JPS63293396A - Pulsation preventive device for fluid - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a device for preventing pulsation that occurs when fluid (particularly liquid fluid) is pumped from a pumping section to a destination via piping, etc. The present invention relates to a fluid pulsation prevention device for preventing fluid pulsation that occurs when fluid is pumped by a pump that tends to cause pulsation, such as a pump, plunger pump, or gear pump.

(Background of the Invention) Diaphragm pumps are generally used to pump liquids or gases such as solvents, paints, and photosensitive coating liquids to other devices or equipment through piping such as vibrators.

Pressure pumps that prevent pulsation, such as plunger pumps and gear pumps, are often used.

However, when the fluid pulsates rapidly during pressure feeding, the transportation and supply of the fluid becomes intermittent, making it difficult to transport and supply the fluid quantitatively.Moreover, the pressure fluctuations caused by the pulsation cause an overload on the pressure pump. , which may cause the pressure pump to malfunction.

Furthermore, when the photosensitive coating liquid is pumped to a coating device and applied, if there is pulsation of the photosensitive coating liquid during pumping, it will not be possible to obtain a uniformly coated product, and therefore the purpose of the photosensitive material will not be achieved. I can't. Furthermore, during the painting process using paint or the like, the paint or the like is discharged unevenly or intermittently, making it extremely difficult to apply the paint uniformly.

Therefore, when such a pressure pump pumps liquid through piping or other piping, it is necessary to reduce the pulsation of the liquid as much as possible. (Prior art) Conventionally, as a method of preventing or reducing the above-mentioned pulsation that occurs during the pumping of liquid, a sealed hollow chamber is connected to a part of the route pipe from the pumping section of the pump or the like to the destination section. The pulsations that occur during pumping and pumping are absorbed by the compression and expansion of the air within the hollow chamber. This hollow chamber is in a sealed state except that the inside thereof is in communication with the route pipe, and the air pressure inside the chamber is in a state equal to atmospheric pressure before the liquid is pumped. Since the liquid is forced into the hollow chamber during pressure feeding, the air pressure within the hollow chamber rises to above atmospheric pressure.

Also, JP-A-56-180497, JP-A-58-21
There were inventions and ideas disclosed in Japanese Patent No. 7890 and Japanese Utility Model Application Publication No. 59-73692.

(Problems to be Solved by the Invention) However, various deficiencies have been recognized in these conventional pulsation prevention methods.

In the method of communicating the sealed hollow chambers, the degree of pulsation of the liquid that occurs during pumping depends on, for example, the type of pump and the pumping pressure.

It varies significantly depending on conditions such as the amount of pumping, the flow characteristics of the liquid to be pumped, and the material and inner diameter of the route pipe.

On the other hand, the size of the hollow chamber for preventing pulsation of the liquid communicated with the path pipe needs to be determined depending on the degree of pulsation of the fluid, and the larger the pulsation, the larger the internal volume of the chamber. be. Therefore, the size of the hollow chamber is currently designed based on the above-mentioned conditions, and chambers with various internal volumes are required, which requires a large amount of manufacturing cost and labor.

In addition, in the process of pumping expensive liquids such as photosensitive coating liquids or liquids that change over time using the above method, if the pulsation is large, it is necessary to use a hollow chamber with a large internal volume to prevent the pulsation. , a large amount of liquid flows into the chamber during pumping. A large amount of liquid that has flowed into the chamber after the end of the pumping has to be discarded, resulting in a loss, which is economically disadvantageous.

As a method for improving such various defects, Japanese Patent Application Laid-Open No. 160497/1983 discloses that the air pressure inside the hollow chamber is increased above atmospheric pressure in advance, and then the liquid is pumped. .

However, even in this method, when the dissolved gas (for example, dissolved air) in the liquid is removed in advance (called deaeration treatment) and the liquid is fed under pressure, the deaeration process may occur if the liquid is fed under pressure for a long time in the hollow chamber. The liquid that was
Since it absorbs air, it not only reduces the effectiveness of the degassing process but also has the drawback of increasing the amount of liquid flowing into the hollow chamber.

Furthermore, the pulsation prevention method using the hollow chamber has the disadvantage that it requires a great deal of effort and time for cleaning when changing the liquid to be pumped to another liquid.

As an alternative to the pulsation prevention method using the hollow chamber which has the above-mentioned drawbacks, Japanese Patent Application Laid-Open No. 58-217890 and Japanese Utility Model Application No. 59-73892 disclose a pulsation prevention method using an elastic tube that can be expanded and contracted in the radial direction. Disclosed.

However, in these pulsation prevention methods using elastic tubes, when an organic solvent, a photosensitive coating liquid using an organic solvent as a solvent, or an aqueous photosensitive coating liquid containing an organic solvent is used, the elastic tube is It has the disadvantage that it swells or dissolves in organic solvents, loses its properties, and sometimes fails to provide an anti-pulsation effect.

Therefore, the emergence of an elastic tube that can withstand organic solvents has been strongly desired, but at present there is no inexpensive elastic tube that can withstand all types of organic solvents when used to prevent pulsation. Although there are elastic tubes made of materials that can withstand this, they are extremely expensive and economically disadvantageous.

An object of the present invention is to provide a fluid pulsation prevention device that solves the problems of the prior art described above.

(Means for Solving the Problems) According to the present invention, there is provided a flexible tube or a hollow substantially spheroid, and a cross-sectional area of the hollow portion of the tube or substantially spheroid is smaller than its maximum cross-sectional area. The fluid comprises a member acting as an elastic body that elastically restricts the cross-sectional area of the fluid, and the member acting as the elastic body has an elastic force having a gradient in the direction of the main axis of the tube or substantially spheroid. The above object is achieved by the anti-pulsation device.

Here, the main axis direction of a flexible tube or hollow substantially rotating body refers to its long sleeve direction, and generally is often the axis direction connecting the entrance and exit.

(In the case of a pipe, the inlet/outlet is perpendicular to the main axis of the pipe,
Alternatively, it can also be opened on the side. ) (Preferred Embodiment) The flexible tube or hollow substantially spheroid in the pulsation prevention device of the present invention may be one whose cross-sectional area changes without changing at least the circumferential length of the cross-section. , the shape partitioned by the inner wall of the chain tube when the internal volume of the chain tube is maximized is not particularly limited, but 9 cylindrical shape, elliptical cylindrical shape 1
Preferably, the shape is spherical, polygonal columnar, or a combination thereof.

The cross section of the shape partitioned by the inner wall of the chain tube when the inner volume of the flexible tube is at its maximum is not particularly limited, but it is preferably 2 circles, an ellipse, or a polygon.

The inner diameter or outer diameter of the central hole of the flexible tube or hollow substantially spheroidal body is not limited, and may be the same diameter, larger diameter, or smaller diameter than the route pipe.

The diameter of the center hole in the portion where the flexible tube or the hollow substantially spheroidal body connects with the route tube is not particularly limited, and may be the same diameter as the route tube or may be smaller. A hole like this is inserted into a flexible tube or a hollow approximately spheroid.
One may be provided to serve as a fluid exit, or two or more may be provided to separate fluid exits.

The cross-sectional area of the central hole of the flexible tube or hollow substantially spheroid is restricted to a constant cross-sectional area less than the maximum cross-sectional area by a member that directly acts as an elastic body. The present invention is not limited to this, and the cross-sectional area may be elastically limited to a constant cross-sectional area that is less than the maximum cross-sectional area indirectly via a rigid body.

The members acting as elastic bodies in the pulsation prevention device of the present invention include springs such as coil springs, spiral springs, leaf springs, and bamboo shoot springs, as well as known elastic bodies such as natural rubber, various synthetic rubbers, and synthetic resins. It also includes those in which fluids such as gases and liquids are surrounded by flexible or stretchable membranes or containers, or those in which the shape is restricted, and those in which rigid bodies are combined with these.

The member acting as an elastic body having an elastic force having a gradient in the longitudinal direction of the tube or substantially spheroid can be obtained by changing the shape, structure, or combination of the members acting as the elastic body as described above. .

The flexible tube or hollow substantially spheroid (hereinafter referred to as flexible tube, etc.) used in the fluid pulsation prevention device of the present invention basically has its circumferential direction, length direction, etc. An elastic material that does not stretch or contract but is only flexible in the radial direction can be used.

When using organic solvents, photosensitive coating liquids using organic solvents, and photosensitive coating liquids containing solvents, there are problems with the chemical resistance of elastic tubes, or the economic efficiency of using expensive elastic tubes. There are no problems.1 For example, polyethylene, polyethylene hexafluoride, and other relatively inexpensive materials such as Teflon, which are stable against most organic solvents, can be used.
It can be used to mold tubes with any flexibility.

Although it depends on the wall thickness of a hose made of polyethylene hexafluoride, its expansion and contraction is extremely small compared to a single elastic tube, so it has the ability to absorb pulsations through expansion and contraction in the circumferential direction and length direction, as described above. is extremely low.

However, the mechanism that originally prevents pulsation using elastic tubes, etc.
This can be thought of as a periodic change in the volume of the elastic tube because it absorbs changes in the discharge amount that occur periodically in pressure pumps, etc. by increasing and decreasing the internal volume using the elastic tube's expansion and contraction (particularly in the circumferential direction). .

Therefore, when a pressure pump or the like is used to pump liquid, the pulsation prevention means may be any means that uses a function that changes the volume according to the pressure of the liquid even when using a hose, etc., and there is no need to use an elastic tube. There is no need to use expansion and contraction like this.

One example of such means is to use a member that acts as an elastic body having an elastic force that has a gradient in the direction of the main axis of the tube, etc. by changing the radial cross-sectional area of a flexible tube such as a circular or nearly circular hose. By reducing the maximum cross-sectional area in advance and elastically restricting the shape to an ellipse or close to an ellipse,
When the magnitude of the pressure absorbs pulsations over a wide range and the cross-sectional area increases, the cross-sectional shape in the radial direction becomes a circle or a shape close to a circle, and a method of repeating this is considered.

By utilizing such changes, it is possible to increase or decrease the volume without changing the length and circumference of the hose, etc., and it is possible to provide a function to prevent pulsation over a wide range of pressure.

According to the principle of the pulsation prevention means of the present invention, the hose or the like used to increase or decrease the volume may have flexibility in at least one cross section, and is limited to the shape described above. It's not a thing.

In addition, in order to increase the pressure resistance of flexible pipes, reduce costs, or make them elastic so that they can follow the frequency of pulsation, only the parts that come into contact with organic solvents are made with chemical resistance. A certain material (e.g. 0.5~2.5tu
Needless to say, composite hoses made of polyethylene hexafluoride (hexafluorinated polyethylene, etc.) with a wall thickness of 1.5 mm and whose outside is molded with rubber or the like are also included in these flexible tubes. Furthermore, flexible tubes and the like also include tubes made of a stretchable material such as rubber, which are regulated by non-stretchable threads, wires, etc. so that the material does not expand or contract.

(Example) Next, the pulsation prevention device of the present invention will be specifically described. An example of this is a pulsation prevention device that repeats an elliptical or nearly circular shape by elastically regulating the radial cross section of a flexible tube such as a hose with an elastic body,
Figures 1-a, 1-b, and 1-c show cross sections of a pair of elastic bodies 1 and 1' constituting the tube whose thickness is gradually changed in the longitudinal direction and tapered. However, the present invention is not limited to this shape.

The radial cross-sectional area of the flexible tube 3, such as a hose, is reduced from its maximum area in advance, and after absorbing the pulsations of the liquid by increasing the cross-sectional area, the cross-sectional area is reduced again to the original cross-sectional area. Therefore, as shown in FIG. 1-a, an elastic body 1. such as a leaf spring is an example of a member that acts as an elastic body.
1' is fixed with spacers 2, 2', bolts 5.5' and nuts 6.6', and then a flexible tube 3 is inserted between the elastic bodies 1, 1' as shown in Fig. 1-b. will be established.

Liquids 4 and 4' pumped by a pressure pump that generates pulsation, such as a diaphragm pump, plunger pump, or gear pump, are pumped through a flexible tube 3; After that, when back pressure is applied by a valve or the like (not shown), the pressure increase due to the pulsation of the liquids 4, 4' causes the volume of the flexible tube 3 to increase as shown in Figure 1-c. absorbed by.

The flexible tube 3, which has increased in volume by absorbing the pressure increase due to pulsation, is then subjected to a force by the instantaneous elastic bodies 1 and 1' to reduce its volume, as shown in Figure 1-b. Return to the state before the increase in volume.

By elastically regulating the flexible tube 3 by a pair of tapered elastic bodies 1 and 1', the magnitude of the pressure generated by the pressure pump can be varied over a wide range. Pulsation can be prevented.

Furthermore, even if the thickness of the elastic bodies 1 and 1' shown in the figure is uniform, by changing the height of the spacers 2 and 2' in the longitudinal direction of the flexible tube 3, the thickness of the elastic bodies 1 and 1' can be changed. 1′
If they are made non-parallel, it is possible to create a member that acts as an elastic body with continuous elastic force.

1-d is a side view of another embodiment of the pulsation prevention device of the present invention.
In the figure, a sectional view taken along the line I--I of FIG. 1-d is shown in FIG. 1-e. The rigid bodies d2 and d2' are joined to the rigid body d1' so that they do not easily separate.

It is not joined to the rigid body d1. Spring d5 and d5'
are opposed to each other with a flexible tube d3 in between. Other springs d6. Similarly, d7 and d8 are opposed to springs d6', d7' and d8' (not shown).

The flexible tube d3 through which the liquid fluid e1 flows is a rigid body d.
They are regulated directly and indirectly by i, di', d2 and d2', and springs d5 to d8. If pulsation occurs,
The cross-sectional area of the flexible tube d3 increases and decreases to absorb pressure changes due to pulsation. At this time, since the density of springs is greater on the left side of Figure 1-d than on the right side, the flexible tube d3 is regulated by an elastic force that has a gradient from the left side to the right side of Figure 1-d. The magnitude of the pressure can effectively control pulsations over a wide range.

Although the rigid bodies d2 and d2' are plate-shaped, they may be formed into one or more columnar shapes or may be divided.

Further, the elastic forces of the springs d5 and d5' may be changed, or the heights of the spacers d2 and 62' may be changed.

As explained above, the fluid pulsation prevention device of the present invention has the following features:
The increase in fluid pressure due to pulsation that occurs when fluid is pumped is absorbed by the increase in volume of the flexible tube in at least one cross section, so the factors that affect the pulsation prevention effect include: 1. There are various factors such as the shape, structure, or material of the member that acts as an elastic body, the type of pressure pump, the amount of pressure pumped, etc.

These are appropriately selected depending on the flow characteristics of the fluid used, the material of the path tube, its shape, and the target pulsation.

For example, when the elastic force of a member that acts as an elastic body is large, and when the pressure applied to the fluid flowing through the flexible pipe, etc. in at least one cross section is low, the volume of the flexible pipe, etc. Since the increase is extremely small, the anti-pulsation effect is small, and on the other hand, when the pressure is too high, the anti-pulsation effect is also reduced. Furthermore, if the elastic force of the member acting as an elastic body is small, the pulsation prevention effect will be small even when the pressure applied to the fluid flowing through the flexible pipe or the like is high.

In other words, the shape of the member that acts as a 9 elastic body.

This means that once the structure or material is determined, there is a pressure that effectively prevents pulsation.

Even if a combination of a rigid body and a coil spring or the like that contributes to elasticity is used as a member that acts as an elastic body, it is possible to increase or decrease the volume of the flexible pipe, etc., so pulsation can be effectively prevented in this case as well. There is pressure.

Originally, the member that acts as an elastic body should be appropriately selected to be effective over the entire pressure range of the pulsation that occurs, but the pressure range of this pulsation is the range of the elastic force of the member that acts as an elastic body. In some cases, it may not be possible to effectively prevent pulsation by exceeding this value.

A member that acts as an elastic body provided in a flexible pipe or the like is required because if its shape, structure, or material is selected appropriately, pulsation can be effectively prevented within the corresponding elastic stress range. to cover the entire pulsating pressure range.

Pulsation can be effectively prevented by a member acting as an elastic body with an expanded elastic force range. As an example of this, a flexible tube as described above is elastically restricted by a pair of plate-like elastic bodies by tapering the cross section of the tube in the longitudinal direction (Fig. 2-b). ), or by a plate-like elastic body with a slope or taper (Fig. 2-a).

Figure 2-a is a plan view showing an embodiment of the present invention,
Figure 2-b is a diagram showing an example of the cross section taken along the line ■-■ in Figure 2-a, and Figure 2-C is a diagram showing another example of the cross-section taken along the line ■-■ in Figure 2-a. Note that these figures show the state when the fluid pressure is not applied to the flexible tube 23.

The flexible tube 23 is elastically regulated by the plate-like elastic bodies 21 and 21' at the height of the spacers 22 and 22'. Spacer 2 between plate-like elastic bodies 21 and 21'
2 and 22' are located, and these are screws 25a and 25b.
etc. and nuts 26a, 26b, etc.

In Fig. 2-b, a temporary elastic body of uniform thickness is placed at the height of the tapered spacers 22 and 22' whose height gradually changes in the longitudinal direction of the flexible tube 23. 2
1 and 21', the flexible tube 23 is elastically restricted.

In Figures 'lc', a flexible tube 23 is elastically restrained by tapered plate-like elastic bodies 21 and 21'.

In FIG. 2-a, either the plate-like elastic body 21 or 21' may be sloped or tapered.

Furthermore, the cross section of the flexible tube in the direction perpendicular to the direction of fluid flow may be tapered and elastically restricted, or the cross section may be formed with a sloped or tapered elastic plate. It may be regulated.

FIG. 2-d also shows the flexible tube 2 shown in FIG. 2-a.
A hollow substantially spheroid 23d having flexibility instead of 3
A plan view of another embodiment of the pulsation prevention device using the pulsation prevention device is shown. In Figure 2-e.

A sectional view taken along the line IV-IV when the pulsation prevention device shown in FIG. 2-d absorbs pulsation is shown. Figures 2-f and 2-g show the state when the substantially spheroidal body 23d is restrained by the plate-like elastic bodies 21d and 21d', and when the substantially spheroidal body 23d absorbs pulsation, respectively. 2
FIG.

The flexible hollow substantially spheroidal body 23d is elastically restrained by the plate-like elastic bodies 21d and 21d' so that its cross section becomes approximately elliptical (Fig. 2-f), but when pulsation occurs, Its cross section is almost circular and absorbs pulsating pressure (Figure 2-g). At this time, as shown in FIG. 2-e, the distance between the plate-shaped elastic bodies 21d and 21d' changes in the direction of the principal axis of the substantially spheroidal body 23d.

Note that the plate-like elastic bodies 21d and 21d' are spacers 22d.
and 22d' with screws 25d, 25d', etc. and nuts 26d, 26d', etc. 4e indicates a fluid.

Figure 3 shows the flow of the experimental equipment used to confirm the above effects. In Figure 1, A is a liquid stock tank, B is a liquid stock tank,
C is a pressure pump, D is a pressure gauge, E is 1-a, 1-
b, the flexible tube 31 shown in Figure 1-a, the elastic bodies 1, 1', and other members (including those not shown)
F is a valve for applying back pressure to the flexible tube 3 in the pulsation prevention device E, and G is a flow meter for measuring pulsation.

Liquid B is sucked from liquid stock tank A by pressure pump C and supplied to pulsation prevention device E. A valve F for pressurizing the liquid in the flexible tube 3 of the pulsation prevention device E is installed after the pulsation prevention device E, and this valve F is adjusted 21 and measured by a pressure gauge. Set pressure. A gauge G is attached to measure the pulsation of the liquid that has passed through the valve F, and the liquid is returned to the liquid stock tank A.

This is an attempt to evaluate the pulsation prevention ability of the present invention.

Examples of the present invention will be described below using more specific experimental examples, but these experimental examples do not limit the scope of the present invention in any way.

(Experimental Example) Experimental Example 1 Using the experimental apparatus shown in FIG. 3, the pulsation of a photosensitive coating liquid having the composition and physical properties shown in Table 1 was measured.

1. Pulsation prevention device ■ Mouth ■ Flexible tube a, inner diameter 35 mm b, length 700 C1 shape composite hose Inner hexafluoride polyethylene wall thickness 0, 3
mrm Outside EPT rubber (rubber hardness 70) Wall thickness 4 mm ■Elastic body a, material PVC board (transparent) b,
Size 600mm (L) X 350au+
+(W) X 2nm(t)C, spacer interval ('
J length 300m + sd, spacer height (h) 10mm and 30mm at both ends respectively 2. Pressure pump ■Form: Non-pulsating type (2 units) Plunger pump ■Motor rotation speed Max. 1.42 Or, p, m ■Discharge rate Max. 4. 3β/min (blank below) Table 1 Photosensitive coating liquid
As shown in Figure b, the pulsation prevention device was installed and incorporated into the experimental apparatus shown in Figure 3, and the pressure applied to the photosensitive coating liquid passing through the flexible tube was varied by valve F, and the pulsation at that time was controlled. The results measured with flowmeter G are shown in Figure 4.

"Pulsation rate" is defined as a term expressing the degree of pulsation as follows. In a pressure pump, the ratio of the average discharge of 4 m (Q) when the motor is set to a certain rotation speed and the fluctuating discharge (ΔQ) at that discharge amount expressed as a percentage is expressed as a linear equation.

curvature Comparative experiment example 1 Only the elastic spacer in Experimental Example 1.

10mm (elastic body condition I) and 30mm (elastic body condition ■)
A straight spacer was used, and the pulsation was measured under the same conditions as in Experimental Example 1. The results are shown in Figure 5.

Experimental Example 2 The elastic body of the pulsation prevention device in Experimental Example 1 was constructed as shown in Fig. 2-c and under the following conditions.

Pulsation was otherwise measured under the same conditions as in Experimental Example 1. The results are shown in Figure 6.

Elastic body condition a, material PVC board (transparent) b, size 600mm (L) x 350Il1m (W) x (
bnm ~3a+m(t))C, spacer spacing (1) 300 m+s d, spacer height (h) 20 m+s Comparative Experimental Example 2 Only the thickness of the elastic body of the pulsation prevention device in Experimental Example 2,
1 mm (elastic body condition I') and 3 mm (elastic body condition ■'
), and the pulsation was determined under the same conditions as in Experimental Example 2, except that two pulsation prevention devices were used. The results are shown in FIG.

According to the results of Experimental Example 1 and Comparative Experimental Example 1.

The pulsation rate of the pulsation prevention device (Experimental Example 1) in which the elastic body is plate-shaped and the interval between the plates is tapered in the length direction of the flexible tube is as follows: The pressure applied to the photosensitive coating liquid is 0.3 [ kg/c
d gauge pressure] to 2.5 [kg/cJ gauge pressure], it is within the range of about 0.7% to 0.9%.

On the other hand, in the pulsation prevention device of Comparative Experimental Example 1, the pulsation rate fluctuates more depending on the applied pressure than in Experimental Example 1, and the pulsation rate is wider.

Furthermore, according to the results of Experimental Example 2 and Comparative Experimental Example 2, even if the pressure applied to the photosensitive coating liquid in Experimental Example 2 changes in the same manner as above, the pulsation rate is within the range of approximately 0.5% to 0.7%. There is, but
Compared to Experimental Example 2, the pulsation rate in Comparative Experimental Example 2 has a larger variation with respect to pressure.

Therefore, a pulsation prevention device in which the elastic body is made into a plate shape and the interval between the plates is tapered, or the thickness of the plate-shaped elastic body is continuously changed, is extremely remarkable in terms of the stability of the pulsation rate with respect to pressure. It can be seen that this has a great effect.

In the experimental examples and comparative experimental examples, a polyvinyl chloride board is used as the elastic body, but if other elastic bodies or flexible pipes are used, it is expected that the binding will be different, and the optimal It is thought that conditions also exist.

As described above, the fluid pulsation prevention device according to the present invention has the following features:
Despite its simple configuration, it is possible to keep pulsation low over a wide range of pressures applied to the pressure pump, from low to high.

Therefore, in addition to being able to transport and supply fluid quantitatively, when applying a photosensitive coating liquid that uses or contains an organic solvent with a coating device, it is possible to obtain a uniform photosensitive film even if the pressure applied to the pressure pump is applied over a wide range. Not only can this be done, but when applying an organic solvent-based paint, it is possible to achieve a uniformly coated surface.

Furthermore, the structure is not only simpler than when using a hollow chamber.

It is extremely economical in terms of cost, labor, fluid loss, and cleanability, and it is also extremely economical in terms of manufacturing cost and versatility for the fluids used compared to elastic tubes that can be expanded and contracted in two circumferential directions. be.

[Brief explanation of the drawing]

FIG. 1-a is a sectional view of a member that acts as an elastic body in the pulsation prevention device according to the present invention. FIG. 1-b is a cross-sectional view when the pore of the flexible tube of the pulsation prevention device according to the present invention is restricted to a cross-sectional area less than the maximum cross-sectional area. FIG. 1-c is a sectional view when the flexible tube of the pulsation prevention device according to the present invention absorbs pulsation. 1-d is a side view showing another embodiment of the fluid pulsation prevention device according to the present invention. Figure 1-e is a sectional view taken along line I-1 in Figure 1-d. Figure 52-a is a f-side view showing an embodiment of the pulsation prevention device of the present invention. FIG. 2-b is a diagram showing an example of a cross section taken along line nm in FIG. 2-a. FIG. 2-c is a diagram showing another example of the cross section taken along the line ■-■ in FIG. 2-a. FIG. 2-d is a plan view showing another embodiment of the pulsation prevention device of the present invention. FIG. 2-e is a sectional view taken along the line IV-IV in FIG. 2-d. 2-f and 2-g are sectional views taken along the line v-V of FIG. 2-d. FIG. 3 is a schematic diagram of an experimental device used to confirm the effect of the pulsation prevention device of the present invention. FIG. 4 is a diagram showing the experimental results of Experimental Example 1. FIG. 5 is a diagram showing the experimental results of Comparative Experiment Example 1. FIG. 6 is a diagram showing the experimental results of Experimental Example 2. FIG. 7 is a diagram showing the experimental results of Comparative Experiment Example 2. 1, 1', 21.21', 21d, 2
1d'...Elastic body 2, 2', d2. d
2', 22. 22', 22d. 22d'...Spacer 3, d3.23. 23d...Flexible tube 4
．． 4'...Liquid 5, 5' 25a, 25b, 25d,
25d' - Bolt 6, 6' 2Ba, 2
Gb, 28d, 26d'-...Natsuto C...
Pressure pump D...Pressure gauge E...Pulsation prevention device F...Valve G...Flow meter Applicant Fuji Photo Film Co., Ltd. Agent Patent attorney Asami Kato (1 other person) Part 1-a Figure 1-1) Figure 1-a Figure 1-d Figure 1-a Figure 2-a ■ Figure 2-b jl! Figure 2-a Figure 2-d Figure 2-e Figure 2-f Figure 2-g Figure 1a M3 figure □ Pressure (kg/crfI gain, pressure) - 1 Pressure (
kg/cm gain pressure] Figure 7

Claims (1)

[Claims] A flexible tube or hollow substantially spheroidal body, and a member that acts as an elastic body that elastically restricts the cross-sectional area of the hollow portion of the tube or substantially spheroidal body to a cross-sectional area less than its maximum cross-sectional area. A fluid pulsation prevention device characterized in that the member acting as the elastic body has an elastic force having a gradient in the direction of the main axis of the tube or substantially spheroid.