JPH0229006B2 - DENDOYOMUTANBERUTONOSEIZOHOHOOYOBISONOSEIKEIYOKATA - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an endless conductive belt, and particularly to a method for manufacturing an endless conductive belt made of a curable elastic material with a tensile member embedded therein, and a mold for forming the belt.

(Prior art) A method for manufacturing an endless conductive belt using a curable elastic material as a liquid casting material is disclosed in, for example,
It is disclosed in Publication No. 32824. According to it,
As shown in FIGS. 12, 13, and 14, a liquid casting material 200 made of a mixture of a casting material from which air bubbles have been degassed and a hardening agent is composed of an inner mold 400 and an outer mold 401. The liquid is carefully injected into the space, or it is press-fitted by pressurizing means 600. However, air bubbles 700 are likely to be mixed into the molded product 201 obtained by these methods. These air bubbles 700 cause belt damage when the belt is used. In particular, there are air bubbles 7 at the root of the belt teeth.
If 00 occurs, it will result in fatal damage during use. These bubbles 700 are part of the belt tension body 300.
It tends to occur nearby. This is mainly due to insufficient flow within the mold due to the high viscosity of the casting material 200.

In the molding of an endless belt using the liquid casting material 200, poor mold precision also causes variations in the tooth bottom thickness of the belt, which is a cause of lowering the value of the belt product. Furthermore, when fitting the inner mold 400 to the outer mold 401, the inner mold 4
The tensile body 300 wound around the outer circumferential surface of the tensile body 300 may become misaligned and may not function as the tensile body 300. Removal of burrs formed in the injection hole 402 or the degassing hole 403 is also complicated. Secondary processing such as grinding is required to remove burrs. Therefore, work efficiency is extremely poor.

In order to eliminate the above drawbacks, centrifugal molding methods, vacuum suction injection methods, and the like have been proposed. For example, the first
The centrifugal molding method (Japanese Patent Publication No. 55-32527) shown in FIG. 5 has advantages such as less generation of air bubbles 700, mass production, and less finishing margin. However, this method has drawbacks such as requiring a large amount of equipment and requiring high mold accuracy. In addition, the vacuum suction injection method shown in Fig. 16 (Japanese Patent Publication No. 47-32824)
is extremely effective in removing the bubbles 700, but
This has the disadvantage that the device becomes larger and the equipment becomes more expensive. It is also difficult to remove burrs remaining in the injection hole 402.

(Objective of the Invention) An object of the present invention is to provide a method for manufacturing an endless conductive belt that prevents the generation of bubbles in a liquid casting material and has excellent durability. Another object of the invention is to
It is an object of the present invention to provide a method for producing an endless belt for transmission in which burrs can be easily removed after molding. Still another object of the present invention is to provide a mold for carrying out the above method.

(Structure of the Invention) The manufacturing method of the present invention includes (1) winding a tensile member around the mold surface of a cylindrical inner mold in a direction perpendicular to a plurality of grooves parallel to the mold axis direction; and (2) a step of fitting the inner mold in an air-liquid tight manner into an outer mold whose inner peripheral surface has a cylindrical shape and is provided with an injection hole and an openable and closable degassing hole to form a predetermined cavity part. and (3) filling the cavity with the liquid casting material from the injection hole under pressure using a pressurizing means that is engaged with the injection hole in an air-liquid tight manner, and evacuating the air in the cavity through the degassing hole. (4) closing the deaeration hole; (5) pressurizing the cast material in the cavity with the pressurizing means; and (6) a molded product obtained by curing the cast material. The above object is achieved by separating the molded product from the mold together with the burr formed at the same time as the molded product. The mold of the present invention capable of carrying out the above method includes (1) an outer mold having a cylindrical inner peripheral surface;
It has a cylindrical inner mold that can be fitted into the mold in an air-liquid tight manner to form a predetermined cavity portion and has a plurality of grooves parallel to the mold axis on the mold surface, (2) the inner mold A tensile member is wound on the mold surface in a direction perpendicular to the groove,
(3) The outer mold has a liquid casting material injection hole and a degassing hole that can be opened and closed, and (4) the injection hole has a pressurizing means for pressurizing and filling the casting material into the cavity. The above object is thereby achieved.

(Example) The present invention will be described below with reference to Examples.

The belt forming mold 1 of the present invention has an inner mold 11 and an outer mold 12, as shown in FIGS. 1 to 5.
The outer mold 12 has an inner peripheral surface 120 having a cylindrical shape. For example, an injection hole 121 is located at the bottom corner of this outer mold 12.
is provided. This outer mold 12 further includes:
A deaeration hole 122 is provided. This deaeration hole 12
2 is located as far away from this injection hole 121 as possible, for example, at a position that is approximately symmetrical with this injection hole 121 with respect to the center 100 of the outer mold 12 . The inner mold 11 is formed into a cylindrical shape and is fitted into the outer mold 12 in an air-liquid tight manner to form a predetermined cavity portion 13. A pressurizing means 14 is engaged with the injection hole 121 . This is to transfer the liquid casting material 2 to the cavity part 13.
This is for pressurized filling.

The inner mold surface 110 is provided with a plurality of grooves 111 parallel to the mold axis direction, and the tensile body 3 is inserted into the grooves 11.
It is wound in a direction perpendicular to 1. As the tensile member 3, for example, a rope-like material such as a synthetic fiber rope, a steel wire, a glass fiber rope, or a woven fabric is used. The upper end 112 of the inner mold 11 forms a fixing flange for engaging with the outer mold 12. The outer mold 12 has a corresponding flange 123. The flanges 112 and 123 are pressed by pressure P ₁ and P ₂ by the pressure means 14.
is fixed with a force F sufficient to resist. As the tightening means, bolting, a hydraulic cylinder, a clamp, etc. are used as appropriate. It is not particularly limited to flanges as long as the inner mold 11 and the outer mold 12 are fixed with a force F sufficient to resist the pressurizing forces P ₁ and P ₂ . Furthermore, the inner mold 11 has a sealing mechanism 116 at the upper and lower parts thereof to fit into the outer mold 12 in an air-liquid tight manner. This sealing mechanism 116
is constructed by arranging an elastic sealing material such as an O-ring on the outer wall surface in contact with the outer mold 12, for example.
Even if this sealing mechanism 116 is provided on the inner wall of the outer mold 12, its function remains the same. Inner mold 11
is the outer mold 12 via this sealing mechanism 116.
The cavity portion 13 is fitted in a gas-liquid tight manner and has a gap of at least 0.3 mm. This cavity portion 13 forms a desired endless belt shape. Positioning protrusions 114 and 115 are provided at upper and lower ends 112 and 113 of the inner mold 11, respectively. These protrusions are provided to prevent the tension body 3 wound around the inner mold surface 110 from coming into contact with the outer mold 12 and causing thread displacement when the inner mold 11 is fitted into the outer mold 12. . The shape of the protrusions 114 and 115 is, for example, a shaft shape or a hook shape.

The penetration direction of the injection hole 121 provided at the bottom corner of the outer mold 12 is in the mold axis direction. The diameter of the injection hole 121 is appropriately selected depending on the capacity of the cavity portion 13, the type of casting material 2, the degree of processing, and the like.
For example, it is set to about 8 mm. This injection hole 121
Regarding this, the diameter of the deaeration holes 122 provided at positions approximately symmetrical with respect to the center 100 of the outer mold is also appropriately selected depending on the capacity of the cavity portion 13, the type of casting material 2, the degree of processing, etc. For example, about 2 mm is adopted. This deaeration hole 122 is located on the outer periphery of the outer mold 12.
It is formed into a conical shape with an angle of 60°. The deaeration hole opening/closing valve 124 for opening and closing the deaeration hole 122 is composed of, for example, a needle. The conically expanding deaeration hole 122 is sealed air-liquid-tightly by the tip of the needle, which also has a conical shape.
The on-off valve 124 is engaged with a bracket 125 fixed to the outer mold 12, for example, via screw means 126. The degassing hole opening/closing valve 124 is not limited to the above needle as long as it can close or open the degassing hole 122 in a gas-liquid tight manner. Accordingly, the engagement method of the on-off valve 124 may also be selected as appropriate.

The pressure means 14 engaged with the injection hole 121
For example, the casting material storage container 141, the piston 140 that can fit therein, and the storage container 141
It is composed of a pressure medium 142 for pushing up the piston 140 toward the piston 140. This piston 140 is
A through hole 143 that communicates from the injection hole 121 to the cavity portion 13 through the center thereof, and this piston 14
0 and a sealing mechanism 144 such as an O-ring provided around the 0. The piston 140 closes the casting material storage container 1 by this sealing mechanism 144.
41 in an air-liquid tight manner. This piston 140
Further, the piston through hole 143 is removably engaged with the outer mold wall near the injection hole 121 via a sealing mechanism 145 such as an O-ring so that the piston through hole 143 can be engaged with the injection hole 121 in a gas-liquid tight manner. be done.
At this time, the piston through hole 143 and the injection hole 121
are consistent on a straight line. This storage container 14
1 is pushed up by a pressure medium 142, such as a cylinder, at a pressure P ₁ , the casting material 2 in the container 141 is pushed up through the piston through hole 143 and the injection hole 12.
1 to fill the cavity 13 under pressure. The pressure medium 142 is not limited to the above-mentioned cylinder as long as it pressurizes and maintains the casting material 2 at a predetermined pressure, and a plunger pump, compressed air pump, etc. may also be used. As the liquid casting material 2, a curable elastic body such as a liquid rubber such as chloroprene rubber or butadiene rubber, a curable resin such as liquid polyurethane, or plastisol is used.

An example of a method for manufacturing an endless conductive belt using the above-mentioned mold 1 of the present invention will be described below.

Liquid casting material 2 contains a prepolymer as a main ingredient.
Use 200g and keep it warm at 80℃. On the other hand, as an auxiliary agent, 0.4 g of adipic acid and an appropriate amount of mocha are mixed under heating and kept at 110°. After vacuum degassing each of these using existing equipment, they are mixed and stirred and placed in the storage container 14.
1. On the other hand, the inner mold 11 and the outer mold 12
They are heated to 110° C., and while maintaining this temperature, they are fitted in an air-liquid tight manner to form a predetermined cavity portion 13. A piston 140 is attached to the outer mold injection hole 121, and as shown in FIG.
41 is pushed up using a pressure medium 142 at a predetermined pressure _P1 . The casting material 2 is injected from the container 141 into the cavity 13 through the piston through hole 143 and then through the injection hole 121 . At this time, the deaeration hole 122 is in an open state, and the air in the cavity 13 is pushed up by the casting material 2 and the deaeration hole 122 is in an open state.
2, it is discharged from the system. After the casting material 2 fills the inside of the cavity 13, it overflows from the degassing hole 122. Depending on the injection speed and the viscosity of the casting material 2, the casting material 2 overflowing from the degassing hole 122 may trap air inside the cavity 13, and even after filling, this air may flow out from the open degassing hole 122. A small amount is emitted. Next, as shown in FIG. 6, the deaeration hole opening/closing valve 124 is screwed into the deaeration hole 122 from the outside to seal the deaeration hole 122. Further, the storage container 141 is pushed up by the pressure medium 142. As a result, the pressure inside the cavity 13 is normally 10 to
It is maintained at a predetermined pressure P ₂ of 50 Kg/cm ² , preferably within the range of 15 to 30 Kg/cm ² . Since the mold 1 is heated to 110° C., it is usually kept in this state for about 45 minutes until the casting material 2 hardens. After curing, as shown in FIG. 7, the container 141 is lowered at a predetermined pressure _P3 . In this way, the sealing mechanism 116 and the deaeration hole opening/closing valve 12
4 and the like, the inside of the cavity 13 is isolated from the outside air and a predetermined pressure is sufficiently applied, so that the internal pressure of the casting material 2 is maintained at a predetermined level. Therefore, even if the casting material 2 is not fully defoamed even after the casting material 2 has hardened, or even if air is trapped inside the cavity 13, the casting material 2 will not be able to be poured due to the relationship between the viscosity of the gas and the liquid. By the time the mold material 2 has hardened, the bubbles have effectively shrunk. After lowering the container 141, the burr 146 generated in the boundary area between the container 141 and the piston 140 is cut off using a cutter, for example. Next, as shown in FIG. 8, the endless belt molded product 20 obtained by curing is separated from the outer mold 12 together with the inner mold 11. At this time, the molded product 20 has burrs generated in the piston through hole 143, the injection hole 121, and the degassing hole 122.
47, 148 and 149 remain attached.
At this time, the molded product 20 adheres to the inner mold 11 because the outer peripheral surface area of the inner mold 11 is theoretically wider than the inner peripheral area of the outer mold 12. However, there is no problem even if the outer mold 12 is subjected to some kind of processing, the molded product 20 is attached thereto, and only the inner mold 11 is separated. For example, the outer mold 12 is processed with grooves. The molded article 20 is then separated from the inner mold 11. Next, the burrs 146 and 147 attached to the molded product 20 are cut off using a cutter or the like. As shown in FIG. 9, since the burr 149 generated in the deaeration hole 122 is located in the unwound portion of the tensile material, it becomes a loss when the tensile material is later cut into rounds of a predetermined width and is discarded. Finally, this molded product 2
Cut 0 into rounds to the specified width. The endless conductive belt manufactured in this manner can minimize air bubbles and provide excellent durability. Moreover, since the burrs are formed parallel to the mold axis direction, separation and removal of the burrs is extremely easy. In addition, since the molding mold 1 of the present invention directly fits the inner mold 11 and the outer mold 12 at the upper and lower fitting parts having a sealing mechanism 116 such as an O-ring, the resulting belt has excellent dimensional accuracy. No variation in thickness occurs. As an example of the application of the present invention, as shown in Figs. 10 and 11, roll products with excellent durability and minimized air bubble generation can be produced instead of belts. can be supplied. In this case, the inner mold 11 serves as a roll core shaft and functions as a part of the final roll-formed product.

(Effects of the Invention) As described above, the manufacturing method of the present invention and its mold can prevent the generation of air bubbles regardless of the viscosity if it is a castable curable elastic material, and can prevent wall thickness variations and resistance. It is possible to supply an endless conduction belt with excellent durability without causing thread displacement of the tension body. Its durability is not affected by the winding pitch of the thread or the thickness of the belt. Dimensional accuracy is also extremely high. In addition, it is extremely easy to remove the product and cut off burrs when separating the molds.

[Brief explanation of drawings]

FIG. 1 is a front view showing one embodiment of the inner mold of the mold for molding of the present invention, FIG. 2 is a front sectional view showing the outer mold, FIG.
The figure is a front cross-sectional view of the main part showing the degassing hole of the outer mold, FIG. 5 is a front cross-sectional view showing an embodiment of the molding mold of the present invention, and FIGS. 6 and 7 are a front cross-sectional view of the mold of the present invention. FIGS. 8 and 9 are front sectional views and partial detailed views of main parts showing one embodiment of the method for producing an endless belt of the present invention, and FIGS. Detailed drawing, No. 10
Figures 11 and 11 are front sectional views showing other embodiments of the molding mold of the present invention and front sectional views showing an example of a molded product manufactured using the same, and Figures 12 and 13 are conventional belt molding FIG. 14 is a front sectional view of a main part showing an example of a mold, FIG. 14 is a perspective sectional view of a main part of a belt manufactured using a conventional mold, and FIGS. 15 and 16 are a front sectional view of a belt manufactured using a conventional belt mold. FIG. 7 is a front sectional view of a main part showing another example. 1...Molding mold, 2,200...Liquid casting material,
3,300...Tensile body, 11,400...Inner mold,
12,401... Outer mold, 13... Cavity part,
14,600...pressure means, 20,201...molded product, 100...outer mold center, 110...inner mold surface, 111...inner mold groove, 112...inner mold upper end,
113... Inner mold lower end, 114, 115... Inner mold protrusion, 116, 144, 145... Sealing mechanism, 120... Outer mold inner peripheral surface, 121, 402...
Injection hole, 122, 403... Degassing hole, 123...
Flange, 124... Deaeration hole opening/closing valve, 125...
Bracket, 126...Screw means, 140...Piston, 141,500...Liquid casting material storage container, 142...Pressure medium, 143...Through hole, 1
46,147,148,149... Bali, 700
...Bubble, 800...Vacuum means.

Claims (1)

[Claims] 1 (1) A step of winding a tensile member on the mold surface of a cylindrical inner mold in a direction perpendicular to a plurality of grooves parallel to the mold axis direction provided on the mold surface. , (2) a step of forming a predetermined cavity portion by fitting the inner mold into an outer mold having a cylindrical inner peripheral surface and having an injection hole and an openable and closable deaeration hole in an air-liquid tight manner; ) Filling the cavity with a liquid casting material from the injection hole under pressure using a pressurizing means engaged with the injection hole in a gas-liquid tight manner, and deaerating the air in the cavity from the degassing hole; , (4) closing the deaeration hole; (5) pressurizing the cast material in the cavity with the pressurizing means; and (6) converting the molded product obtained by curing the cast material into the molded product. A method for producing an endless conductive belt, which includes the step of simultaneously separating the formed burrs from the mold. 2. The manufacturing method according to claim 1, wherein the inner mold has positioning protrusions at upper and lower ends along the mold axis. 3. The manufacturing method according to claim 1, wherein the inner mold and the outer mold are fitted in an air-liquid tight manner by a sealing mechanism provided on the outer wall of the inner mold or the inner wall of the outer mold. 4. The manufacturing method according to claim 1, wherein the injection hole is provided so that its penetration direction is parallel to the mold axis direction. 5. The manufacturing method according to claim 1, wherein the deaeration hole is opened and closed in a gas-liquid tight manner by a deaeration hole opening/closing valve attached to the outer mold. 6. The manufacturing method according to claim 5, wherein the deaeration hole opening/closing valve is engaged with a bracket of the outer mold. 7. Claim 5, wherein the on-off valve is a needle that is engaged with the bracket by screw means.
The manufacturing method according to item 6 or item 6. 8. The manufacturing method according to claim 1, wherein the injection hole and the deaeration hole are provided at positions that are approximately symmetrical with respect to the center of the outer mold. 9. Claim 1, wherein the pressurizing means comprises a casting material storage container, a piston that can fit into the storage container in an air-liquid tight manner, and a pressure medium that presses the storage container in the direction of the piston. The manufacturing method described in. 10. The manufacturing method according to claim 9, wherein the piston has a through hole passing through the center thereof, and the through hole and the injection hole are aligned in a straight line. 11. The manufacturing method according to claim 9, wherein the piston is removably attached to the outer mold near the injection hole and is engaged in a gas-liquid tight manner. 12. The manufacturing method according to claim 1, wherein the casting material filled in the cavity is maintained at a pressure in the range of 10 to 50 kg/cm ² by the pressurizing means. 13. According to claim 1, the molded product is separated from the outer mold along the mold axis direction together with the burr and the inner mold, and then the molding machine is separated from the inner mold. manufacturing method. 14 (1) An outer mold having a cylindrical inner peripheral surface, which can be fitted into the outer mold in an air-liquid tight manner to form a predetermined cavity, and a plurality of grooves parallel to the mold axis direction are provided on the mold surface. (2) a tensile member is wound around the mold surface of the inner mold in a direction perpendicular to the groove, and (3) the outer mold has a liquid casting material injection hole and an opening/closing hole. and (4) a pressurizing means for pressurizing and filling the casting material into the cavity portion is engaged with the injection hole. 15. The mold according to claim 14, wherein the inner mold has positioning protrusions at upper and lower ends along the mold axis. 16. The mold according to claim 14, wherein the inner mold and the outer mold are fitted in an air-liquid tight manner by a sealing mechanism provided on an outer wall of the inner mold or an inner wall of the outer mold. 17. The mold according to claim 14, wherein the injection hole has a penetrating direction in the mold axis direction. 18. The mold according to claim 14, wherein the deaeration hole is opened and closed in a gas-liquid tight manner by a deaeration hole opening/closing valve attached to the outer mold. 19. The molding mold according to claim 18, wherein the deaeration hole opening/closing valve is engaged with a bracket of the outer mold. 20. The mold according to claim 18 or 19, wherein the on-off valve is a needle that is engaged with the bracket by screw means. 21. The mold according to claim 14, wherein the injection hole and the deaeration hole are provided at positions that are approximately symmetrical with respect to the center of the outer mold. 22. Claim 14, wherein the pressurizing means comprises a casting material storage container, a piston that can fit into the storage container in a gas-liquid tight manner, and a pressure medium that presses the storage container in the direction of the piston. The mold described in . 23. The mold according to claim 22, wherein the piston has a through hole passing through the center thereof, and the through hole and the injection hole are aligned in a straight line. 24. The mold according to claim 22, wherein the piston is removably attached to the outer mold near the injection hole and is engaged in a gas-liquid tight manner.