JPH0461985B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a pressure vessel made of a composite material that is suitably used as a tube for a hydraulic cylinder, a pneumatic cylinder, etc., a container for liquefied gas or compressed gas, etc.
In particular, the present invention relates to a pressure vessel made of a composite material that uses fiber-reinforced resin material to significantly improve pressure resistance and the like.

[Prior art]

FIGS. 9 and 10 show a hydraulic cylinder tube as a conventional pressure vessel made of a composite material.

In FIG. 9, reference numeral 1 indicates a tube body formed into a cylindrical shape from a fiber-reinforced resin material (composite material). The molded material is formed by winding the molded material (not shown) and curing it with heat, and then pulling out the molded material. A ring groove 1A is formed on the inner periphery of the axial end of the tube body 1,
A substantially C-shaped retaining ring 2 is mounted within the ring groove 1A. 3 is tube body 1
The cover 3 is formed of a metal material or the like in the shape of a thick disk,
It is fitted onto the inner peripheral side of the axial end of the tube body 1. An oil supply/discharge port 3A is bored in the center of the cover 3, and the supply/discharge port 3A is adapted to supply and discharge pressurized oil from the outside into the tube body 1. Additionally, an O-ring 4 is provided on the outer circumferential side of the cover 3.
is installed to prevent the pressure oil inside the tube body 1 from leaking to the outside.

Thus, in the hydraulic cylinder tube configured in this way, after the cover 3 is fitted to the axial end of the tube body 1, the retaining ring 2 is installed in the ring groove 1A, and the inner circumference of the retaining ring 2 is By locking the side to the end face of the cover 3, the cover 3 is prevented from coming off, and the internal pressure acting on the cover 3 is received by the retaining ring 2 installed in the ring groove 1A of the tube body 1. It's becoming like that.

Next, in FIG. 10, reference numeral 11 indicates another tube body formed similarly to the tube body 1, and a male thread 11A is formed on the outer peripheral side of the axial end of the tube body 11. A cover 12 is screwed on. Here, the cover 1
2 is formed of a metal material or the like into a cylindrical shape with a bottom, and a female thread 12B is formed on the inner peripheral side of the cylindrical portion 12A to be screwed into the male thread 11A. In addition, the cover 1
An oil supply/discharge port 12C is bored in the center of the bottom of the tube 2, and the supply/discharge port 12C is adapted to supply and discharge pressurized oil from the outside into the tube body 11. An O-ring 13 is installed between the bottom of the cover 12 and the axial end surface of the tube body 11, so that the internal pressure acting on the cover 12 is received between the male thread 11A and the female thread 12B. It's summery.

[Problem that the invention seeks to solve]

However, each of the above-mentioned conventional techniques has the following drawbacks.

First, in the prior art shown in FIG. 9, the inner periphery of the axial end of the tube body 1 made of fiber-reinforced resin material is grooved to form the ring groove 1A. The fiber material is cut at the ring groove 1A, which significantly reduces the original strength of the fiber material, and
There is a drawback that delamination tends to occur between the wound layers of the fiber material from the periphery of the ring groove 1A, impairing reliability.

Further, in another conventional technique shown in FIG.
is formed by thread processing, so the male thread 1
The fiber material is also cut at the 1A portion, resulting in a decrease in strength and a tendency for delamination to occur, which similarly impairs reliability.

For this reason, in each of the above-mentioned conventional techniques, not only does the strength of the tube bodies 1, 11 themselves decrease, but when the internal pressure increases, the ring groove 1A and the male thread 11A are damaged, and the covers 3, 12 fall off. There is a drawback that pressure resistance performance etc. cannot be improved.

The present invention has been made in view of the above-mentioned shortcomings of the prior art.The present invention provides a pressure vessel made of a composite material that makes full use of the strength of the fiber material and can significantly improve pressure resistance, etc. There is a particular thing.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention includes an inner cylinder, a cover that is fitted onto an axial end of the inner cylinder and closes the axial end of the inner cylinder, and a cover on the outer peripheral side of the cover. A plurality of hook portions are provided for hooking and guiding the fiber material, and a fiber material impregnated with resin is hooked on each of the hook portions from the outer circumferential surface of the inner cylinder to the outer circumferential surface of the cover. It adopts a structure consisting of an outer cylinder formed by winding while unwinding.

Further, the cover has a large diameter part and a small diameter part,
The structure has an intermediate stage part located between the large diameter part and the small diameter part, the intermediate stage part is provided with the hook part, and the small diameter part is fitted to the axial end of the inner cylinder. It is preferable that

Here, carbon fiber, glass fiber, aramid fiber, alumina fiber, silicon carbide fiber, etc. are used as the fiber material, and the resin to be impregnated into the fiber material includes epoxy resin having thermosetting and adhesive properties,
Polyester resin, polyimide resin, etc. are used. The method for winding the fiber material is as follows:
Examples include a filament winding method using a thread-like fiber material, a tape winding method using a tape-like fiber material, and a hand lay-up method using a woven fiber material.

[Effect]

A plurality of hooks for hooking and guiding the fiber material are provided on the outer peripheral side of the cover, and the resin-impregnated fiber material is wound from the outer peripheral surface of the inner cylinder to the outer peripheral surface of the cover to form the outer cylinder. In some cases, since the fiber material is hooked onto each hook and re-wound, the fiber material can be wound smoothly around the outer circumference of the inner cylinder to form an outer cylinder, and the fiber material may The cover can be reliably prevented from being cut by the fiber material, and the cover can be firmly integrated with the inner cylinder and the outer cylinder by fully utilizing the strength of the fiber material.

[Embodiments] Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 8, taking a hydraulic cylinder tube as an example of a pressure vessel made of a composite material.

1 to 3 show a first embodiment of the invention.

In the figure, reference numeral 21 denotes an inner cylinder made of fiber-reinforced resin material and constituting the inner peripheral side of the tube.
Similarly to 5, thread-like fiber material impregnated with resin is wound at a certain winding angle, for example, close to 90 degrees or about 40 to 85 degrees with respect to the central axis O-O, using a method such as the filament winding method. It is formed into a long cylindrical shape by having one or more wound layers cross-wound with a winding angle until a predetermined thickness is achieved.

Reference numeral 22 denotes a cover fitted to the axial end of the inner cylinder 21 in order to cover the inner cylinder 21;
2 is formed into a bottomed cylindrical shape from a non-ferrous metal material such as aluminum, a ferrous metal material such as stainless steel, or a non-metal material such as a resin material reinforced with short fibers, and is configured to constitute a cylinder cover. It's summery. Here, the cover 22 is located between a large diameter portion 22A on one end in the axial direction, a small diameter portion 22B on the other end, and between the small diameter portion 22B and the large diameter portion 22A.
an intermediate step part 22C formed to have a smaller diameter than the small diameter part 22B and a larger diameter than the small diameter part 22B;
2D, and an oil supply/discharge port 22E radially bored in the large diameter portion 22A so as to communicate with the bottomed hole 22D.
External pressure oil is supplied and discharged from the supply and discharge port 22E.

Further, the intermediate step portion 22C of the cover 22 includes an annular convex portion 22C ₁ and an annular concave portion 22C ₂ formed between the convex portion 22C ₁ and the large diameter portion 22A,
Each small hole 23, which will be described later, is formed on the outer peripheral side of the convex portion _22C1 . Then, the small diameter portion 2 of the cover 22
2B is fitted to the inner periphery of the axial end of the inner cylinder 21, and the axial end face 21A of the inner cylinder 21 is bonded and fixed to the end face of the intermediate step portion 22C using adhesive.
Further, an annular groove 22B ₁ is provided on the outer circumferential side of the small diameter portion 22B.
is formed in the annular groove _22B1 , and an O-ring 27, which will be described later, is mounted together with a back-up spring 28.

23, 23, ... are intermediate step portions 22C of the cover 22
Each small hole 23 is formed as a bottomed hole facing inward in the radial direction in the convex portion 22C ₁ of the intermediate step portion 22C, and the diameter thereof is approximately 2 to 4 mm. The depth is approximately 3 to 8 mm. The small holes 23 are formed at predetermined intervals of, for example, about 4 to 10 mm in the circumferential direction of the convex portion _22C1 . 24, 24, . . . indicate pins that are fitted into the respective small holes 23 and fixed using means such as driving or adhesion, and each of the pins 24 is made of a high-strength member made of a metal material or a non-metal material, e.g. It is formed of a unidirectionally drawn fiber-reinforced resin material, ceramic material, or the like, and its tip side protrudes radially from the outer peripheral surface of the convex portion _22C1 by a predetermined distance, for example, about 15 to 25 mm. The protruding side of each pin 24 constitutes a hook portion for guiding a fiber material 26 to be hooked and rolled back as shown in FIG. 2, which will be described later.

Reference numeral 25 refers to thread-like fiber material 26 impregnated with resin from the outer circumferential surface of the inner cylinder 21 to the middle step part 22 of the cover 22.
C shows an outer cylinder formed by winding the fiber material 26 over the entire surface over the outer peripheral surface, etc., and the outer cylinder 25 is formed by winding the fiber material 26 with respect to the central axis O-O using a method such as a filament winding method. A substantially cylindrical shape is formed by one or more winding layers cross-wound with tension applied to a predetermined thickness so that the winding angle is a constant winding angle close to zero, for example, winding angle θ = 5 to 30 degrees. is formed. 2 and 3, the fiber material 26 is wound in a cross-wound manner, for example, as shown in FIGS. 2 and 3.
The projecting side of the pin or multiple pins 24 is hooked and wound back, and the wound part 25A is attached to the axial end of the outer cylinder 25.
The cover 22 is firmly integrated with the axial ends of the inner tube 21 and the outer tube 25 by the rolled-up portion 25A. In addition, the rewinding portion 25
The fiber material 26 forming A is wound around the outer periphery of the recess 22C ₂ so as to fill the recess 22C ₂ side of the intermediate step 22C on its lower layer side. After winding the fibrous material 26 around the pin 24 as described above,
The pin 24 cuts off the portion of the fiber material 26 that protrudes beyond the laminated thickness (eg, 2 mm to 5 mm).

Here, the fiber material 26 is carbon fiber, glass fiber, aramid fiber, alumina fiber, silicon carbide fiber, or the like, and the resin impregnated into the fiber material 26 includes an epoxy resin having thermosetting and adhesive properties, Polyester resin, polyimide resin, etc. are used. Note that the same material may be used for the inner cylinder 21 as well. Further, a rod cover (not shown) or the like is provided on the axial end side of the inner cylinder 21, and this rod cover is also provided with pins similar to each pin 24 in order to hook and rewind the fiber material 26. . The outer cylinder 25 made of a filamentous fiber material 26 impregnated with resin connects the outer peripheral surface of the rod cover provided at both ends of the inner cylinder 21 in the axial direction, the intermediate step 22C of the cover 22, etc., and the outer peripheral surface of the inner cylinder 21. It is designed to cover them and firmly integrate them.

Furthermore, 27 indicates an O-ring installed in the annular groove 22B ₁ of the cover 22 together with a back-up spring 28, and each O-ring 27 fits the small diameter portion 22B of the cover 22 into the axial end of the inner cylinder 21. Prior to this, the back-up spring 28 is installed in the annular groove _22B1 . The O-ring 27 is connected to the inner circumferential surface of the axial end of the inner cylinder 21 and the cover 22.
A seal is formed between the tube and the outer peripheral surface of the small diameter portion 22B to prevent the pressure oil inside the tube from leaking to the outside. Also, Backup Spring 28
is formed by a thin plate-like ring, etc., and the cover 2
When fitting the small diameter portion 22B of No. 2 into the inner cylinder 21, the O-ring 27 is prevented from protruding from the annular groove _22B1 .

The hydraulic cylinder tube according to this embodiment has the above-mentioned configuration, and a method for manufacturing the same will be described next.

First, a mold material such as a mandrel (not shown) having an outer diameter corresponding to the inner diameter of the tube and whose outer circumferential surface is finished with a predetermined surface accuracy is prepared. While applying a tensile force to the outer circumferential surface of the shape material, resin-impregnated thread-like fiber material is cross-wound using a filament winding method at a constant winding angle until a predetermined thickness is achieved. In this case, the winding angle of the fiber material is 90 with respect to the central axis O-O.
By setting the winding angle to approximately 40 to 85 degrees, for example, the pressure resistance of the tube against internal pressure can be greatly improved. Then, in this state, the fiber material is placed in a curing furnace (not shown) to heat cure the resin impregnated into the fiber material, and the mold material is pulled out to form the inner cylinder 21. Note that in this state, the inner cylinder 21
The outer circumferential surface of the outer cylinder 25 may be suitably machined, and the surface may be roughened with sandpaper or the like to improve the adhesion of the outer cylinder 25 and to remove thermal strain.

Next, the rod cover and the cover 22 with the pins 24 implanted therein are fitted to both ends of the inner cylinder 21 in the axial direction as illustrated in FIG. 1, and fixed with adhesive or the like.

Next, when this adhesive is completely cured, a thread-like fiber material impregnated with resin is applied to the outer circumferential surface of the cover 22 and the like located on both ends of the inner tube 21 and the outer circumferential surface of the inner tube 21. 26 is wound at a predetermined winding angle θ using means such as a filament winding method to form the outer cylinder 25. At this time, the fiber material 26 is stretched with a predetermined tension through the outer circumferential surface of the inner tube 21 toward the outer circumferential surfaces of the covers 22 and the like on both ends, and is hooked onto the protruding side of each pin 24 and re-attached. Roll it back toward the outer peripheral surface of the inner cylinder 21 (see Figure 2).
(see FIG. 3), the cover 22 and the rod cover are firmly integrated with the inner cylinder 21.
Further, by setting the winding angle θ of the fiber material 26 to be close to zero degrees with respect to the central axis OO, for example, θ=5 to 30 degrees, the bending strength, tensile strength, etc. can be significantly increased.

When the outer cylinder 25 having a predetermined thickness is formed on the outer peripheral surface of the inner cylinder 21 and cover 22, etc., these are placed in a curing furnace, and the resin impregnated into the fiber material 26 is thermally cured. . Thus, the tube is molded to have predetermined inner and outer diameters, but if the outer circumferential surface of the outer cylinder 25 is machined using a grinder or the like, the outer circumferential surface of the tube can be finished even more smoothly.

According to this embodiment, when forming the outer cylinder 25 by winding the thread-like fiber material 26 impregnated with resin around the outer peripheral surfaces of the inner cylinder 21, cover 22, etc., the fiber material 26 is hooked onto the protruding side of each pin 24 and wound back, so that the fiber material 26 can be wound regularly and smoothly, and the strength of the fiber material 26 can be fully utilized. The cylinder 21 and the cover 22, etc. can be firmly integrated by the outer cylinder 25, and the cover 22, etc. can be reliably prevented from coming off from the outer cylinder 25, etc., and at the same time, rotation can be surely prevented. I can do it. Then, it becomes possible to calculate the strength of the tube in advance.

Further, the fiber material 26 is not cut in the middle as in the prior art, and the fiber material 26 is
Since the strength of the material can be fully utilized, fatigue resistance and impact resistance can be greatly improved.
A highly reliable and lightweight hydraulic cylinder tube can be obtained. Further, pressure resistance, bending strength, etc. can be improved, and the entire wall thickness of the tube can be reduced.

Furthermore, since the inner cylinder 21, cover 22, etc. can be formed from different materials, it is possible to select appropriate materials. For example, the inner cylinder 21, which requires strength, can be made of fiber reinforced resin material. Cover 2 that requires high hardness in areas such as the outlet 22E
Carbon steel or the like can be used for the second grade, and various effects can be achieved, such as making limit design possible.

Next, FIGS. 4 to 7 show a second embodiment of the present invention. In this embodiment, the same components as in the first embodiment are designated by the same reference numerals, and their explanations are omitted. It shall be.

However, the feature of this embodiment is that an annular mounting groove 31C ₃ is provided around the intermediate step portion 31C of the cover 31, and is located between the annular protrusion 31C ₁ and the recess 31C ₂ .
A two-part hook member 32, ₃ is attached to the mounting groove 31C3.
2 are fitted and fixed from the radial direction.

Here, the cover 31 is formed in the same manner as the cover ₂₂ described in the first embodiment except for the mounting groove 31C3, and includes a large diameter portion 31A, a small diameter portion 31B, an intermediate step portion 31C, a bottomed hole 31D, and an oil Liquid supply/discharge port 31E
The small diameter portion 31B has an annular groove _31B1 ,
The intermediate step portion 31C is provided with a convex portion 31C ₁ and a concave portion 31C ₂ . In addition, each hook member 3 divided into two
2 is the mounting groove 3 of the cover 31 as shown in FIG.
A fitting portion 32A is formed into a semicircular ring shape to fit into the recess _31C3 , and the outer circumferential surface thereof is disposed on substantially the same plane as the outer circumferential surface of the recess _31C2 ; Protrusions 32B, 32B, which serve as hook portions, protrude radially from the outer peripheral side of the portion 32A and are formed at predetermined intervals in the circumferential direction, respectively.
..., and the cross-sectional shape of each projection 32B is square or rectangular as shown in FIG.

The fitting portion 32A of each hook member 32 is fitted into the mounting groove _31C3 from the radial direction,
It is fixed using an appropriate adhesive or the like. At this time,
Each fitting portion 32A surrounds the mounting groove 31C ₃ like a single ring, and each projection 32B extends radially from the outer peripheral surface of the convex portion 31C ₁ , for example, 15 The fiber material 26 is made to protrude by about 25 mm, and after being wound, the fiber material 26 is cut to the laminated thickness. It should be noted that each of the hook members 32 can be easily formed by using casting, pressing, or the like. Further, each protrusion 32B corresponds to each pin 2 described in the first embodiment.
Similar to 4, they may be provided at intervals of about 4 to 10 mm.

Furthermore, 33 is a fiber material 26 impregnated with resin.
The outer cylinder 33 is formed by winding the outer peripheral surface of the inner cylinder 21 and the intermediate step portion 31C of the cover 31, and the outer cylinder 33 is similar to the outer cylinder 2 described in the first embodiment.
The fiber material 2 is formed on each protrusion 32B of each hook member 32 on both ends in the axial direction.
A rewinding portion 33A (only one of which is shown) is provided by hooking and rewinding the reel 6.

Thus, in this embodiment configured in this way, it is possible to obtain almost the same effects as in the first embodiment, but in particular, in this embodiment, each hook member 32 is integrated with a large number of protrusions 32B. After the molding, each hook member 32 is inserted into the mounting groove 31 of the cover 31.
By simply fixing them to C ₃ , a large number of protrusions 32B can be attached to the cover 31 at the same time, and work efficiency can be greatly improved.

In addition, in the second embodiment, each hook member 3
Although each protrusion 32B of No. 2 has been described as having a square or rectangular cross-sectional shape, the cross-sectional shape of each protrusion 32B is not limited to this, and may be circular, for example, as in the modified example shown in FIG. It may be formed into a shape.

Further, in each of the above embodiments, the pin 24 as a hook portion or the protrusion 32B of the hook member 32 is formed separately from the cover 22 or 31. Of course, the hook portion may be formed integrally.

Furthermore, in each of the embodiments described above, the inner tube 21 and the outer tubes 25, 33 were formed using means such as filament winding. It may be formed using means such as a method.
Further, the inner cylinder 21 may be formed of a pipe material made of a ferrous material such as stainless steel or a non-ferrous material such as aluminum, or a resin material reinforced with short fibers. You may.

Further, in each of the above embodiments, a tube for a hydraulic cylinder is used as an example, but the present invention is not limited thereto. It can be applied to various pressure vessels such as , bladder type accumulators, etc.

〔Effect of the invention〕

As detailed above, according to the present invention, a plurality of hooks are provided on the outer peripheral side of the cover fitted to the axial end of the inner cylinder, and a fiber material impregnated with resin is applied to each of the hooks. Since the outer cylinder is formed by hooking it onto the inner cylinder and winding it around the outer circumferential surface of the inner cylinder,
The fiber material can be wound smoothly around the outer circumferential surface of the inner cylinder, allowing the outer cylinder to be formed efficiently, and the cover can be firmly integrated with the outer cylinder and inner cylinder by fully utilizing the strength of the fiber material. It is possible to significantly improve pressure resistance performance, etc. Further, the fatigue resistance, impact resistance, etc. of the pressure vessel can be significantly improved, and the reliability can be improved.

[Brief explanation of drawings]

1 to 3 show a first embodiment of the present invention, in which FIG. 1 is a vertical sectional view of a main part of a hydraulic cylinder tube, FIG. 2 is an explanatory external view of FIG. 1, and FIG. FIG. 2 is an enlarged sectional view in the direction of the - arrow, FIGS. 4 to 7 show the second embodiment, FIG. 4 is a vertical sectional view of the main part of the tube, and FIG. 5 is a half cross section showing the cover. 6 is a front view of the hooking member, FIG. 7 is a sectional view in the direction of the − arrow in FIG. 6, FIG. 8 is a sectional view similar to FIG. 7 showing a modified example of the protrusion, and FIG. The figure is a longitudinal cross-sectional view of a main part of a tube showing a conventional technique, and FIG. 10 is a longitudinal cross-sectional view of a main part of a tube showing another conventional technique. 21...Inner cylinder, 22, 31...Cover, 22A, 3
1A...Large diameter part, 22B, 31B...Small diameter part, 22
C, 31C...Middle stage part, 23...Small hole, 24...Pin (hanging part), 25, 33...Outer cylinder, 25A, 33A
...Rewinding portion, 26...Fiber material, 32...Hooking member, 32B...Protrusion.

Claims (1)

[Scope of Claims] 1. An inner cylinder, a cover that is fitted to an axial end of the inner cylinder and closes the axial end of the inner cylinder, and a plurality of covers provided on the outer circumferential side of the cover, each of which contains fibers. A hook portion for hooking and guiding the material, and a fiber material impregnated with resin is hooked onto each hook portion and wound from the outer circumferential surface of the inner cylinder to the outer circumferential surface of the cover while being wound. A pressure vessel made of a composite material, comprising an outer cylinder formed by 2. The cover has a large diameter part, a small diameter part, and an intermediate stage part located between the large diameter part and the small diameter part, the intermediate stage part is provided with the hook part, and the small diameter part is connected to the inner part. The composite material pressure vessel according to claim 1, which is fitted into an axial end of a cylinder.