JP2004052857A - Uniform load type screw-topped high pressure vessel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a screw-topped high pressure vessel reducing load concentration generated on a screw portion and having a long lifetime. <P>SOLUTION: In the screw-topped high pressure vessel having a vessel 2 and a screw top 3 screwing to an opening of the vessel 2, internal diameters of a female screw 5 are set to be constant and outer diameters of a male screw 6 are formed to be smaller quadratically along the inner direction of the vessel 2 beforehand, so as to quadratically widen a gap between the female screw 5 formed on the opening of the vessel 2 and the male screw 6 formed on the screw top 3 along the inner direction of the vessel 2 so that the male screw 6 engages with the female screw 5. Consequently, the total of a stretch of the female screw 5 and contraction of the male screw 6, which are caused by a predetermined inner pressure P of the vessel 2, is equalized to the gap formed beforehand. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a screw cap type high pressure vessel.
[0002]
[Prior art]
FIG. 6 is a sectional view showing an example of a conventional screw cap type high pressure container.
[0003]
As shown in FIG. 6, the screw-lid high-pressure container 11 has a container 12 and a disk-shaped screw lid 13 that is screwed into an opening of the container 12 by rotating. The screw portion 14 is formed so that the outside of the screw cover 13 and the screw cover 13 face each other and mesh with each other. Although details are shown in FIG. 7, between the container 12 and the screw lid 13 is sealed with a sealing material or the like so that the inside of the screw lid type high pressure container 11 can be maintained at a high internal pressure P.
[0004]
FIG. 7 is a diagram showing, together with the cross section and load distribution of the threaded portion obtained by enlarging the portion B in FIG.
[0005]
As shown in FIG. 7, the screw portion 14 of the screw-lid high-pressure container 11 has a female screw 15 on the container 12 side and a male screw 16 on the screw lid 13 formed by parallel threads over the entire length. When the screw lid type high pressure vessel 11 is closed by screwing the screw lid 13 into the screw hole, the screw 15 and the male screw 16 are meshed with each other over the entire length of the screw portion 14 because they are formed in parallel. The screw cover 13 is provided with a ring seal 7 provided on a portion of the screw cover 13 facing the inner wall of the container 12 so as to maintain the internal pressure P of the screw cover type high-pressure container 11, and a ring seal 7 formed on the screw cover 13. And a seal holding ring 8 supported from the inside. Generally, a high-pressure container is operated in a closed state while repeatedly maintaining an internal pressure at a high pressure and a normal pressure at predetermined intervals.
[0006]
The load distribution shown in FIG. 7 shows the load in the length direction of the screw portion 14 when the internal pressure P is applied inside the container 12 in the screw-lid high-pressure container 11 having the above structure. The load value is measured at an evenly spaced position of the portion 14, and the load value is used as a coefficient with respect to the average load to show the distribution in the length direction of the screw portion 14.
[0007]
As shown in FIG. 7, the load on the screw portion 14 due to the internal pressure P is maximum at the screw thread closest to the inner surface of the screw cap 13, and decreases quadratically as the screw cap 13 approaches the outer surface of the screw cap 13. From this, it can be seen that load concentration occurs on the side of the screw thread closest to the inner surface of the screw lid 13.
[0008]
[Problems to be solved by the invention]
When a high pressure is applied to the inside of the screw-cap high-pressure container 11, in the screw-cap high-pressure container 11 having the above-described structure, a uniform distribution of the internal pressure P is applied to the inner surface of the container, and the inner surface of the screw cap 13 is also uniformly applied. The internal pressure P having a suitable distribution is applied. Since the internal pressure P applied to the inner surface of the screw cap 13 is supported by the screw cap 13 and the container 12, the internal thread 15 of the container 12 and the external thread 16 of the screw cap 13 are engaged with each other over the entire length by a screw portion 14. You will receive that power.
[0009]
If the container 12 and the screw lid 13 do not undergo any elastic deformation and the internal pressure P is supported by the screw portion 14, since the load is received by each screw thread, the load concentration as shown in FIG. Absent. However, in practice, a compression force is generated in the screw cap 13 due to the internal pressure P, and a tensile force is generated in the container 12 at the same time. The maximum load concentration due to the internal pressure P occurs at the innermost end. As shown in the load distribution diagram of FIG. 7, a load concentration of 4.819 times the average load occurs at the innermost end of the screw portion 14. The magnitude and distribution tendency of the load do not improve even if the length of the screw portion 14 is increased. Similarly, a load concentration occurs at the innermost end of the screw portion 14.
[0010]
Because of the above-mentioned load concentrated portion, in the screw cap type high pressure vessel 11, when high pressure is repeatedly applied to the screw cap 13 from the inside, the load concentrated portion of the screw portion 14 is easily broken by metal fatigue, and the screw cap type There is a problem that the life of the high-pressure vessel 11 is shortened. As will be apparent from the graph of FIG. 5 described later, as the load concentration increases, the amplitude of the stress intensity generated by the load increases, and the allowable number of repetitions (life) decreases exponentially. That is, the size of the load concentration greatly affects the life of the screw-lid high-pressure container 11.
[0011]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a screw-lid high-pressure container that reduces the load concentration generated in a screw portion and has a long life.
[0012]
[Means for Solving the Problems]
A screw-lid high-pressure container according to the present invention that solves the above-mentioned problems has a container, a screw lid that is screwed into an opening of the container, and a screw formed in the opening of the container and a female screw that meshes with the female screw. It is characterized in that a gap between the screw cap and the male screw is formed in advance so as to fit in a quadratic function along the inside of the container.
[0013]
The screw-top high-pressure container according to the present invention that solves the above-mentioned problem has a constant inner diameter of the female screw and an outer diameter of the external thread along the inward direction of the container, as a quadratic function. It is characterized by being made smaller in size.
[0014]
The screw lid type high-pressure container according to the present invention that solves the above-mentioned problems has a structure in which a load applied to the male screw and the female screw by a predetermined internal pressure of the container is uniform over the entire length of the mesh between the female screw and the male screw. The gap is set so as to be dispersed in the gap.
[0015]
The screw-type high-pressure container according to the present invention that solves the above-mentioned problems is characterized in that, according to a predetermined internal pressure of the container, the sum of the lengthwise elongation of the female screw and the contraction of the male screw in the longitudinal direction is smaller than that of the female screw. Over the entire length of engagement between the male screw and the male screw, the gap is made equal to the gap formed in advance.
[0016]
A screw-top high-pressure container according to the present invention that solves the above-mentioned problem is characterized in that a quadratic function representing the gap is expressed by the following expression.
δ _L = (σ _N0 / (2 × E _N × L) + σ _B0 / (2 × E _B × L)) × X ²
Here, δ _L is a gap in the length direction of the female screw and the male screw, σ _N0 is an axial tensile stress at the innermost end of the female screw due to the internal pressure of the container, and σ _B0 is a value according to the internal pressure of the container. axial compressive stress at the deepest end of the external thread, X is the distance from the proximal position of the female screw and the male screw, E _N is the Young's modulus of the female screw, E _B is the Young's modulus of the external thread , L are the lengths of the internal and external threads.
In the case the Young's modulus _{E B} of the Young's modulus _{E N} of the internal thread the external thread are equal _{(E N = E B = E} ), the above equation is as follows.
δ _L = (σ _N0 + σ _B0 ) × X ² / (2 × E × L)
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
In order to function as a screw-cap high-pressure vessel, the thread of the vessel and the screw cap need to function as a screw with each other. For this purpose, the minimum pitch and flank angle of the thread (half angle of the thread) are required. They must be identical to each other. Furthermore, in order to reduce the load concentration generated on the screw portion of the container and the screw cap, it is necessary to adopt a screw structure in consideration of the elastic deformation of the container and the screw cover.
[0018]
In order to achieve a structure that satisfies the above requirements, in the present invention, by using a male screw and a female screw having the same thread pitch and flank angle, without impairing the function as a screw, furthermore, a male screw and a female screw By making the gap between the threads of the thread according to the elastic deformation of the container and the screw lid, the load can be evenly distributed in the length direction of the screw part without concentrating the load on some threads. And
[0019]
Specifically, in consideration of the stress of the external thread and the internal thread due to the position of the thread and the elastic deformation due to the stress, the meshing surface of the external thread and the internal thread due to the stress at the position in advance at the meshing surface between the threads of the external thread and the internal thread is considered. A gap is formed in consideration of elongation and shrinkage of the male screw. When an external force (for example, internal pressure of a container) is applied to the screw, the gap is generated by the stress due to the external force. The gap formed was made equal over the entire length of the engagement between the female screw and the male screw.
[0020]
Although the details will be described with reference to FIG. 1, in the present invention, the gap between the meshing surfaces of the threads of the internal thread and the external thread is increased quadratically along the inner side of the container, so that the gap caused by the external force is generated. Therefore, the sum of the elongation of the screw and the shrinkage of the male screw is equal to the gap formed in advance.
[0021]
The reason for the above structure will be described with reference to FIGS. 1 to 4 showing an example of the embodiment according to the present invention and mathematical expressions.
Note that the present invention is not limited to only the embodiment shown in the drawings. Further, in order to avoid the numerical value of the calculation result becoming small, mm was used as a unit of length instead of m.
[0022]
FIG. 1 is a cross-sectional view of a screw portion of a screw-lid high-pressure container showing an example of an embodiment according to the present invention.
This corresponds to the portion B of the conventional screw cap type high pressure vessel 11 shown in FIG.
[0023]
The screw-cap-type high-pressure container 1 according to the present invention has the same configuration as the conventional screw-cap-type high-pressure container 11 shown in FIG. 6, and includes a container 2 and a disc-shaped high-pressure container that is screwed into an opening of the container 2 by rotating. A screw portion 4 is formed such that the inside of the opening of the container 2 and the outside of the screw cover 3 face each other and mesh with each other. Further, as shown in FIG. 4, a ring seal 7 provided on a portion of the screw lid 3 facing the inner wall of the container 2 so as to maintain the inside of the screw lid type high pressure container 1 at a high internal pressure P, A seal holding ring 8 for supporting the ring seal 7 from the inside of the screw cap 3 is provided.
[0024]
In the present invention, in the screw portion 4 shown in FIG. 1, the inner diameter of the screw 5 formed on the container 2 side is constant, and the outer diameter of the male screw 6 on the screw lid 3 side formed to mesh with the female screw 5. Is reduced in a quadratic function along the inward direction of the container 2 so that the gap between the meshing surfaces of the threads of the female screw and the external thread is quadratically defined along the inward direction of the container. Widened. The screw lid 3 having the male screw 6 is screwed into the container 2 having the female screw 5 to close the screw lid type high-pressure container 1.
[0025]
In FIG. 1, the trajectory 5a of the ridge and valley of the female thread and the trajectory 6a of the valley and valley of the male thread are shown by dashed lines in FIG. As can be seen from FIG. 1, for an internal thread 5 having the same internal diameter, the external diameter of the external thread 6 decreases along the inward direction of the container 2, and accordingly, the external threads of the internal thread and the external thread The gap between the engagement surfaces increases along the inside of the container 2.
[0026]
Here, in order to derive a mathematical expression for explanation having the above structure, symbols required for the mathematical expression are defined in FIG. The total length of the screw portion 4 is L, the base position of the screw portion 4 is L ₀ , the distal end position of the screw portion 4 is L _M , the pitch of the thread of the female screw 5 and the male screw 6 is p, and the flank angle (screw (Half angle of a mountain) is α. Further, the threaded portion 4 of the structure, at the position L _X distance X from the base end position L _0, the gap of the thread between the female thread 5 Tooneji 6 [delta] _L of the longitudinal _(axial), diameter the clearance of the thread between the direction of the female screw 5 Tooneji 6 and [delta] _D, the internal pressure P acting on the screw cap 3, the axial compressive stress generated in the axial direction tensile stress generated in the container 2 side sigma _N, the screw cap 3 Σ _B , ΔN represents the extension allowance on the female screw 5 side due to the axial tensile stress σ _N, and ΔB represents the shrinkage allowance on the male screw 6 side due to the axial compressive stress σ _B. Δ _L , δ _D , σ _N , σ _B , ΔN, ΔB are obtained using the above symbols and FIGS. 2 and 3.
[0027]
FIG. 2 is a cross-sectional view of the threaded portion showing a state where all the threads are engaged in the same manner under the load of the internal pressure P.
FIG. 3 is an enlarged sectional view of a portion A in FIG.
[0028]
Assuming that the internal pressure P acts on the screw cap type high-pressure vessel 1 and the same load is applied to all the threads in the screw portion 4 having the above structure, the longitudinal tensile stress σ _{N in} the length direction of the female screw 5 is linear. At the base position L ₀ of the screw portion 4 and becomes ₀ at the base position L _M of the screw portion 4.
_{σ N0 = P × π × (} D / 2) 2 / A N = (π × P × D 2/4) / A N
It becomes. Here sigma _N0 values of sigma _N in end position L _M of the threaded portion 4, A _N is the cross-sectional area of the internal thread 5 of the container 2, [pi is circle ratio, D is is the inner diameter of the container 2. From this equation, the axial tensile stress σ _N at any position L _X is
σ _N = σ _N0 × (X / L)
It becomes.
[0029]
On the other hand, the axial compressive stress sigma _B in the length direction of the male screw 6 side changes linearly, the tip position L _M at the proximal position L ₀ of the screw portion 4 0, threaded portion 4,
_{σ B0 = (π × P ×} D 2/4) / A B
It becomes. Here sigma _B0 value of sigma _B at proximal position L ₀ of the threaded portion 4, A _B is the cross-sectional area of the external thread 6 of the screw cap 3. From this equation, the axial compressive stress σ _B at any position L _X is
σ _B = σ _B0 × (X / L)
It becomes.
[0030]
At an arbitrary position L _X, elongation of the internal thread 5 between the positions L ₀ ~L _X, i.e., elongation allowance ΔN longitudinal needed as clearance,
ΔN = ∫σ _N × (1 / E _N ) dx = ∫σ _N0 × (X / L) × (1 / E _N ) dx
= (Σ _N0 × X ² ) / (2 × E _N × L)
It becomes. Where _{E N} is the Young's modulus of the female screw 5 (vessel 2).
[0031]
Similarly, at any position L _X, shrinkage of the external thread 6 between the positions L ₀ ~L _X, that is, contraction potential ΔB longitudinal needed as clearance,
ΔB = (σ _B0 × X ² ) / (2 × E _B × L)
It becomes. Here is a Young's modulus of _{E B} Waoneji 6 (screw cap 3).
[0032]
From the above equation, the sum of the extension allowance ΔN on the female screw 6 side and the contraction allowance ΔB on the male screw 6 side, that is, the required clearance δ _{L in the} length direction is δ _L = ΔN + ΔB.
= (Σ _N0 / (2 × E _N × L) + σ _B0 / (2 × E _B × L)) × X ²
It becomes. If E is N _{= E} B = _E (internal thread and external thread of the Young's modulus is the same), the above equation is as follows.
δ _L = ΔN + ΔB = X ² × (σ _N0 + σ _B0 ) / (2 × E × L)
As can be seen from the above expression, (σ _N0 / (2 × E _N × L) + σ _B0 / (2 × E _B × L)) or (σ _N0 + σ _B0 ) / (2 × E × L) is constant. since there, the relationship between the distance X from the proximal position L ₀ in the longitudinal direction of the gap [delta] _L and the threaded portion 4 is proportional to the square of the X, it can be seen that a quadratic function.
[0033]
As shown in FIG. 3, when the pitch p of the female screw 5 and the male screw 6 is equal to the flank angle α, the gap δ _L = ΔN + ΔB in the length direction is in the diameter direction (in the length direction) proportional to the flank angle α. It will produce a gap [delta] _D of the vertical direction). This diametric gap δ _D is
the _{δ D = δ L × cotα =} {X 2 × (σ N0 + σ B0) / (2 × E × L)} × cotα. Above relationship also, since cotα is constant, the relationship between the distance X from the proximal position L ₀ of the diametral clearance [delta] _D and the threaded portion 4, in proportion to the square of X, and a quadratic function It turns out that it becomes. That is, with respect to the longitudinal direction of the threaded portion 4, also the gap [delta] _D in the diameter direction with the length direction of the gap [delta] _L, increases in proportion to the square of the distance X from the proximal position L ₀ of the screw portion 4 And a quadratic function of the distance X.
[0034]
Therefore, according to the above relational expression, in the present invention, when the internal pressure P acts on the container 2, it is possible to prevent the concentration of the load on the screw portion 4 and to disperse the load. as a gap relative to the internal thread 5 of the container 2, the same pitch p and the male screw 6 of the screw cap 3 of the same flank angle alpha, advance a gap [delta] _L of the longitudinal direction of the threaded portion 4, the screw portion 4 was processed so as to reduce the radius of only thread diameter direction of the gap [delta] _D.
[0035]
Since the threaded portion 4 has the above structure, by forming a gap [delta] _L and diameter direction of the gap [delta] _D of suitable length direction, at the time of high pressure operation, the load applied to the internal thread 5 and the external thread 6 by the pressure P However, the screw-lid high-pressure vessel 1 can be configured so that the screw cap-type high-pressure container 1 is uniformly dispersed over the entire length of the engagement between the female screw 5 and the male screw 6. Therefore, when using a screw-cap high-pressure vessel 1 according to the present invention, when gradually applying pressure to the container 2, at a predetermined internal pressure P set, due to the gap [delta] _L and the internal pressure P in the longitudinal direction of the preformed The sum of the actual elongation ΔN of the female screw 5 and the shrinkage ΔB of the male screw 6 becomes equal, all the threads of the female screw 5 and the male screw 6 are uniformly meshed, and the load due to the internal pressure P is reduced by the internal screw P and the male screw 5. It is evenly distributed over the entire length of the screw 6 meshing.
[0036]
If the male screw 6 of the structure, differ at the meshing surface of each thread of the female screw 5 Tooneji 6, how under a load in the thread diameter direction of the gap [delta] _D Gaoneji 6 Is a problem. For example, when larger than the pitch p of the diameter direction of the gap [delta] _D screw mountain, with the area receiving the load becomes smaller with each other, inevitably subjected to a load at a portion near the summit of the threads to one another, the threads The load applied to itself acts as a moment force biased toward the crest of the thread. In this case, the rigidity of the thread itself cannot withstand the moment force, and the thread or the thread may be broken.
[0037]
However, the gap [delta] _D of the diameter direction conversely, if sufficiently small compared to the pitch p of the thread, since the gap [delta] _D in the diameter direction with respect to the height of the thread is also sufficiently small, each area receive the load from each other screws The loads are considered to be equal in the ridges, and the loads applied to the respective threads are also considered to be the same, and the load distribution in the screw portion 4 can be regarded as uniform. In this case, the stiffness of each thread itself is considered to be substantially equal.
[0038]
In order to verify the above state, as one example, E = 2 × 10 ⁵ N / mm ² , L = 300 mm, σ _B0 = 200 N / mm ² , σ _N0 = 100 N / mm ² , α = 30 °, and p = 15 mm. , And the case where X = L is calculated. In this case, the radial gap δ _D is
δ _D = L × (σ _B0 + σ _N0 ) × cotα / (2 × E)
= 300 × (200 + 100) × cot 30 ° / (2 × 2 × 10 ⁵ )
= 0.398mm
It becomes. Since the pitch p of the thread is 15 mm,
δ _D /p=0.389/15=0.026
Next, since the gap [delta] _D of the diameter direction sufficiently small with respect to the pitch p of the thread, the load distribution of a screw portion 4 can be regarded as uniform.
[0039]
FIG. 4 is a diagram showing both the cross section and the load distribution of the screw portion of the screw-lid high-pressure container which is an example of the embodiment according to the present invention.
[0040]
The load distribution shown in FIG. 4 is also similar to the load distribution shown in FIG. 7, in the screw cap type high-pressure container 1 having the above structure, when the internal pressure P is applied inside the container 2. It shows the load in the length direction, the load value is measured at evenly spaced positions of the screw portion 4, and the load value is used as a coefficient with respect to the average load, and the distribution in the length direction of the screw portion 4 is shown. is there. Here, in order to compare with the conventional screw lid type high pressure vessel 11 shown in FIG. 7, the measurement was performed under the same conditions as the conventional one.
[0041]
As shown in FIG. 4, in the screw-top high-pressure container 1 having the above-described structure, the load is uniformly applied at the average load level over the entire length of the screw portion 4, preventing the concentration of the load on the local portion and preventing the peak from being concentrated. The load on the part can be reduced. Also, it can be seen that the maximum load is about 1/5 as compared with the conventional screw-cap high-pressure container 11.
[0042]
FIG. 5 is a graph showing the relationship between the magnitude of the internal stress generated in the high-pressure vessel and the allowable number of repetitions of the stress generation, and is a well-known one published by the Japan High Pressure Technology Association or the like.
This graph uses a high-pressure container having a Young's modulus E _{350 of} 1.73 × 10 ⁵ N / mm ^{2 at} a use temperature of 350 ° C. It should be noted that mm is used as a unit of length depending on the size of the numerical value to be displayed.
[0043]
In the graph of FIG. 5, when the stress generated by the load in the conventional screw-cap high-pressure container 11 and the screw-cap high-pressure container 1 according to the present invention is compared, the generated stress amplitude in the conventional device is 686 N / mm ^2. (70 kgf / mm ² ) and the allowable number of repetitions of the generated stress is 1,000, whereas in the apparatus according to the present invention, the generated stress amplitude is significantly reduced to a level of 196 N / mm ² (20 kgf / mm ² ) or less. It can be seen that the allowable number of repetitions of the generated stress is 10 ⁷ = 10000000 times, and the life of the device can be significantly extended.
[0044]
【The invention's effect】
According to the first or second aspect of the invention, the container has a container and a screw cap screwed into the opening of the container, and is formed at the opening of the container so as to mesh with the female screw. Since the gap between the screw cap and the male screw is formed in advance so as to increase quadratically along the inside of the container, the load applied to the screw part is reduced by the length of the screw part. Since the load can be uniformly applied in the direction, load concentration can be prevented, metal fatigue can be reduced, and the life of the screw portion can be extended. Also, the screw length can be made shorter and compact, and if the screw length is the same, the load at the peak part is about 1/5 compared to the conventional parallel screw, and the metal fatigue It is possible to make the design area difficult to perform, and the life of the device can be greatly extended.
[0045]
According to the invention according to claims 3 to 5, the load applied to the male screw and the female screw due to the predetermined internal pressure of the container is evenly distributed over the entire length of the engagement between the female screw and the male screw. As described above, since the gap is set, the load on the screw portion with respect to the predetermined internal pressure of the container can be uniformly distributed in the length direction of the screw portion, so that the load concentration at the predetermined internal pressure is prevented, and metal fatigue is reduced. The length can be reduced and the life of the threaded portion can be extended.
[Brief description of the drawings]
FIG. 1 is a sectional view of a screw portion of a screw-top high-pressure container showing an example of an embodiment according to the present invention.
FIG. 2 is a cross-sectional view of a threaded portion showing a state in which a load of an internal pressure P is received and all threads are meshed in the same manner.
FIG. 3 is an enlarged sectional view of a portion A in FIG.
FIG. 4 is a diagram showing a cross section and a load distribution of a screw portion of a screw-top high-pressure container which is an example of an embodiment according to the present invention.
FIG. 5 is a graph showing a relationship between the intensity of stress generated in the high-pressure vessel and the allowable number of repetitions of the generated stress.
FIG. 6 is a cross-sectional view showing an example of a conventional screw cap type high pressure container.
FIG. 7 is a diagram showing a cross section and a load distribution of a screw portion in which a portion B in FIG. 6 is enlarged and turned sideways.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Screw lid type high pressure container 2 Container 3 Screw lid 4 Thread part 5 Female screw 6 Male screw 7 Ring seal 8 Seal holding ring

Claims (5)

In a container, a screw-lid high-pressure container having a screw lid screwed into an opening of the container,
The gap formed between the screw formed in the opening of the container and the male screw formed in the screw cap so as to mesh with the female screw is increased quadratically along the inside direction of the container. Thus, a screw-lid high-pressure container characterized by being formed in advance. The screw-lid high-pressure container according to claim 1,
A screw-lid high-pressure container characterized in that the internal diameter of the female screw is constant and the external diameter of the male screw is reduced in a quadratic function along the inside of the container in order to provide the gap. 3. The screw-lid high-pressure container according to claim 1, wherein a load applied to the male screw and the female screw by a predetermined internal pressure of the container is uniform over the entire length of the engagement between the female screw and the male screw. The screw gap type high pressure vessel, wherein the gap is set so as to be dispersed in the container. The screw-lid high-pressure container according to claim 3,
Due to a predetermined internal pressure of the container, the sum of the lengthwise elongation of the female screw and the contraction of the male screw in the lengthwise direction is formed in advance over the entire length of engagement of the female screw and the male screw. A screw-lid high-pressure container characterized by being equal to a gap. The screw-lid high-pressure container according to claim 4,
The quadratic function representing the gap is represented by the following equation.
_{δ L = (σ N0 / (} 2 × E N × L) + σ B0 / (2 × E B × L)) × X 2
Here, δ _L is a gap in the length direction of the female screw and the male screw, σ _N0 is an axial tensile stress at the innermost end of the female screw due to the internal pressure of the container, and σ _B0 is a value according to the internal pressure of the container. axial compressive stress at the deepest end of the external thread, X is the distance from the meshing proximal position of the said internal thread the external thread, the E _N Young's modulus of the internal thread, E _B is the external thread Young's modulus, L is the length of the internal thread and the external thread.

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