JPH0438130Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> This invention is applicable to the cylinder tubes of various cylinders such as hydraulic cylinders, and the accommodation of reverse osmosis membranes in reverse osmosis membrane devices that use reverse osmosis membranes to produce pure water. This invention relates to a pressure-resistant cylinder suitable as a cylinder.

<Prior art> Conventionally, as a pressure cylinder, for example,
The one described in Publication No. 150725 is known. This conventional pressure cylinder has a cylindrical body made of fiber-reinforced plastic (FRP) made by reinforcing resin with continuous reinforcing fibers using the filament winding method, and has an inner surface at each end in the length direction of the body. The end plate is formed with a threaded portion into which the end plate is screwed. In the threaded part, continuous fibers are arranged along the threads to facilitate the formation of the threads, but since the pitch of the threads is very small, the arrangement direction is mostly in the circumferential direction of the main body. It's getting old. However, such conventional pressure cylinders have problems as explained below.

In other words, in such a pressure cylinder, when internal pressure is applied, a force is applied to the end plate to push it outward in the length direction of the main body.
In the conventional pressure cylinder described above, reinforcing continuous fibers are arranged approximately in the circumferential direction of the main body at the threaded portion where the end plate is screwed, and the direction of the continuous fibers is approximately perpendicular to the direction in which force is applied. Because of this, the withstand pressure is very low. This is because FRP is a highly anisotropic material that exhibits high strength in the direction of the fibers, but its strength rapidly decreases as it moves away from the fibers. be. That is, in the conventional pressure cylinder, in terms of the locking force of the end plate against internal pressure, the continuous fibers are arranged in the direction where the locking force is least likely to be exerted.

<Problems to be solved by the invention> The purpose of this invention is to solve the above-mentioned problems of conventional pressure-resistant cylinders, and to create a pressure-resistant cylinder that has a large end plate locking force and can be used even under higher internal pressure. is to provide.

<Means for Solving the Problems> In order to achieve the above object, this invention has a cylindrical main body made of fiber-reinforced plastic made by reinforcing a resin with continuous reinforcing fibers, and the main body has a cylindrical body made of fiber-reinforced plastic reinforced with continuous reinforcing fibers. is ±45 to 60° to the length direction of the main body above.
each longitudinal end of the main body is provided with an inverted triangular enlarged diameter portion with an inner surface facing inside the main body in cross section; A ring-shaped locking member having a triangular cross section is locked on the outside of the inner surface of the part, and a retaining ring separate from the locking member is locked on the inner surface of the locking member. The pressure cylinder is characterized in that the ring locks an end plate and a seal plate that are installed in the main body.

In this idea, the main body is made of FRP, which is made by reinforcing resin with continuous reinforcing fibers.

The resin constituting the FRP matrix is preferably a thermosetting resin such as an epoxy resin, a phenol resin, an unsaturated polyester resin, or a vinyl ester resin, but may also be a thermoplastic resin such as a nylon resin. Continuous fibers reinforcing such matrix resins include high-strength fibers such as carbon fibers, glass fibers, organic high-modulus fibers (such as polyaramid fiber "Kevlar" manufactured by DuPont in the United States), alumina fibers, and silicon carbide fibers. , a high modulus fiber.

Further, the main body has a cylindrical shape, and the above-mentioned reinforcing continuous fibers are in the range of ±45 to 60°, preferably about ±55° with respect to the length direction of the main body.
It essentially contains layers arranged at an angle of .
By adopting such an arrangement angle, the direction of reinforcement by the continuous fibers closely matches the stress state actually occurring, and the main body can withstand high internal pressure.

In other words, in a cylindrical body made of FRP, when the arrangement angle of continuous reinforcing fibers in the longitudinal direction is φ, according to the well-known network theory, stress can be calculated by considering only the tension σ _G in the fiber direction. , Therefore, the longitudinal stress σ _L and the circumferential stress σ _C of the cylinder are as follows: σ _L =σ _G cosφ σ _C =σ _G sinφ (σ _C /σ _L )=tanφ. Furthermore, as is known from material mechanics, the stress generated in a cylindrical body subjected to internal pressure is that the stress in the circumferential direction is twice the stress in the longitudinal direction, and 2σ _L = σ _C , so in the end, φ = 54.5° becomes. In other words, the arrangement angle of continuous fibers is approximately ±
When the angle is 55°, the cylindrical body has approximately the same strength against internal pressure, and the design makes effective use of continuous fibers.

On the other hand, in this invention, when internal pressure acts on the main body, a force that tries to push the end plate is applied to a separate locking member via the retaining ring. In other words, a force acting outward in the longitudinal direction of the main body acts on the locking member, but this force is caused by the fact that the outer surface of the locking member, which has a triangular cross section, and the inner surface of the locking member, which has a triangular cross section, are directed toward the inside of the main body. Since it is once locked on the inner surface of the inverted triangular enlarged diameter section, it acts to push the main body outward. In other words, the degree of locking between the main body and the locking member is such that the main body is less likely to deform in the circumferential direction.
The higher the rigidity in the circumferential direction, the stronger it becomes. For this purpose, it is best to have the continuous fibers wound in the circumferential direction of the main body at the position where the locking member is present, but the main body is also stressed in the longitudinal direction due to internal pressure. occurs, so considering the balance between stress in the circumferential and longitudinal directions and rigidity in the circumferential direction, the arrangement angle should be ±45 to 60° as described above.
This means that a range of is good. However, in addition to layers of continuous fibers arranged at such angles,
Some portions may also include layers of continuous fibers arranged at other angles, such as lengthwise or circumferentially. Note that the main body can be formed by a well-known filament winding method using a mandrel.

Now, as described above, each longitudinal end of the main body is provided with an inverted triangular enlarged diameter portion whose inner surface faces toward the inside of the main body in cross section. A ring-shaped locking member having a triangular cross section is locked on the outer surface of the enlarged diameter portion.
That is, the enlarged diameter portion supports the locking member, and it is necessary to prevent the locking member from easily coming off even if internal pressure of the main body is applied via the end plate or the retaining ring. Although the degree of diameter expansion depends on the diameter of the main body, it is preferable that the angle indicated by the symbol θ in FIG. 2 be in the range of 5 to 30 degrees.

The locking member supports the end plate in cooperation with a separate retaining ring, and is made of stainless steel or aluminum alloy, which has excellent strength, has no directionality in terms of strength, and has excellent corrosion resistance. , a metal such as a magnesium alloy. As described above, this locking member has a triangular cross section, and its outer surface is an inverted triangular expanded portion with the inner surface facing inside the main body in the cross section. Since the stress is fixed to , the generated stress can be averaged and the maximum stress can be lowered. Note that the outer surface of the locking member and the inner surface of the main body may be joined.

The end plate supports the internal pressure of the main body in cooperation with the locking member and a separate retaining ring. Therefore, it is preferable that the locking member is made of the same material as the locking member, especially a material with high surface pressure strength.

The seal plate is used to keep the main body liquid-tight and does not support internal pressure, so it does not need to be particularly strong. Plastic etc. are also sufficient.

<Example> In FIG. 1, a pressure cylinder has a cylindrical body 1 made of FRP made of resin reinforced with reinforcing continuous fibers. An enlarged diameter portion 2 is provided at one end in the length direction of the main body 1. A similar enlarged diameter section 3 is also provided at the other end.

Referring to FIG. 2, the enlarged diameter portion 2 at one end of the main body 1 has an inverted triangular shape in cross section with the inner surface facing toward the inside of the main body 1. A ring-shaped locking member 4 having a triangular cross section is locked on its outer surface. This locking member 4 is provided with a circumferential groove on its inner surface, and a snap ring 5 separate from the locking member is locked in the circumferential groove. Also,
The main body 1 is equipped with a perforated disc-shaped end plate 6 and a seal plate 7, and the retaining ring 5 locks the end plate 6 and the seal plate 7. The end plate 6 is located in the enlarged diameter portion 2,
The seal plate 7 is located in a non-diameter portion that is more inward than the expanded diameter portion 2 . Further, a liquid introduction pipe 10 is attached to the end plate 6 by screwing or welding. Furthermore, the seal plate 7
An O-ring 8 is fitted on the outer circumferential surface of , and another O-ring 9 is fitted on the surface in contact with the end plate 6 . The other end of the main body 1 is constructed in exactly the same manner as the one end. However, as shown in FIG. 1, a liquid outlet tube 11 is attached to the other end instead of the liquid inlet tube. However, depending on the application, the end plate or seal plate may be made without holes.
The other end can also be sealed.

To explain a more concrete example of this idea, a steel mandrel with a diameter of 200 mm and a length of 1500 mm is
mm spacing, with a maximum outer diameter of 240mm and an inner diameter of 200.5mm
A locking member made of stainless steel as shown in FIG. 2 was fitted and fixed.

Next, using epoxy resin as the resin and glass fiber (roving) as the reinforcing continuous fiber, a 20 mm thick wound layer was formed on the mandrel and the locking member by the filament winding method. The epoxy resin is cured by heating at a temperature of approximately 120°C for approximately 2 hours, and then the mandrel is pulled out and engaged at the enlarged diameter portions at each longitudinal end of the main body, as shown in Figure 2. The stop member was locked. Note that the arrangement angle of the glass fibers with respect to the length direction of the mandrel was ±55°.

Next, a pressure cylinder as shown in Figures 1 and 2 was assembled using a stainless steel retaining ring, a stainless steel end plate, a vinyl chloride seal plate, and a rubber O-ring. . Note that the end plate and seal plate on the side of the liquid outlet tube 11 in FIG. 1 were those having no holes, and the ends thereof were sealed. The liquid inlet tube was made of stainless steel and was attached to the end plate by screwing.

Next, when the above-mentioned pressure cylinder was subjected to a water pressure test, no water leakage was observed even at a water pressure of about 240 kg/cm ² .

<Effects of the invention> This invention provides a ring-shaped locking member with a triangular cross section on the inner surface of the enlarged diameter part of the main body, which has an inverted triangular shape and whose inner surface faces the inside of the main body in the cross section. Since it is locked, when internal pressure is applied, the stress that tries to spread the main body can be averaged and the maximum stress can be lowered. Therefore, as shown in the examples, the withstand pressure is greatly improved.

In addition, since the main body essentially includes a layer in which continuous fibers are arranged at an angle of ±45 to 60°, preferably about ±55° with respect to the length direction, continuous fibers The direction of the reinforcement will closely match the state of stress that occurs when internal pressure is applied to the main body, and the pressure resistance will also improve from this aspect.

Furthermore, since the end plate and seal plate are locked by a retaining ring that is separate from the retaining member, disassembly and assembly are easier than when the retaining member and retaining ring are integrated. .

Furthermore, the main body can be formed by a filament winding method using a mandrel, and at that time, a locking member separate from the retaining ring can be embedded in the main body to lock it,
Moreover, even if this is done, since the locking member is ring-shaped, the mandrel can be pulled out, and molding becomes extremely easy.

[Brief explanation of the drawing]

1 and 2 are schematic diagrams showing a pressure cylinder according to an embodiment of the invention, with FIG. 1 being a perspective view and FIG. 2 being a longitudinal sectional view of the main parts. 1... Main body, 2... Expanded diameter section, 3... Expanded diameter section, 4
... Locking member, 5 ... Retaining ring, 6 ... End plate, 7 ...
...Seal plate, 8...O-ring, 9...O
-Ring, 10...liquid inlet pipe, 11...liquid outlet pipe.

Claims (1)

[Scope of utility model registration request] It has a cylindrical body made of fiber-reinforced plastic made by reinforcing a resin with continuous reinforcing fibers, and the body has a cylindrical body in which the continuous fibers extend within ±45 mm with respect to the length direction of the body.
comprising layers arranged at angles ranging from ~60°,
Each end in the length direction of the body is provided with an enlarged diameter portion having an inverted triangular shape with the inner surface facing inside the main body in cross section, and the inner surface of the enlarged diameter portion has a ring shape with a triangular cross section. A locking member is locked on its outer surface, and a retaining ring separate from the locking member is locked on the inner surface of the locking member, and the retaining ring is connected to an end plate and a seal plate built into the main body. A pressure-resistant cylinder characterized by being locked.