface of the core metal. Become.

It is a vertical cross-sectional view which shows an example of a soft seal sluice valve. It is a perspective view which shows the core metal. It is a flowchart which shows the valve body molding method of the soft seal sluice valve of this invention. It is a top view which shows the state which the core metal was set in the lower mold. FIG. 4 is a cross-sectional view taken along the line AA of FIG. It is sectional drawing which shows the valve body forming apparatus. It is sectional drawing which shows the press-fitting state of the rubber material into the molding die of FIG. It is sectional drawing which shows the state which the support pin of FIG. 7 was lowered. FIG. 4 is a cross-sectional view taken along the line BB of FIG. It is a schematic diagram which shows the flow of a rubber material through a through hole in FIG. (A) is a schematic plan view showing the flow of the rubber material. (B) is a schematic cross-sectional view showing the flow of the rubber material. It is a schematic diagram which shows the comparative example with FIG. 10. (A) is a schematic plan view showing the flow of rubber. (B) is a schematic cross-sectional view showing the flow of the rubber material.

Hereinafter, a valve body forming method for a soft-sealed sluice valve and an embodiment of the valve body forming apparatus according to the present invention will be described in detail with reference to the drawings. FIG. 1 shows an example of a soft-sealed sluice valve having a sluice valve body molded by the valve body molding method of the present invention. First, the soft-sealed sluice valve will be described.

The soft seal sluice valve 1 of FIG. 1 has a valve body 2, a valve box 3, a lid body 4, and a valve rod 5. The valve body 2 has a core metal 10 inside, and is attached to a flow path 3a provided in the tubular valve box 3 by a valve rod 5 so as to be able to move up and down in the crossing direction. A lining portion 11 is formed on the entire peripheral surface of the surface of the core metal 10 by the valve body molding method of the present invention, and the lining portion 11 is provided by, for example, a rubber material 12 such as EPDM or fluororubber.

As shown in FIGS. 1, 2, and 4, the core metal 10 is provided symmetrically with respect to the insertion direction of the valve rod 5, and the valve rod insertion hole 20 is formed through the center of the core metal 10. The valve blades 21 and 21 are formed on both sides of the valve rod insertion portion 20. A valve rod mounting portion 22 projecting in a frame shape is provided above the valve stem insertion hole 20, and a substantially cubic screw top 23 is mounted inside the valve rod mounting portion 22. Is formed with a female threaded portion 24. A male screw portion 25 formed on the valve rod 5 is screwed to the female screw portion 24, and the valve body 2 is provided so as to be able to move up and down with respect to the valve box 3 by rotating the valve rod 5 through the male screw portion 25. ing.

Plate-shaped guide portions 26 are provided on both sides of the valve blades 21 and 21 of the core metal 10 so as to be parallel to each other in the flow path direction, and a guide groove 27 is formed between the guide portions 26 and 26. An arcuate concave groove 28 is formed at the protruding portion on the front and back sides of the core metal 10, while an arc protruding portion 29 protruding from the front and back sides along the bottom surface side is formed at the lower portion of the core metal 10. ..

The core metal 10 has a lined surface 30 on which the rubber material 14 is lined, and the lined surface 30 includes an outer surface (front and back surface) of the core metal 10, an insertion surface of the valve stem 5, and a screw top 23. It has a surface and front and back surfaces of the guide portion 26.

Of these lined surfaces 30, when the core metal 10 is supported between the front and back surfaces of the core metal 10, the upper mold 41 and the lower mold 42 of the molding die 40 described later, the screw top 23 located at the lower part Through holes 50 are formed on the front and back surfaces of the mounting surface to penetrate each other. The through holes 50 are provided at positions supported by the support pins 51, which will be described later, and in the present embodiment, as shown in FIG. 2, a total of nine through holes 50 are provided.

At least one through hole 50 is provided on each valve blade 21 side of the core metal 10, and at least one is provided for each support pin 51. In this embodiment, four through holes 50 are attached to each valve blade 21. One is formed in the portion 22. In this case, it is desirable that the support pins 51 are arranged so as to be substantially at the center of the columnar support pins 51, and the support pins 51 are arranged at appropriate intervals so that they do not come into contact with each other. Further, the through holes 50 may be arranged at substantially equal intervals with respect to each valve blade 21. The diameter of the through hole 50 can be set to any size.

In FIG. 1, the lining portion 11 applied to the core metal 10 has a rubber valve seat surface 11a and a seal portion 11b, and the rubber valve seat surface 11a is embedded in the concave groove portions 28 on the front and back sides of the core metal 10. The seal portion 11b is formed so as to be thickly formed in the lower portion of the arc protrusion portion 29. The rubber valve seat surface 11a is sealed to the valve seat portion 3b provided in the valve box 3, and the seal portion 11b is sealed to the water stop surface 3c provided on the bottom side of the valve box 3, so that the flow path of the valve box 3 is formed. 3a is provided so as to be openable and closable.

The valve body forming method of the present invention is used, for example, when a lining portion 11 is formed of a rubber material 12 on the core metal 10 of the soft seal sluice valve 1 described above by transfer molding to provide the valve body 2. At the time of molding the valve body 2, the valve body molding device shown in FIG. 6 is used, and this valve body molding device has a molding die 40, a core metal 10, and a support pin 51 for supporting the core metal 10. The support pin 51 is provided below the through hole 50 as described above.

In FIGS. 6 to 9, the molding die 40 in the valve body molding apparatus has an upper die 41, a lower die 42, and a slide die 52. The upper mold 41 is provided with an upper mold portion 60 and a pressing body 61, and the lower mold 42 is provided with a lower mold portion 62 and a die plate portion 63. They are provided so as to be able to be combined with each other, and after these combinations, a cavity C for lining is formed inside. The cavity C is provided slightly larger than the core metal 10, and when the core metal 10 is supported in the cavity C, a gap G for forming a lining portion 11 is formed around the core metal 10.

The upper mold portion 60 is provided with a charging port 64 for the unvulcanized rubber material 12, and a plurality of injection ports 65 communicating with the cavity C following the charging port 64. The pressing body 61 has a pressing portion 66 that can be inserted into the loading port 64, and the pressing body 61 is mounted on the upper part of the upper form portion 60 in a state where the pressing portion 66 can be inserted into the loading port 64. When the pressing body 61 is lowered, the unvulcanized rubber material 12 in the charging port 64 is pressed by the pressing portion 66 and injected into the cavity C from the injection port 65.

Nine insertion holes 67 are formed in the lower form portion 62 at positions corresponding to the through holes 50 of the core metal 10, and the support pins 51 described above are inserted into the insertion holes 67.
The support pin 51 is provided on the die plate portion 63, is provided so as to be able to move up and down with respect to the lower form portion 62 of the lower mold 42 together with the die plate portion 63, and when lowered with respect to the lower form portion 62. The through hole 50 of the core metal 10 is provided so as to communicate with the cavity C of the lower form portion 62. The support pin 51 may be fixed to the die plate portion 63, but if it is not fixed, the support pin 51 can be removed, facilitating cleaning and maintenance.

The support pin 51 has a support surface 53 on the upper surface side thereof, and the core metal 10 is supported by the support surface 53. At this time, the periphery including the through hole 50 of the core metal 10 can be supported by the support surface 51.

The slide mold 52 is provided on both valve blade sides between the upper mold portion 60 and the lower mold portion 62 so as to be slid in the left-right direction of the valve body 2. The slide type 52 forms a concave guide groove 68 when the lining portion 11 is provided between the slide mold 52 and the concave groove portion 28 of the core metal 10. By loosely fitting a convex portion (not shown) of the valve box 3 into the concave guide groove 68, the valve body 2 can be attached to the valve box 3 so as to be able to move up and down.

Subsequently, a valve body forming method for the soft seal sluice valve of the present invention will be described. As shown in FIG. 3, the valve body molding method of the present invention includes a core metal support step, a rubber press-fitting step, and a support pin lowering step, and is shown in FIG. 1 by passing through each step via a valve body molding apparatus. A lining portion 11 is provided on the core metal 10.

In the core metal support step, first, in FIGS. 4 and 5, the core metal 10 is set in the lower mold 42 in a horizontal state. In this case, in FIG. 4, the long core rod 70 shown by the alternate long and short dash line is inserted into the valve rod insertion hole 20 shown by the broken line, and between the outer circumference of the core rod 70 and the valve rod insertion hole 20. , A gap G into which the rubber material 12 can be press-fitted is provided. In the direction orthogonal to the core rod 70, a screw-screw die 71 having a long and rectangular cross section is mounted so that the valve stem mounting portion 22 penetrates, and the outer surface of the screw-screw die 71 and the valve stem mounting portion 22 are mounted. A gap G for press-fitting the rubber material 12 is also provided between the inside and the inside of the rubber material.

When the core metal 10 is mounted, the core metal 10 has a substantially symmetrical shape centered on the valve stem 5, but the upper surface 80 and the lower surface 81 are determined because the core metal 10 is set in the mold by a positioning means (not shown). At this time, the die plate portion 63 is in a raised state with respect to the lower form portion 62, and the support surface 53 of the support pin 51 projects upward from the surface of the lower form portion 62. As a result, the lower surface 81 of the core metal 10 is supported by the support surface 53, and the support pin 51 is arranged under the through hole 50. The core metal 10 is supported by the support pin 51 in a state where both the valve blade 21 side and the periphery including the through hole 50 of the valve rod mounting portion 22 are supported by the support surface 53.

In the present embodiment, the upper surface 80 of the core metal 10 means a surface located above when the core metal 10 is attached to the molding die 40, and the lower surface 81 of the core metal 10 means a surface located below.

As shown in FIG. 6, the upper mold 41 is combined with the lower mold 42, and the slide mold 52 is attached between the upper mold portion 60 and the lower mold portion 62. As a result, a gap G is provided for the rubber material 12 for lining to flow in the molding die 40 in a state where the core metal 10 is supported from below by the support pin 51.

Next, in the rubber press-fitting step, in FIG. 6, the unvulcanized rubber material 12 is charged into the charging port 64, and as shown in FIG. 7, the rubber material 12 is injected by the pressing portion 66 by pressing the pressing body 61. It is pushed toward the inlet 65 side, and the unvulcanized rubber material 12 is press-fitted into the lined surface 30 of the core metal 10 arranged in the cavity C from the injection port 65 to fill the gaps G above and below the vulcanized rubber material 12. In this case, the support pin 51 is held in the state shown in FIG. 7 until the rubber material 12 flows through the gap G between the lower form portion 62 and the core metal 10.

As a result, the core metal 10 is supported by the outer shape side (front and back side) including the valve blade 21 other than the portion supported by the support pin 51, the valve rod insertion hole 20, and the support pin 51, which is the lined surface 30 of the core metal 10. The lining portion 11 is formed by the rubber material 12 with respect to the outer surface of the valve stem mounting portion 22 and the gap between the screw spinning die 71, the guide portion 26, and the guide groove 27 other than the portion. At this time, the concave groove portion 28 and the arc protrusion portion 29 are lined in a thick wall shape, whereby the sealing property at the time of valve closing after assembling the soft seal sluice valve 1 is ensured.

Subsequently, in the support pin lowering step, after the rubber material 12 has flowed into the gap G, the die plate portion 63 is moved downward during the vulcanization of the rubber material 12 to support the rubber material 12 as shown in FIGS. 8 and 9. Lower the pin 51. As a result, each through hole 50 provided on the valve wing 21 side and the valve rod mounting portion 22 side of the support portion by the support pin 51 is put into a penetrating state, and the support pin 51 and the lower surface on the valve wing 21 side are passed through these through holes 50. The rubber material 12 is press-fitted into the gap G between each of the eight locations and the support pin 51 and one location on the lower surface of the valve stem mounting portion 22. At this time, on the valve stem mounting portion 22 side, the rubber material 12 is press-fitted from the through hole 50 on the bottom surface side of the screw spinning top 71 and is filled between the valve rod mounting portion 22 and the support pin 51. As a result, the upper surface 80 and the lower surface 81 of the core metal 10 are filled with the rubber material 12 having a substantially uniform thickness to form the lining portion 11.

In this case, the support pin 51 is lowered by pressing the rubber material 12 from the through hole 50 and pressing the support surface 53. When the support pin 51 is moved, the support surface 53 is flush with the surface of the lower mold 42, so that unevenness on the surface of the lining portion 11 can be prevented.

In the above embodiment, through holes 50 are provided on each valve blade 21 side of the core metal 10 and the valve rod mounting portion 22, and these are supported from below by the support pin 51, but the core metal 10 If the lining portion 11 can be formed with a substantially uniform thickness as a whole, the through hole 50 and the support pin 51 may be provided at least on the valve blade 21 side. Therefore, the number of through holes 50 may be one, and the number of through holes 50 can be appropriately increased according to the nominal diameter of the valve and the like. The through hole 50 is arranged at a substantially central position of the support pin 51, but this position may be changed, and a plurality of through holes 50 of the core metal 10 are provided for one support pin 51. You may. It is also possible to change the number of support pins 51, the outer diameter dimension, the arrangement position, and the like according to the position of the through hole 50.

Next, the valve body forming method of the soft seal sluice valve in the present invention and the operation of the valve body forming apparatus in the above embodiment will be described.
As described above, in the valve body forming method of the soft seal sluice valve of the present invention, the lining portion 11 is formed on the core metal 10 through the core metal supporting step, the rubber press-fitting step, and the support pin lowering step by the valve body forming apparatus. As a result, as shown in FIGS. 1, 2 and 5, even in the case of the core metal 10 having a thin wall thickness and no ribs and weak strength, the number of support pins 51 is increased to increase the outer diameter. The core metal 10 can be firmly held, and the upper surface 80 and the lower surface 81 can be provided with lining portions 11 having substantially equal thickness while preventing the core metal 10 from being deformed.

At this time, the number and thickness of the support pins 51 are appropriately arranged according to the size of the core metal 10 according to the nominal diameter of the valve body 2, and in particular, are evenly distributed on the valve blade 21 (thin wall portion). It is desirable to arrange them in a well-balanced manner.

When the unvulcanized rubber material 12 is injected, in addition to the flow of the rubber material 12 from the surface of the core metal 10, the rubber material 12 is on the valve blade 21 side and the valve rod mounting portion 22 side even through the through hole 50. Since it flows to the lower surface side of the core metal 10, the rubber material 12 is press-fitted into the vicinity of the support pin 51 as compared with the case where the rubber material 12 flows only through the gap between the core metal 10 and the lower mold portion 62 from the surface of the core metal 10. The time required can be significantly reduced.

More specifically, in FIGS. 10 (a) and 10 (b), the arrows indicate the flow of the rubber material 12 when the support pin 51 descends in the direction indicated by the thick arrow, and the rubber material 12 indicates the flow of the rubber material 12. , It flows into the gap G between the support surface 53 and the lower surface 81 of the core metal indicated by the alternate long and short dash line. At that time, the rubber material 12 that has passed through the gap G between the core metal 10 and the lower form portion 62 is press-fitted in the direction of the broken line arrow through between the core metal lower surface 81 and the support surface 53. In addition to this, as shown by the solid arrow, the rubber material 12 flows so as to gather in the through hole 50 at the upper surface 80 of the core metal, descends a short distance of the through hole 50, and then radiates to the lower surface 81 of the core metal. The gap G between the lower surface 81 of the core metal and the support surface 53 is filled while spreading.

On the other hand, FIGS. 11 (a) and 11 (b) show comparative examples, and the core metal of this comparative example is not provided with a through hole. In this case, as shown in the figure, when the support pin 51 descends in the direction indicated by the thick arrow, the rubber material 12 passes only between the core metal lower surface 81 and the support surface 53 indicated by the broken line arrow. , The gap G between the lower surface 81 of the core metal and the support surface 53 is filled.

From the above, in the case of FIG. 10, even when the distance between the support pins 51 is narrow or the total area of the support surface 53 is large, the gap G between the core metal 10 and the lower form portion 62 When the rubber material 12 press-fitted from is reached around the support pin 51, the rubber material 12 can be press-fitted at a short distance from the through hole 50 and vulcanized at the same time. 11 can be molded. As a result, the lining portion 11 can be molded with high accuracy, the functionality of the valve body 2 after molding can be improved, and the water stopping performance can be improved. There is no need to perform repair work such as manually embedding the rubber material 12 on the lower surface 81 side of the core metal.

On the other hand, in the case of the comparative example of FIG. 11, since it takes time for the rubber material 12 to flow into the gap G between the lower surface 81 of the core metal and the support surface 53 after the support pin 51 is lowered, the support pin 51 The rubber material 12 press-fitted before lowering may be vulcanized first, and the thickness and properties of the lining portion 11 may not be uniform in the vicinity of the lower surface 81 of the core metal.

In addition to the above, in the valve body forming method of the present invention, due to the increase in the diameter and the number of the support pins 51, the pressure of the rubber material 12 press-fitted into the upper surface 80 of the core metal and the weight of the core metal 10 make this core. The gold 10 moves downward to prevent its position from being biased. As a result, the gaps G between the upper and lower surfaces 80 and 81 of the core metal 10 are evenly held, and the lining portion 11 having a uniform thickness can be formed on the entire surface of the core metal 10.

Further, since the support pin 51 is lowered by utilizing the press-fitting of the rubber material 12 into the through hole 50, the support pin 51 is securely held until the support surface 53 is flush with the surface of the lower form portion 62. It can be lowered, and it is possible to prevent the occurrence of a step on the lining portion 11 on the lower surface side and finish the surface smoothly.

From the above, since the lining portion 11 can be made thinner, the amount of the rubber material 12 used can be reduced, and the vulcanization time of the rubber material 12 can be shortened at the time of lining molding.

Next, when the core metal is supported by the valve body forming method of the soft seal sluice valve of the present invention, the difference between the outer diameter dimension and the number of support pins according to the nominal diameter is compared between the implemented product and the comparative product. did. In Table 1, the products implemented by the valve body molding method of the present invention shown in FIG. 10 and the comparative products in the case of molding by the valve body molding method shown in FIG. 11 are supported when the nominal diameters of the valves are different. The outer diameter of the pin and the number of pins are shown respectively.

From the results in Table 1, when the nominal diameter of the valve is 350, which is a relatively small diameter, the total number of the implemented products can be reduced while increasing the outer diameter dimension of the support pins 51 as compared with the comparative product. Specifically, by providing the support pin 51 of φ50 at four places and the support pin 51 of φ30 at one place, the support area of the lower surface 81 of the core metal can be widened. Even when the gold 10 is thinned and no reinforcement such as ribs is provided, the deformation can be prevented.

In the case of a relatively large valve nominal diameter 450, the outer diameter dimension and the number of the support pins 51 can be changed according to the difference in the nominal diameters, and the support area to the lower surface 81 of the core metal can be adjusted. That is, when the area of the lower surface 81 of the core metal increases as the nominal diameter increases, the support surface 53 can be supported in an increased area. As a result, even when a high pressure is applied to the core metal (core metal having a large nominal diameter) 10 having a large area on the upper and lower surfaces 80 and 81 by press-fitting the rubber material 12, a part or the whole of the core metal 10 is used. The upper and lower surfaces 80 and 81 can be appropriately lined while preventing deformation.

Regardless of the nominal diameter, in the case of the product, the rubber material 12 is filled in the trace of the support pin 51 through the through hole 50 by lowering the support pin 51, and the lining portion 11 having a uniform thickness is formed. Moreover, the rubber material 12 can be vulcanized in a homogeneous state to form a high-quality valve body 2.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the description of the embodiments, and is within the scope of the invention described in the claims of the present invention. Therefore, various changes can be made. For example, the operation method of the die plate for lowering the support pin is not particular, and the support pin can be lowered by means other than the die plate. Further, various molding means other than transfer molding can be used as long as the core metal support step, the rubber press-fitting step, and the support pin lowering step are performed.

1 Soft seal sluice valve 2 Valve body 10 Core metal 11 Lining part 12 Rubber material 21 Valve wing 22 Valve rod mounting part 30 Lined surface 40 Molded type 41 Upper type 42 Lower type 50 Through hole 51 Support pin 53 Support surface 65 Note Entrance 80 Core metal upper surface 81 Core metal lower surface G Gap

Claims (3)

The valve blade side of the core metal of the sluice valve valve body is supported by the support surface of the support pin in the raised state with a gap for lining provided in the molding die having the upper die and the lower die, and the upper die is used as described above. An unvulked rubber material is press-fitted into the lined surface of the core metal, and a through hole penetrating the front and back surfaces of the core metal is formed at a position facing the support surface, and the periphery including the through hole is formed. A rubber material is press-fitted into the gaps formed on the front and back surfaces of the core metal so as to be supportable by the support surface, and the support surface of the support pin is pressed by the inflow pressure of the rubber material press-fitted from the through hole. The core is pressed to lower the support pin to a gap formed on the lower surface of the core metal to form a gap between the support surface and the lower surface of the core metal, and a rubber material is press-fitted into the gap to form the core. A valve body forming method for a soft-sealed sluice valve, characterized in that a rubber lining having an equal thickness is formed on the entire surface to be lined with gold. When the support surface of the support pin is pressed and lowered, the valve rod mounting portion formed on the upper part of the core metal is further supported by the support pin, and the support pin is positioned at a position facing the support surface. Through holes are formed through the front and back surfaces of the core metal, and the periphery including the through holes is provided so as to be supportable by the support surface, and the rubber material is press-fitted into the gaps formed on the front and back surfaces of the core metal. The support surface of the support pin is pressed by the inflow pressure of the rubber material press-fitted from the through hole to lower the support pin to the gap formed on the lower surface of the core metal, and the gap formed on the lower surface of the valve stem mounting portion. The valve body forming method for a soft-sealed sluice valve according to claim 1, wherein a rubber material is press-fitted into the sluice. With the support pin lowered during vulcanization of the rubber material, the rubber material is press-fitted by wrapping around from the outside of the gap toward the gap formed on the lower surface of the core metal or the lower surface of the valve rod mounting portion. The first or second aspect of the present invention, wherein the rubber material to be press-fitted and the rubber material press-fitted from the lower portion of the through-hole into the gap while spreading in the radial direction are filled in the gap. How to mold the soft seal sluice valve.

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