JP2961320B2 - Manufacturing method of cylinder tube made of fiber reinforced resin - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a cylinder tube made of fiber reinforced resin used for a hydraulic cylinder, a pneumatic cylinder, a servo valve, a valve, and the like.

[Conventional technology]

Conventional metal cylinder tubes are excellent in durability and slidability, but have a problem that they are heavy, and cylinder tubes made of fiber-reinforced resin aiming at weight reduction have been proposed.

However, in the case of a cylinder tube made of fiber-reinforced resin alone, the resin strength and the elongation at break are small compared to the fiber strength. Failure to maintain, resulting in low pressure resistance strength, leading to leakage breakage.Furthermore, fiber reinforced resin alone is inferior to metal made in terms of frictional resistance and abrasion as sliding properties on the inner circumference. There were drawbacks.

Therefore, a cylinder having a structure in which a metallic inner cylinder is fitted in a fiber-reinforced resin cylinder, instead of a fiber-reinforced resin alone, has been developed as disclosed in, for example, Japanese Patent Application Laid-Open No. 62-288703.

However, in the cylinder tube composed of the metal inner cylinder and the fiber-reinforced resin cylinder, a gap is formed at the joint between the metal inner cylinder and the fiber-reinforced resin cylinder, and the deformation of the metal inner cylinder when an internal pressure is applied. However, it was confirmed that there was a problem that increased by the amount of the voids and durability (fatigue properties) was reduced.

That is, when a fiber-reinforced resin cylinder is molded directly on a metal inner cylinder in a fiber orientation in consideration of the strength balance, a gap is inevitably formed between the two members due to thermal contraction of the fiber and curing contraction of the resin. The inner diameter of the fiber-reinforced resin cylinder is larger than the outer diameter of the inner cylinder.)

It has also been proposed to inject an adhesive into the resulting gap or to re-bond the two members again by means of a secondary adhesive bond,
Due to the low rigidity of the adhesive, deformation of the metal inner cylinder was not avoided.

[Problems to be solved by the invention]

The present invention provides a lightweight and inferior sliding characteristic, in which there is no gap at the joint between the metal inner cylinder and the fiber-reinforced resin cylinder as described above, and the internal pressure load sharing amount of the metal inner cylinder is reduced. It is an object of the present invention to provide a method of manufacturing a cylinder tube made of a fiber-reinforced resin while leaving a preload (circumferential compressive stress) for reducing the pressure.

[Means for solving the problem]

 The gist of the present invention will be described with reference to the accompanying drawings.

A thin, airtight and slidable metal inner cylinder 1 is integrally fixed to a fiber-reinforced resin middle cylinder 2 reinforced with a fiber material by cold-fitting, shrink-fitting, or mechanical press-fitting technique. A flange fitting portion 3 and a flange receiving step portion 4 are formed by cutting processing near both ends of the reinforced resin middle cylinder 2, and a pin erected bulging portion 6 in which a guide pin 5 is implanted is formed near the end. And a flange tube 8 provided with an engaging groove 7 for reinforcing fiber in the middle portion is fitted on the flange fitting portion 3 in a state where the pin erected bulging portion 6 is supported by the flange receiving step portion 4, The guide pin 5 is used between both ends of the fiber-reinforced resin middle cylinder 2, and the fiber material impregnated with the synthetic resin is buried in the reinforcing fiber locking groove 7 formed at both ends. The fiber material is laminated and cured by winding and laminating the fibrous material. The fiber-reinforced resin outer cylinder 9 on the outside of the manufacturing in the cylinder 2 relate to the preparation of fiber-reinforced plastic cylinder tube, characterized in that integrally formed.

[Action and Examples]

A fiber-reinforced resin middle cylinder 2 is formed by hoop winding (rolling at 85 to 90 ° C.) using a highly elastic carbon fiber and an epoxy resin by a known filament winding method.

Next, the outer peripheral surface of the fiber-reinforced resin middle cylinder 2 is cut to form a flange fitting portion 3 and a flange receiving step portion 4,
In addition, the outer peripheral surface of the fiber-reinforced resin middle cylinder 2 is roughened by cutting in order to enhance the adhesion to the fiber-reinforced resin outer cylinder 9.

Next, the metal inner cylinder 1 made of cast iron, steel pipe or aluminum is formed as thin as possible.
In consideration of the design specifications, workability, and the measured value of the inner diameter of the fiber-reinforced resin inner cylinder 2, an appropriate cold-fitting white is determined and processed.

When the metal inner cylinder 1 is formed, if a load is applied in advance so that a preload (initial compressive stress) remains in the circumferential direction, the cylinder tube according to the present invention is used, and when an internal pressure load is applied. The generated tensile stress is reduced, and the fatigue resistance is improved.

Subsequently, after cooling and shrinking the metal inner cylinder 1 using liquid nitrogen, the metal inner cylinder 1 is inserted and fixed in the fiber-reinforced resin middle cylinder 2, and the aluminum flange cylinder 8 is further formed of the fiber-reinforced resin. A guide pin 5 is attached to and fixed to both end portions of the outer peripheral surface of the middle cylinder 2 at the pin erected bulging portion 6 of the flange cylinder 8 with an epoxy adhesive.

When the shrink fitting means is used instead of the cold fitting means, on the contrary, the fiber reinforced resin middle cylinder 2 is fitted to the fiber reinforced resin middle cylinder 2 in a heated state.

In this way, when the cold or shrink fitting means is used, the joining between the fiber-reinforced resin inner cylinder 2 and the metal inner cylinder 1 is performed more firmly.

When the metal inner cylinder 1 is inserted into the fiber-reinforced resin inner cylinder 2 and fixed thereto simply by a mechanical press-fitting method, it is necessary to consider a certain tightening margin.

Next, a helical winding (± 30 degree winding) is applied to the outer peripheral surface of the fiber-reinforced resin middle cylinder 2 using a high-strength carbon fiber and an epoxy resin by a filament winding method to obtain an axial strength.
To form the outer cylinder 9 made of fiber reinforced resin.

This fiber-reinforced resin outer cylinder 2 is formed by connecting continuous carbon fibers impregnated with epoxy resin to guide pins 5 erected near both ends of the fiber-reinforced resin middle cylinder 2 as shown in FIG. The carbon fiber is dropped into the reinforcing fiber locking groove 7 formed in the pin erected bulging portion 6 while entangled with the carbon fiber.

Therefore, the flange cylinder 8 is firmly attached to the fiber-reinforced resin middle cylinder 2 by molding the fiber-reinforced resin outer cylinder 9.

The fiber reinforced resin cylinder is manufactured by the above steps.

The fiber material used in the present invention includes, in addition to carbon fiber, glass fiber, aramid fiber, alumina fiber, silicon carbide fiber, vinylon fiber, nylon fiber, polyethylene fiber, ceramic fiber, etc., and synthetic resin used with the fiber material. In addition to the epoxy resin, there are a polyisid resin, a polyester resin, and the like having thermosetting properties and adhesiveness.

As the means for forming the fiber-reinforced resin inner cylinder 2 and the fiber-reinforced resin outer cylinder 9 of the present invention, a tape-shaped fiber material or a woven fiber material may be used in addition to a filament winding method (FW method) using a fiber material. Alternatively, a tape winding method (TW method) may be used.

Furthermore, the fiber orientation winding angle of the fiber-reinforced resin middle cylinder 2 is selected within the range of ± 50 to 90 ° C. and the fiber orientation winding angle of the fiber-reinforced resin outer cylinder 9 ± 10 to 60 ° C. Depending on the required conditions, the inner cylinder and the outer cylinder may have a plurality of winding configurations.

 Reference numeral 10 in the figure is a bolt hole.

〔The invention's effect〕

As described above, the present invention provides a method of manufacturing a fiber reinforced resin cylinder tube that is lightweight, has high pressure resistance, and is excellent in sliding characteristics and fatigue resistance.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 shows a state in which a metal inner cylinder is fitted with a fiber-reinforced resin middle cylinder, and a flange cylinder is fitted on both ends. FIG. 2 is a perspective view showing a state before a reinforced resin outer cylinder is formed on the outer peripheral surface of a fiber reinforced resin middle cylinder. FIG. 2 is a partial cutaway view of a main part of a fiber reinforced resin cylinder manufactured according to the present invention. FIG. 3 is a cross-sectional view and FIG. 3 is an explanatory diagram relating to molding of a fiber-reinforced resin outer cylinder. 1 ... Metal inner cylinder, 2 ... Middle cylinder made of fiber reinforced resin, 3 ...
Flange fitting part, 4 ... Flange receiving step part, 5 ... Guide pin, 6 ... Pin erected bulging part, 7 ... Lock groove for reinforcing fiber, 8 ... Flange cylinder, 9 ... Fiber Reinforced resin outer cylinder.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification code FI B29L 9:00 23:00 (72) Inventor Hisamoto Hashimoto 2-6-2 Otemachi, Chiyoda-ku, Tokyo Hitachi Construction Machinery Co., Ltd. (72) Inventor Morio Tamura 2-6-2 Otemachi, Chiyoda-ku, Tokyo Hitachi Construction Machinery Co., Ltd. (56) References JP-A-64-26064 (JP, A) JP-A-63-249628 (JP) , A) (58) Field surveyed (Int. Cl. ⁶ , DB name) B29C 70/04-70/24

Claims (1)

(57) [Claims] 1. A thin metal inner cylinder having good airtightness and sliding properties is integrally inserted into a fiber-reinforced resin inner cylinder reinforced with a fiber material by cold-fitting, shrink-fitting or mechanical press-fitting. A flange fitting portion and a flange receiving step portion are formed by cutting work near both ends of the fiber-reinforced resin middle cylinder, and a pin standing bulging portion having a guide pin planted near the end is formed, And, a flange tube provided with a reinforcing groove for a reinforcing fiber in the middle portion is fitted to the flange fitting portion in a state in which the pin erected bulging portion is supported by the flange receiving step portion, and the fiber reinforced resin middle tube is formed. A fiber material impregnated with a synthetic resin is wound and laminated using a guide pin between both ends and embedded in the reinforcing fiber locking groove formed at both ends, and the wound and laminated fiber material is used. By curing the fiber, the fiber is placed on the outside of the fiber-reinforced resin middle cylinder fitted on the metal inner cylinder. Preparation of fiber-reinforced plastic cylinder tube and forming a resin outer cylinder together.