JPH0511542B2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a fiber-reinforced resin suitable for use in, for example, tubes of hydraulic and pneumatic cylinders, booms or arms for civil engineering and construction machinery, pipe materials for lattice booms of cranes, etc. Regarding a cylindrical body.

[Prior art]

Conventionally, fiber-reinforced resin cylindrical bodies made by winding and molding fiber materials impregnated with adhesive resin are being used more and more because they are lighter and stronger than metal cylindrical bodies. However, when this type of fiber-reinforced resin cylindrical body is used as a pressure vessel, such as a tube for a hydraulic cylinder, the opening on the shaft end side of the tube has conventionally been formed by the method shown in FIG. 5 or 6. It was covered.

In FIG. 5, reference numeral 1 denotes a tube body, which is formed by winding a fiber material impregnated with an adhesive resin into a hollow cylindrical shape. A ring groove 2 is provided around the ring 1A at a position closer to one side in the axial direction.
Reference numeral 3 denotes a cylinder cover that closes the opening at one end of the tube body 1, and the cover 3 is made of a thick disk having an outer diameter that is the same as the inner diameter of the tube body 1.
An O-ring 4 is fitted onto the outer peripheral surface 3A. 5
is a retaining ring made of an annular flat plate fitted into the ring groove 2 to retain the cover 3 in the tube body 1, and the retaining ring 5 is adapted to receive internal pressure applied to the cover 3. .

On the other hand, FIG. 6 shows a tube for a hydraulic cylinder according to another prior art. In the figure, 11 is a tube body molded from fiber-reinforced resin like the tube body 1, and a male screw 1 is located on the outer peripheral surface 11A of the tube body 11 near one shaft end.
2 is formed. Reference numeral 13 denotes a cylinder cover that closes the opening at one end of the tube body 11. The lid cover 13 is formed in the shape of a thick disk with a larger diameter than the tube body 11, and an annular ring groove 14 is provided on the inner surface. It consists of a main body part 13A and a fitting part 13B which is formed in a cylindrical shape and protrudes from the inner surface of the main body part 13A, and has a female thread 15 formed on the inner circumferential surface to be screwed into the male thread 12. The cylinder cover 13 is screwed onto the tube body 11 with an O-ring 16 fitted in a ring groove 14, and receives internal pressure by the screwing force between the male thread 12 and the female thread 15. There is.

[Problem that the invention seeks to solve]

Accordingly, in the conventional technique of receiving the cover 3 using the retaining ring 5 shown in FIG. However, due to this groove machining, tube 1
This results in the fiber material forming the fiber being cut short. As a result, there is a drawback that the strength of the fiber-reinforced resin, which has high strength in the fiber direction, is partially lost. In addition, the tube body 1
is made by winding and forming fiber material,
When the ring groove 2 is formed in the tube body 1, delamination is likely to occur from the groove 2, resulting in a lack of reliability.

As mentioned above, forming the ring groove 2 in the tube body 1, which is formed by winding a resin-impregnated fiber material, causes the tube body 1 to lose its strength. The disadvantage is that it cannot be raised.

On the other hand, as shown in FIG.
Since the fiber material is cut when forming the external thread 12 on the outer circumferential surface 11A of the tube body 11, it has the same drawbacks as the prior art described above.

The present invention has been made in view of the above-mentioned drawbacks of the prior art.The present invention has been made in view of the above-mentioned drawbacks of the prior art. A cylindrical body made of resin is provided.

[Means for solving problems]

The means of the present invention configured to solve the above-mentioned problems includes an inner cylinder formed by winding a resin-impregnated fiber material, and an inner cylinder that is fitted into an axial end of the inner cylinder, and has an outer circumferential surface. a cylindrical mounting member in which at least one engaging portion is formed in the middle in the axial direction; and a fiber material impregnated with resin is integrally formed from the inner cylinder to at least the engaging portion of the mounting member. It consists of an outer cylinder wrapped around the outer cylinder.

Here, the above-mentioned fiber materials include carbon fibers, glass fibers, aramid fibers, alumina fibers, silicon carbide fibers, etc., and the resins to be impregnated into the fiber materials include epoxy resins having adhesive properties, polyester resins,
There are thermosetting resins and thermoplastic resins such as polyimide resins and polyetheretherketone resins.
Further, the method for winding the fiber material includes a filament winding method using a filamentous fiber material;
Examples include a tape winding method using a tape-like fiber material, a hand lay-up method using a woven fiber material, and a rolling table method using a prepreg.

Furthermore, there are mounting members molded from metal materials, ceramic materials, resin materials reinforced with short fibers, and the like.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to FIGS. 1 to 4.

1 to 3 show a first embodiment of the invention. In the figure, 21 is a tube for a hydraulic cylinder, 22 is an inner cylinder constituting the tube 21, and the inner cylinder 22 is made by filament winding of a filamentous fiber material made of carbon fiber impregnated with epoxy resin, which is a thermosetting resin. It is formed into a cylindrical shape consisting of one or more wound layers cross-wound to a predetermined thickness at a constant winding angle close to 90° and θ ₁ =40 to 85°.

Reference numeral 23 indicates a cover mounting member made of a metal cylinder fitted to both axial ends of the inner cylinder 22 (the other end is not shown). The cover attachment member 23 includes a thick cylindrical portion 24A located on one side in the axial direction;
A thin cylindrical portion 24C formed on the other axial side from the thick cylindrical portion 24A via the inclined surface 24B, and a medium cylindrical portion formed on the other axial end side from the thin cylindrical portion 24C via the slanted surface 24D. A cylindrical body 24 consisting of a portion 24E, and a thick cylindrical portion 2 of the cylindrical body 24.
4A is composed of a plurality of male threaded portions 25, 25, . . . bored in the axial direction from one end surface. Thus, an annular engagement recess 26 is formed in the outer circumferential surface 23A of the cover attachment member 23, located midway in the axial direction.

Reference numeral 27 denotes an outer cylinder formed over the entire surface from the outer peripheral surface 22A of the inner cylinder 22 to the outer peripheral surface 23A of the cover attachment member 23. Like the inner cylinder 22, the outer cylinder 27 is made of carbon fiber impregnated with epoxy resin. The filament winding method is used to create a filamentous fiber material with a constant winding angle close to 0°, θ ₂ =5, as shown in Figure 2.
1. Cross-wound at ~20° until the specified thickness is reached.
It is formed into a cylindrical shape consisting of more than one wound layer.

Thus, the tube 21 in this embodiment has an inner tube 22 made of fiber reinforced resin, a cover attachment member 23 made of metal fitted on both sides of the inner tube 22 in the axial direction, and a connection between the inner tube 22 and the cover attachment member 23. outer peripheral surface 22A,
Outer cylinder 2 made of fiber reinforced resin formed on the entire surface of 23A
It consists of 7.

On the other hand, 28 is a metal cylinder cover for closing one axial opening of the tube 21, and the cover 28 includes a thick disc-shaped main body 28A formed to have the same outer diameter as the outer cylinder 27; A flat cylindrical fitting part 28B is located at the center of the inner surface of the main body part 28A and is formed to protrude and fit into the inner cylinder 22.
is located on the outer peripheral side of the fitting portion 28B, and
It is composed of a plurality of bolt insertion holes 28C, 28C, . . . which are spaced apart in the circumferential direction of 8A. In addition, 29 is a cylinder cover 28 and an inner cylinder 22.
The fitting part 28 of the cover 28 to seal between
B O-ring fitted on the outer peripheral surface, 30, 30,...
... are a plurality of bolts for fastening the cylinder cover 28 to the tube 21.

The present embodiment has the above-described configuration, and next, a method for manufacturing the tube 21 according to the embodiment will be explained.

First, a mold material (mandrel) having an outer diameter equal to the inner diameter of the tube 21 to be manufactured and having sufficient surface accuracy is manufactured in advance. Next, in order to form the inner cylinder 22, a filamentous fiber material made of carbon fiber impregnated with epoxy resin is wound at a constant winding angle θ ₁ by a filament winding method while applying a tensile force to the outer peripheral surface of the molded material. Cross-winding is performed to form a cylindrical body consisting of wound layers having a predetermined thickness. In addition, since the inner cylinder 22 receives the most internal pressure in the circumferential direction, the thread-like fiber material has a winding angle θ ₁ =40 to 85°, which is close to the winding angle θ ₁ =90°, which is most suitable for receiving the internal pressure. Wind it with.

After the cylindrical body is formed as described above, it is placed in a curing furnace and the epoxy resin is thermally cured to form the inner cylinder 22. The outer circumferential surface 22A of the inner tube 22 is machined in order to increase the adhesion between the cover attachment member 23 and the outer tube 27 and to eliminate thermal strain of the inner tube 22.

Next, at one end of the inner cylinder 22 in the axial direction,
Cover mounting member 23 with adhesive applied to the inner peripheral surface
Fit and secure.

When the adhesive is completely cured, the inner cylinder 2
2 and each outer peripheral surface 22A of the cover mounting member 23, 2
An outer cylinder 27 is integrally formed on 3A. here,
Similar to the inner cylinder 22, the outer cylinder 27 is made of a filamentous fiber material made of carbon fiber impregnated with epoxy resin at a fixed winding angle θ ₂ from the outer peripheral surface 22A of the inner cylinder 22 to the outer peripheral surface of the cover mounting member 23. The entire surface of 23A, that is, from the medium-walled cylindrical section 24E to the thin-walled cylindrical section 24 on the other side in the axial direction.
Cross-winding is performed by the filament winding method while applying a tensile force to the thick-walled cylindrical portion 24A on one side in the axial direction beyond C to form a cylindrical body consisting of wound layers of a predetermined thickness.

Note that since the outer cylinder 27 is the one that receives the most bending stress in the axial direction, the thread-like fiber material has a winding angle θ ₂ that is most suitable for receiving the bending stress in the axial direction, which is close to θ ₂ =0°. = Wound at 5 to 20 degrees. Furthermore, when winding the filamentous fiber material, by applying epoxy resin to the outer peripheral surface 23A of the cover attachment member 23 in advance, it is possible to prevent a gap from forming between the cover attachment member 23 and the outer cylinder 27. , can increase adhesion.

After forming the wound layer that will become the outer cylinder 27 as described above, the outer cylinder 27 is molded by placing the epoxy resin in a curing furnace and thermally curing the epoxy resin.

After the inner cylinder 22, cover attachment member 23, and outer cylinder 27 are integrally formed as described above, the inner cylinder 2
By pulling out the shape material from the tube 2, a tube 21 with high inner surface precision and sufficient strength against stress in the circumferential direction and the axial direction is completed. After that, by inserting each bolt 30 into each bolt insertion hole 28C of the cylinder cover 28 and screwing it into the female thread 25 of the cover mounting member 23, the cylinder cover 2
8 is fastened to the tube 21.

As described in detail above, according to this embodiment, the inner cylinder 22
A metal cover mounting member 23 having a plurality of internally threaded portions 25, 25, . The outer cylinder 27 is formed by winding the thread-like fiber material up to the thick-walled cylindrical portion 24A through the thick-walled cylinder part 24C, and unlike the prior art, the thread-like fiber material is not subjected to any cutting process. do not have. Therefore, the cover mounting member 2
The tube 21 can be prevented from being destroyed by internal pressure unless the tube 21 is pulled out or the filamentous fiber material is broken by the tensile force.

Further, as mentioned above, since the filamentous fiber material is not cut in the middle, the tube 21 can be designed based on the inherent strength of the fiber, and the inner cylinder 22, outer cylinder 27
Since no grooves are formed in any of the fibers, delamination caused by fiber cutting can be completely prevented.

Furthermore, in this embodiment, the cover mounting member 23 is molded from a metal material, so that the female threaded portion 25 can have sufficient strength. This can improve the liquid tightness of the hydraulic cylinder and improve the reliability of the entire hydraulic cylinder. Note that the cover attachment member 23 may be molded using a ceramic material or a fiber-reinforced resin using short fibers instead of a metal material. Further, the cover mounting member may be formed by hoop winding in which a filamentous fiber material is wound at a winding angle θ ₃ =90°, and when formed by hoop winding, it has the highest pull-out strength with respect to the bolt 30. can be obtained.

In addition, by forming the axial length of the thin cylindrical portion 24C, which receives the most of the tightening force of the outer cylinder 27 in the cover mounting member 23, to be longer than that in the embodiment, the cover mounting member is brought into closer contact with the inner cylinder 22. You can do it like this.

Further, as shown in FIG. 3, the engagement recess 26 located outside the thin cylindrical portion 24C of the cover mounting member 23 is covered with a filamentous fiber material impregnated with resin at a winding angle θ ₄ .
By forming the hoop winding part 31 wound at =90° and tightening the thin cylindrical part 24C from the outer circumferential side, it is possible to increase the adhesion between the cover mounting member 23 and the inner cylinder 22, and moreover, the tensile force due to the internal pressure can be increased. It is possible to further increase the strength against. Further, the filamentous fiber material of the outer cylinder 27 that is wound from the outer circumferential surface 22A of the inner cylinder 22 to the outer circumferential surface 23A of the cover attachment member 23 is wound from the medium-walled cylindrical portion 24E to the thin-walled cylindrical portion 24C of the cover attachment member 23. After that, it may be folded back at the thin cylindrical portion 24C and wound in the direction of the outer circumferential surface 22A of the inner cylinder 22, so as not to be wound around the outer periphery of the thick cylindrical portion 24A.
By doing so, it is possible to prevent the filamentous fiber material from being cut on the axial end side of the tube 21, thereby further increasing the strength of the outer cylinder 27.

Next, FIG. 4 shows a second embodiment of the present invention.
The feature of this embodiment is that the inner cylinder 42 constituting the tube 41 is formed into a hollow rectangular cylinder shape using a prismatic material. The inner cylinder 42 and the outer cylinder 44 formed on the outer periphery of the cover attachment member 43 are also formed into a rectangular shape to form the tube 41 in the shape of a hollow rectangular cylinder.

In this embodiment as well, the inner cylinder 42 and the outer cylinder 44 are formed by a wound layer of a fiber material impregnated with resin, as in the first embodiment, but the cover mounting member 43 is formed as shown in the figure. The rectangular cylinder body may be integrally formed with the inner cylinder 42, or four plates may be attached to the outer surface of the inner cylinder 42, and the plates may be covered with the outer cylinder.

Note that in each of the embodiments described above, the inner cylinders 22, 4
2, cover mounting members 23, 43 and outer cylinder 26,
In the present invention, the mounting member provided between the inner cylinder and the outer cylinder may be a flange-like member, a mounting bracket, or a mounting ring. Further, the pipe according to the present invention is not limited to the cylindrical or rectangular tube shape described in each embodiment, but may have various closed cross-sectional shapes such as an ellipse or a triangle.

〔Effect of the invention〕

Since the present invention is configured as detailed above, it achieves the following effects.

Since the inner cylinder and outer cylinder formed by winding the fiber material are not provided with any ring grooves or thread grooves in the conventional technology for cutting the fiber material,
The cylindrical body can be designed with high safety based on the inherent strength of the fiber material.

As mentioned above, since the fiber material is not cut by the ring groove etc., delamination phenomenon from the cut point can be completely prevented, and the durability of the fiber reinforced resin cylindrical body can be improved. You can improve.

At least one engaging part is provided on the outer periphery of the mounting member in the middle in the axial direction, and the fiber material forming the outer cylinder is wound around the engaging part. can firmly absorb the axial force applied to the mounting member, and can manufacture a fiber-reinforced resin cylindrical body with excellent strength. Therefore, when the outer cylindrical body is used as a pressure vessel like a tube for a hydropneumatic cylinder, its internal pressure can be set high.

As mentioned in the above sections, the fiber-reinforced resin cylindrical body according to the present invention has excellent safety, durability, and strength, which increases the degree of freedom in design and enables limit design. .

[Brief explanation of drawings]

1 to 3 show a first embodiment of the present invention, in which FIG. 1 is a partial vertical sectional view of a tube for a hydraulic cylinder, FIG. 2 is a partial external view of the tube, and FIG.
FIG. 4 is a partial vertical sectional view showing a modification of the tube shown in FIG. 1, FIG. 4 is an external perspective view of the tube according to the second embodiment of the present invention, and FIG. 5 is a hydraulic cylinder according to one prior art. Partial longitudinal sectional view of tube for use, No. 6
The figure is a partial vertical sectional view of a tube for a hydraulic cylinder according to another conventional technique. 22, 42... Inner cylinder, 23, 43... Cover attachment member, 26... Engagement recess, 27, 44... Outer cylinder.

Claims (1)

[Claims] 1. An inner tube formed by winding and molding a fiber material impregnated with resin, which is fitted into the axial end of the inner tube, and has at least one engaging portion formed on the outer circumferential surface located midway in the axial direction. An outer cylinder made of fiber-reinforced resin, comprising a cylindrical mounting member, and an outer cylinder formed by integrally wrapping a resin-impregnated fiber material from the inner cylinder to at least the engaging portion of the mounting member. Cylindrical body.