JPS5825934A - Manufacture of shock absorber - Google Patents

Abstract

PURPOSE:To manufacture a durable shock absorber which is simple in construction and excellent in absorbing shock by such an arrangement wherein urethane elastomer is caused to foam in a molding frame and after it is foamed and set, the molding frame is disassembled. CONSTITUTION:A molding frame 1 is provided so that its one side is opened and brought to directly contact with the side of a pier G. Urethane elastomer is caused to foam within this molding frame 1. Upon completion of foaming, as the molding frame 1 is disassembled, a fender which is strongly adhered to the pier G by the adhesive power of urethane elastomer itself is formed. By this manner, a shock absorber which is simple in construction and excellent in durability and shock absorption can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a book relating to a method for manufacturing a shock absorber that absorbs the impact of ships docking and other heavy objects.

Conventional shock absorbers have generally been formed from molded bodies of elastic materials, but they have the following drawbacks.

<B> Since impact energy is absorbed through bending deformation of the rubber elastic material, deformations such as compression, shearing, and elastic buckling occur! Proceed in 6 parts.

During this time, it was impossible to equalize the internal stress, so the life of the absorber was short.

As shown in Figure 6, a shock absorber made of elastic material deforms geometrically (a') by applying a force in the direction of the arrow to the hollow cylinder (,) to absorb the amount of displacement. It is.

Therefore, as the cross-sectional shape changes, the characteristics during compression change.

(No.): The shock absorber made of P-mu elastic body is
As shown in the figure, the bearing pressure strength changes depending on the compression ratio.

Therefore, as the amount of deformation increases, the impact energy exceeds the surface pressure strength of the ship before it reaches zero, resulting in deformation of the outer plate of the ship.

(g) When deformed, the area in contact with a heavy object such as a ship, that is, the pressure-receiving area changes, but in the case of a thumb elastic body, the spring constant changes as the pressure-receiving area changes.

Kushisam molded products are manufactured by applying a putty-like semi-fluid over and over again.

Therefore, it is not possible to manufacture a composite structure in which other materials, such as reinforcing materials, are embedded, and it is impossible to expect a function beyond that of the shim elastic body alone.

g) Since a vulcanization process is required to form the shim, it can only be produced in a factory, and there are certain limits to the size of the product.

Therefore, it is necessary to connect the individual products with a connecting material such as Zelto, and the problem of corrosion of the connecting material is unavoidable.

The present invention has been made to improve the above points, and an object of the present invention is to provide a method for manufacturing a shock absorber having a simple structure and excellent durability and shock absorption efficiency.

Next, an example will be described.

The shock absorber of the present invention is made of urethane elastomer with excellent elasticity, self-adhesiveness, and corrosion resistance! Use.

<A> A composition that forms a urethane elastomer.

This urethane elastomer contains ■polyhydric alcohol, ■polyisocyanate, ■urethanization catalyst, ■chain extender, 0
(1) Polyhydric alcohol formed from a composition consisting of a foaming agent and (1) a foam stabilizer. The functional number of the polyhydric alcohol is preferably 15 to &5.

If it is less than 25, the compression set will be large and it will be unsuitable as a fender material.

&5 or more, the elastomer becomes extremely hard and the risk of p-rupture due to vibration compression increases.

The number average molecular weight of polyhydric alcohol is The range of 4500 to 6.500 is preferable.

If it is less than 4.500, the vibration energy absorption characteristics will be low.

This is thought to be because the density of chemical crosslinking points increases and the behavior approaches that of a perfectly elastic body.

If it is more than 6,500, the elastic properties deteriorate and severe deformation tends to occur, and in particular, the compression set becomes large, so it is not suitable.

Examples of the polyhydric alcohol used in the present invention include low molecular weight polyhydric alcohols such as glycerin and trimethylolzotetrapane, low molecular weight active hydrogen compounds such as ethylene cyanocarbonate, ethylene monoxide, zotetrapyrene oxide, etc. A so-called polyether polyol or the like obtained by addition polymerization of an oxyalkylene compound can be used. Similarly, polyester 4-liol, hydrococonium-terminated chain polybutadiene, etc. can also be used.

■ Polyisocyanate Polyisocyanate is usually urethane elastomer.
You can use what is used for.

For example, 4*4'-diphenylmethane diisocyanate, naphthylene diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, etc. can be mentioned, and mixtures of two or more of these can also be used.

Moreover, the polyisocyanate can also be used as a precursor kneaded in advance with the polyhydric alcohol. In any case, the amount of polyisocyanate used is stoichiometrically equal to or ±10% of the active hydrogen-containing component (polyhydric alcohol, chain extender, etc.) to be reacted with the incyanate residue.
It is possible to vary it within a range of about 100%.

■Urethanization catalyst The urethanization catalyst used is those used in normal urethanization reactions, that is, tertiary amino compounds, organometallic compounds, etc., such as triethylenediamine, diazabicyclodecene, N-methylmorpho, etc. Lin, N, N-
1/f/l/Zl The amount of catalyst used, which may include nolamine, tin octylate, diptyltin laurate, etc., can vary within a wide range depending on the desired reaction rate, but the amount to foam the urethane elastomer, Atmospheric conditions (
It is necessary to adjust the amount used appropriately depending on the temperature, temperature, etc.), and it is easy to select this.

(2) Chain extender This reacts with isocyanate to form a hard segment mainly composed of hydrogen bonds through urethane bonds or urea bonds, and controls the elastic properties.

The blending amount of the chain lengthening agent is α2
”'mol/gr -L OX 10-'mol/g
A range of r is preferred.

If it is lower than this, the chain lengthening effect will be insufficient and the strength will be extremely low, impractical.

If it is higher than this, the strength will increase, but the elastomer will be extremely hard)
As a result, compression set and repeated compression fatigue properties deteriorate.

As chain extenders, substantially difunctional compounds with relatively low molecular weights, such as diols and diamines, are used, such as ethylene glycol, polypylene glycol, f.
'H/e diol, butanediol, methylene bis-
(0-dichloroaniline), hydroquinone, and diethylquinone ether in hydrochloride.

(2) Blowing agent Low foaming elastomer of the present invention Generally, water or a fluorinated hydrocarbon can be used as a blowing agent.

The amount of blowing agent required to produce an elastomer having a bulk density of 0.3 to 0.9 f/-, which is the object of the present invention, will be readily determined by a person of ordinary skill in the art.

<Exposure> Properties of urethane elastomer The urethane elastomer used in the present invention has the following properties.

■ Bulk density A material having a bulk density of 0.3 to 0.9 f/cd is used.

If it is smaller than this, the load supporting capacity will be extremely low.

If it is larger than that, it will be more susceptible to volume change due to slight compression.

For the purposes of the present invention, a range of 0.4 to 0.8 f/- is particularly preferred.

■ Spring constant The spring constant per unit area has a value of approximately 1 ky/a, particularly preferably 3 ky/a to 10 ky/a.
Being in the range of j is Ij! ! Values in this range can be obtained by appropriately selecting the composition and bulk density of the urethane elastomer at a thickness of 5 to 100 degrees, which is commonly used as a fender layer.

h) Formation of fender material The case of forming a shock absorber, such as a fender material, using the above-mentioned urethane elastomer will be explained. (Fig. 7) A formwork (1) is provided with the negative side in contact with the quay (b), and the urethane elastomer is foamed within this formwork (1).

When the formwork is dismantled after foaming is completed, a fender material is formed that is firmly adhered to the shore 11 (G) due to the adhesive force of the urethane elastomer itself.

This fender is an elastic material with many closed cells inside.
It has the following effects.

Function of fender ■ Absorption of displacement The fender is pressurized and deforms at 9 o'clock when the ship comes berthing, but this displacement is absorbed by the deformation of the large number of closed cells inside the line of displacement.

Since it is absorbed by the deformation of the bubble group, the compression characteristics do not change even if the amount of displacement increases or decreases.

This point is fundamentally different from conventional fenders, which have a geometric shape that is easy to deform, and as a result, the compression properties change as the shape changes. It is.

■ Spring constant Since the fender of the present invention is an elastic body with a large number of closed cells inside, it absorbs deformation inside the elastic body as shown in the above, and as a result, the range (g) in which the spring constant does not change. exists.

When this is shown in (B) of FIG. 1, the difference from the shape of the spring constant g (A) of the conventional ZAM elastic body is clear.

■ Pressure receiving area and spring constant Even if the area where the ship pressurizes the fender changes, the spring constant does not change.

This is shown in FIG. 2, and the difference between the state of the fender of the present invention (CB) and the state (4) of the conventional fender made of 25 elastic bodies is clear.

■ Non-uniform deformation stress Because the urethane elastomer is foamed within the formwork, the density in the center of the fender is low after it has been constructed, and the density in the periphery is increased as foam growth is suppressed.

As a result, the deformation stress at the center is small and the deformation stress at the periphery is large.

Therefore, while having sufficient deflection as a whole, the third
As shown in the figure, it can be seen that the corners have a large resistance to deformation and have internal resistance that is extremely effective as a shock absorber.

■ Durability A high density around the edges means that the surface is dense.

Therefore, since there is no moisture intrusion, there is no deterioration due to freezing or thawing, and it is not affected by ozone or sunlight, making it especially suitable for use in the ocean where weather conditions are harsh.

■ Creation of composite structure In the above example, we considered the case where only the two stomas were foamed in the formwork, but reinforcing material (2) such as wire or fibers was placed in the frame (1) in advance. It is also possible to allow foaming after that. (Figure 4) This is because the original form of urethane elastomer is liquid, and when producing something with the same hardness as rubber, the viscosity is about 1.
This is possible because the hardness is approximately 000 to 1500 centipoise (when the hardness is 85°).

Since the reinforcing material can bear the tensile force when the fender is pressurized and deformed (Fig. 5), it is possible to reduce the overall cross section, and it is possible to manufacture a companion with excellent durability.

On the other hand, conventional fenders made of rubber elastic bodies are manufactured by stacking m of putty-like semi-fluid materials, as described above, making it extremely difficult to create a composite structure.

As shown in Figure 6, points where stress is concentrated (8)
In many cases, the structure could not be reinforced and was cut and destroyed.

The present invention is a shock absorber manufactured by foaming urethane elastomer as described above.

Therefore, the following effects can be expected.

(A) Even if the amount of displacement increases or decreases, the compression characteristics do not change and the energy of the heavy object can be absorbed in the same state.

G〉　The spring constant does not change even if the deformation progresses.

Therefore, even in a state where a volume change is forced, the energy absorption amount and bearing pressure strength do not change.

Even if the pressure-receiving area changes, the spring constant does not change, so even if the contact area changes with the size of the ship, the effect on the ship's side plate remains the same (by the way, the ship's side plate is small even if the ship is large) Even if it is designed to be about 20t/-).

Ω Density is small in the center and large in the periphery.

Therefore, it is flexible and each corner can resist deformation.

It also has excellent durability because the surrounding area and surface are protected.

(g) Since the material of urethane elastomer is in a liquid state, it is possible to easily create composite structures by combining it with other materials, such as reinforcing steel; can be made to resist external forces.

(g) Unlike rubber elastic materials, it does not require vulcanization and can be foamed and molded anywhere by transporting just the undiluted solution, making it easy to construct on-site. Also, rubber materials are used because they are not subject to shape or size restrictions. There is no need to take the trouble of connecting small cross-section members with gels or the like as in the case of the conventional method, and problems such as corrosion of the connecting members do not occur.

[Brief explanation of drawings]

Figure 1: A diagram showing the relationship between compression ratio and bearing pressure strength. Figure 2: A diagram showing the relationship between pressure-receiving area and spring constant! Figure g3: An explanatory diagram of the shape of the material. Figure 4: An explanatory diagram of the method of forming nine fenders by arranging reinforcing materials. Figure 5: An explanatory diagram of the deformed state of the embodiment shown in Figure 4. Figure 6. An explanatory diagram of the deformed state of the fender Figure 7: An explanatory diagram of the method of forming the fender 1: Frame, 2: Reinforcing material

Claims (1)

[Claims] Inside the formwork, Foam urethane elastomer, This is done by dismantling the formwork after foaming. Manufacturing method of shock absorber