JPH054525B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cylinder device used as a hydraulic cylinder or a pneumatic cylinder.

[Prior art]

Conventionally, a cylinder device used as a hydraulic cylinder or a pneumatic cylinder has a tube with both ends covered, a piston that is slidably provided in the tube and defines the inside of the tube into two chambers, and A piston rod is fixed to the piston and the other end protrudes outside the tube, and when fluid is supplied to and discharged from each chamber, the stress in the axial and circumferential directions that the tube receives due to the fluid is People started to accept it because of its thickness.

As such conventional cylinder devices, those shown in FIGS. 4 and 5 are known.

That is, in the drawings, 1 is a tube made of a metal cylinder, for example, and both ends of the tube 1 are covered with a head cover 2 and a rod cover 3, and the head cover 2 and rod cover 3 are provided with supply/discharge ports 4 and 5, respectively. is formed. A piston 6 is slidably inserted into the tube 1, and the piston 6 defines the inside of the tube 1 into two chambers A and B. 7 is a piston rod, one end of which is fixed to the piston 6, and the other end protrudes from the rod cover 3 to the outside.

Then, when fluid is supplied to one of the supply and discharge ports 4 and 5, the pressure in the chamber A becomes high, the piston 6 is displaced to the left in the figure, and the fluid in the chamber B is supplied to the supply and discharge port 4. is discharged from the supply/discharge port 5.
When fluid is supplied to the piston 6, the piston 6 is displaced to the right in the figure, and at this time, the pressure in the chamber on the high pressure side is determined by the load.

[Problem that the invention seeks to solve]

However, in the cylinder device according to the prior art described above, since the tube 1 is constructed as a metal cylindrical body, there are the following problems.

That is, according to the thin-walled cylinder theory, the axial stress generated in the tube 1 due to the fluid pressure in chambers A and B is σ _l ,
If the circumferential stress is σ _r , the axial stress σ _l is 1/2 of the circumferential stress σ _r .

As a result, firstly, when designing the tube 1, it must be designed based on the circumferential stress σ _r , which has the disadvantage of over-designing in the axial direction. Second, when aiming to increase the pressure of the cylinder device, the thickness of the tube 1 should be
It must be increased according to the circumferential stress σ _r . For this reason, the wall thickness of the tube 1 becomes large based on the circumferential stress σ _r , and there is a drawback that the weight of the entire cylinder device becomes large. Thirdly,
The iron-based material constituting the tube 1 has the disadvantage of poor vibration damping properties and poor shock absorption properties.

The present invention was made in view of the above-mentioned drawbacks of the prior art, and the present invention ensures desired strength by forming a tube with two inner and outer wound layers made of fiber material impregnated with resin. The cylinder device is designed to not only significantly reduce weight but also strengthen the interface between the inner and outer layers, giving the entire tube excellent shock absorption and fatigue resistance. is intended to provide.

[Means for solving problems]

The feature of the configuration adopted by the present invention in order to solve the above-mentioned problems is that the tube of the cylinder device is
It consists of two wound layers formed by winding and thermosetting a resin-impregnated fiber material with different winding angles on the inner layer side and the outer layer side, and the inner layer side of each wound layer is Increase the winding angle of the fiber material,
The reason for the outer layer is that the winding angle of the fiber material is made small.

Specific examples of the fiber material impregnated with the resin include a thread-like fiber material wound by a filament winding method, and a tape-like or woven fiber material wound by a tape winding method.

[Effect]

With the above configuration, of the two wound layers, the inner layer side where the fiber material has a larger winding angle can receive the fluid pressure (internal pressure) inside the tube and improve the strength against stress in the circumferential direction. The outer layer side, which has small corners, can absorb the bending load, etc. that acts on the tube from the outside, and can improve the strength against stress in the axial direction. Furthermore, when each of the wound layers constituting the tube is heat-cured and then slowly cooled, the outer layer side with a smaller winding angle will shrink more than the inner layer side with a larger winding angle, so the outer layer side can be tightly adhered to the inner layer side. , it is possible to strengthen the interface between the two.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail based on FIGS. 1 to 3. Note that the same reference numerals are given to the same components as those of the prior art described above, and the explanation thereof will be omitted.

11 in the figure is a cylindrical tube according to this embodiment, and the tube 11 is made by intersecting a filamentous fiber material 12 impregnated with a thermosetting resin by a predetermined thickness at a constant angle by a filament winding method. It consists of two layers, an inner layer side 11A and an outer layer side 11B, which are wound and formed into a cylindrical shape.

Moreover _, in the tube 11 of this embodiment, as shown in FIG.
It is set at 70°, and the outer layer side 11B is set to the inner layer side 1
1A, the winding angle θ ₂ =20°, for example, so that the winding angle θ ₂ =0° is close to 0°. Thus,
The entire tube 11 is integrally formed of a thread-like fiber material 12, and the winding angles θ ₁ and θ ₂ of the thread-like fiber material 12 are different between the inner layer side 11A and the outer layer side 11B.
As a result, the tube 11 is formed in two layers. Here, as the thread-like fiber material 12, for example, carbon fiber, aramid fiber, glass fiber, etc. are used, and as the resin impregnated into the thread-like fiber material 12, thermosetting resin such as polyimide resin, epoxy resin, etc. and a resin having adhesive properties are used.

Note that 13 in the figure is a cylinder head, and the cylinder head 13 and the tube 11 are connected by bolts 14.
It is fixed through. 15 is an O-ring interposed between the cylinder head 13 and the tube 11.

Although the cylinder device of the embodiment has the above-described structure, a method of manufacturing the tube 11 using the filament winding method will be described next.

First, the filamentous fiber material 12 impregnated with a thermosetting resin is wound around the outer periphery of a cylindrical material under tension at a winding angle of, for example, θ ₁ =70°, until the thickness reaches half of the thickness of the tube 11. The inner layer side 11A is formed by cross-winding up to 100 degrees. Next, the filamentous fiber material 12 is cross-wound around the outside of the inner layer side 11A at a winding angle θ ₂ =20°, for example, to form the outer layer side 11B.

The filamentous fiber material 12, which has been wound to form a cylindrical body as described above, is placed into a curing furnace while being wound around a cylindrical shape, and the thermosetting resin impregnated in the filamentous fiber material 12 is cured. Ru. Thereafter, the hollow cylindrical tube 11 is manufactured by removing the cylindrical shape material from the cylindrical body.

By the way, the winding angles θ ₁ and θ ₂ of the filamentous fiber material 12 forming the tube 11, the strength F against internal pressure in the circumferential direction and the strength (Young's modulus) E in the axial direction of the tube 11 are as shown in FIG. Therefore, the winding angle θ ₁ ,
By changing θ ₂ , these intensities F and E can be set appropriately.

Therefore, in this embodiment, the inner layer side 11A of the tube 11 has a winding angle of θ ₁ =70°, which is close to the value θ=90°, which is the most suitable value for receiving internal pressure in the circumferential direction.
By winding the filamentous fiber material 12 on the outer layer side 11B at a winding angle θ ₂ =20°, which is close to the optimal winding angle θ ₂ =0° for receiving the bending stress in the axial direction, the tube is formed. Inner layer side 1 that directly receives the fluid pressure (internal pressure) of 11
1A can effectively improve the strength against stress in the circumferential direction, and the outer layer side 11B, which receives bending loads etc. acting on the tube 11 from the outside, can effectively improve the strength against stress in the axial direction.

As a result, the tube 11 can be given strength in two directions corresponding to stress in the circumferential direction and stress in the axial direction, respectively, with a minimum number of windings. In addition, since the tube 11 is entirely formed from a filamentous fiber material 12 impregnated with resin, which has a lower specific gravity than metal materials, its weight is significantly reduced while having strength equal to or greater than that made by conventional technology. be able to.

Further, the filamentous fiber material 12 made of carbon fiber, glass fiber, etc. has a small coefficient of thermal expansion (actually, it is a negative value), and the polyimide resin, epoxy resin, etc. with which the filamentous fiber material 12 is impregnated has a large coefficient of thermal expansion. Therefore, in the inner layer side 11A where the filamentous fiber material 12 extends in the circumferential direction with a winding angle θ ₁ =70°, the shrinkage in the circumferential direction during slow cooling after thermosetting is caused by the filamentous fiber material 12 extending in the circumferential direction. On the other hand, on the outer layer side 11B where the filamentous fiber material 12 extends in the axial direction with a winding angle θ ₂ =20°, the resin impregnated in the filamentous fiber material 12 mainly contracts in the circumferential direction, and the outer layer The side 11B is greatly shrunk (diameter reduced) in the circumferential direction with respect to the inner layer side 11A, so that the adhesion strength between the two can be increased during slow cooling after thermosetting, and the interface between the two can be made very strong.

On the inner layer side 11A, the filamentous fiber material 12 extends in the circumferential direction with a large winding angle θ ₁ .
The thread-like fiber material 12 is easily lined up on the inner surface of the tube 11, and the dimensional accuracy of the inner surface can be improved, and the stress (internal pressure) in the circumferential direction can be reliably received by the thread-like fiber material 12 extending in the circumferential direction. By reducing the load on the resin, oil leakage due to resin cracks, etc. can be minimized.

Furthermore, as described above, the inner layer side 11A of the tube 11
By appropriately selecting the winding angles θ ₁ and θ ₂ of the outer layer side 11B, strength can be imparted to the tube 11 separately on the inner layer side 11A and the outer layer side 11B in response to stress in the circumferential direction and the axial direction. Therefore, the degree of freedom in design including the wall thickness of the tube 11 can be increased, and the problem of excessive design with respect to axial stress described in the thin-walled cylinder theory can also be solved. Furthermore, the filamentous fiber material 12 impregnated with resin has better shock absorption and fatigue resistance than iron-based materials, so that a high-quality cylinder device can be manufactured.

In this embodiment, the winding angles θ ₁ and θ ₂ of the filamentous fiber material 12 are the inner layer side 11A and the outer layer side 1 of the tube 11.
Set it so that it is clearly different from 1B, and
Although the filamentous fiber material 12 is configured to be formed in two layers, the filamentous fiber material 12 may be wound while continuously changing the winding angles θ ₁ and θ ₂ from the inner layer side 11A to the outer layer side 11B. With this configuration, the mechanical properties of the tube 11 with respect to stress in the circumferential direction and the axial direction can be gradually changed. Further, in the embodiment, the tube 11 is made of a single filamentous fiber material 12.
However, for example, the inner layer side 11A of the tube 11 may be wound with inexpensive glass fiber, and the outer layer side 11A, which receives axial stress, may be wound with high-tensile carbon fiber. By using a combination of different types of filamentous fiber materials with different characteristics, an inexpensive and lightweight cylinder device can be manufactured.

Furthermore, in the embodiment, the filament winding method using the filamentous fiber material 12 was exemplified as a method for forming the tube 11, but a tape using a tape-like or woven fabric-like fiber material instead of the filamentous fiber material 12 was used. It may also be formed by a winding method. Although the bolts 14 are used to join the tube 11 and the cylinder head 13, an adhesive may also be used in combination.

〔Effect of the invention〕

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

Since the tube of the cylinder device is made of a fiber material impregnated with resin in a smaller proportion than metal material, the weight of the cylinder device can be significantly reduced compared to the prior art.

The inner layer of the tube is formed of a wound layer of fiber material with a large winding angle to absorb internal pressure in the circumferential direction, and the outer layer is formed of a winding layer of fiber material with a small winding angle to absorb stress in the axial direction. Since the tube is formed with two layers of winding layers, the number of windings of the fiber material is minimized, and the tube can have strength corresponding to stress in the circumferential direction and the axial direction, respectively.
The wall thickness of the tube can be reduced.

The outer layer side, where the fiber material extends in the axial direction with a small winding angle, contracts (diameter reduction) more than the inner layer side during slow cooling after thermosetting due to the resin impregnated into the fiber material. The tube can be brought into close contact with both sides, making the interface between the two strong and improving the reliability of the tube.

On the inner layer side where the fiber material extends in the circumferential direction with a large winding angle, the fiber material is easier to line up on the inner layer side, improving the dimensional accuracy of the inner surface, and the fiber material absorbs the stress in the circumferential direction. It can reduce the burden on the body and effectively prevent oil leakage due to damage to the resin.

Since the winding angle and number of windings of the fiber material can be set appropriately, the degree of freedom in design can be increased, limit design is possible, and a tube with desired strength can be manufactured.

Since the tube is molded from a fiber material that has better shock absorption and fatigue resistance than metal materials, it is possible to improve the durability and reliability of the cylinder device.

[Brief explanation of drawings]

Figures 1 to 3 relate to one embodiment of the present invention, where Figure 1 is an enlarged sectional view of the main part showing the cylinder device, and Figure 2A is the inner layer side of the tube formed by the filament winding method. An explanatory diagram showing the tube, B is an explanatory diagram showing the outer layer side of the tube,
Fig. 3 is a characteristic diagram showing the internal pressure and axial strength with respect to the winding angle, Figs. 4 and 5 relate to the prior art, Fig. 4 is a longitudinal cross-sectional view of the cylinder device, and Fig. 5 is the graph shown in Fig. 4. It is an enlarged sectional view of the main part inside. 6...Piston, 11...Tube, 11A...
...Inner layer side, 11B...Outer layer side, 12...Fibre material.

Claims (1)

[Claims] 1. A cylinder device in which a piston is slidably provided in a tube whose both ends are covered and which defines the inside of the tube into two chambers, wherein the tube has a resin-impregnated fiber material on the inner layer side. It consists of two wound layers formed by winding and thermosetting the fiber material with different winding angles on the inner layer side and the outer layer side, and the inner layer side has a larger winding angle, and the outer layer side has a larger winding angle. A cylinder device characterized in that the winding angle of the fiber material is reduced.