JPH0559341B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an improvement in a valve body opening/closing device applied to an intake device or the like used in an expansion engine or the like.

(Prior Art) Conventionally, some gas liquefaction devices are equipped with an expansion engine that cools the gas by utilizing the adiabatic expansion phenomenon and recovers a portion of the expansion energy at that time. . Among the expansion engines used for the above-mentioned purposes, there are known ones that are equipped with an intake device that opens and closes intake valves without using a cam.

The intake system for an expansion engine that opens and closes an intake valve without using a cam as described above is generally constructed as shown in FIG. That is, the head wall of the cylinder 2 which slidably accommodates the piston 1 is used as a valve seat, and the cylinder 2 is mounted on the outer surface of the valve seat 3.
A cylindrical valve case 4 is attached coaxially with the valve seat 3, and a valve port 5 is provided in the center of the valve seat 3 for communicating the inside of the valve case 4 and the inside of the cylinder 2. A wall 6 facing the valve port 5 of the valve case 4
A gas inlet 7 is provided in the gas inlet 7, and this gas inlet 7 is connected to a high pressure gas source (not shown). A cylindrical valve body 8 with a bottom for selectively closing the valve port 5 is housed in the valve case 4 with its open end facing the valve seat 3 side. The outer surface of the valve body 8 has protrusions 9 provided radially on its outer periphery and is slidably supported on the inner surface of the valve case 4, and is inserted between the protrusions 9 and the wall 6. A first coil spring 1 is always pressed against the outer surface of the valve seat 3 so as to close the valve port 5.

Furthermore, a core 11 formed in a cylindrical shape and slidably supported on the inner surface of the valve body 8 is accommodated in the valve body 8 . A second coil spring 13 is inserted between the core 11 and the so-called bottom wall 12 of the valve body 8, and the restoring force of the second coil spring 13 causes the core 11 to move toward the valve body 8. It is pressed into contact with the opening of the body 8 in such a manner that the opening is closed from the inside. Furthermore, in the core 11,
A rod 16a long enough to penetrate the opening of the valve body 8 and the valve port 5 to reach the inside of the cylinder 2, and a rod 16b long enough to reach near the bottom wall 12 of the valve body 8 are attached. . Note that 17 in the figure indicates a notch for gas flow. Further, an exhaust device is omitted.

The intake system of an expansion engine having such a configuration operates as follows.

First, while the piston 1 in the cylinder 2 is moving from the bottom dead center to the vicinity of the top dead center, the inside of the valve case 4 is maintained at a high pressure by the high pressure gas flowing in from the inlet 7. Also, since the inside of cylinder 2 is kept at a low pressure after the gas expands,
The valve body 8 is pressed against the valve seat 3 by the pressure difference between the inside of the valve case 4 and the inside of the cylinder 2 and the restoring force of the first coil spring 10, thereby closing the valve port 5. It is becoming. However, piston 1
When the piston 1 moves to the vicinity of the top dead center, the piston 1 contacts the rod 16a attached to the core 11.
The core 11 slides within the valve body 8 while compressing the second coil spring 13 while moving to just before the top dead center while making contact. When the piston 1 reaches just before the top dead center, the rod 16b of the core 11 comes into contact with the inner surface of the bottom wall 12 of the valve body 8, causing the valve body 8 to move slightly to the right in the figure. As a result, a minute gap is created between the valve body 8 and the valve seat 3, and the valve case 4
The high-pressure gas inside flows into the cylinder 2 through the notch 17 and the valve port 5, and the pressure difference between the valve case 4 and the cylinder 2 becomes small. Therefore, the valve body 8 slides inside the valve case toward the right in the figure due to the restoring force of the second coil spring 13, and immediately after the piston 1 reaches the top dead center, the valve body 8 and the valve The distance from the seat 3 increases, and a large amount of high pressure gas flows into the cylinder. As a result, the pressure within the cylinder 2 increases, and a force is applied to the piston to move it toward the bottom dead center. Since the restoring force of the second coil spring 13 is consumed by the energy to compress the first coil spring 10, the valve body 8 stops after moving a certain distance in the direction of compressing the first coil spring 10, and then It moves in the opposite direction and presses against the valve seat 3 again to close the valve port 5. Note that at this point, piston 1
is moving from top dead center to bottom dead center. Therefore, while the piston 1 is moving toward the bottom dead center, the pressure inside the cylinder 2 decreases, and the valve body 8
The valve seat 3 is kept in pressure contact, and the valve port 5 is also kept closed. Through such a cycle, the gas flowing into the cylinder 2 is adiabatically expanded and cooled. The cooled gas is then discharged to the outside of the cylinder 2 by an exhaust device (not shown) while the piston 1 passes through the bottom dead center and moves to the top dead center.

(Problems to be Solved by the Invention) However, the intake device for an expansion engine configured as described above has the following problems.

In other words, in such an intake system, when operated for a long time, the sliding members may wear out or seize on the inner and outer sliding surfaces of the valve body 8, and the valve body 8 may not be able to open and close normally. Ta. In particular, when the intake device is used at extremely low temperatures, such as in a helium gas liquefaction system, the lubricating oil itself solidifies, making it impossible to lubricate the sliding parts with oil, making it extremely difficult to obtain stable sliding motion. It was difficult.

Furthermore, in order for the valve body 8 to slide smoothly, it was necessary to machine the sliding surface with extremely high precision. Furthermore, in a small intake device, the required deflection of the compression coil spring, especially the coil spring 13, is larger than the effective diameter, so buckling occurs, and the coil spring 13 comes into contact with the core 11 or the valve body 8 when compressed. The scratches caused fatigue fractures.

The present invention has been made in order to solve the above-mentioned problems of the conventional devices, and is an air intake device used in expansion engines, etc., which is small, has no sliding parts, has a long life, is highly reliable, and is easy to manufacture. The purpose of the present invention is to provide a valve body opening/closing device applicable to, etc.

[Structure of the invention]

(Means for Solving the Problems) The valve body opening/closing device of the present invention opens and closes a valve port formed near the head of the cylinder to enable communication between the inside of the cylinder and the gas supply system. a valve body for opening and closing the valve body, and a piston that moves within the cylinder to open and close the valve body, and is movable in order to transmit the moving force of the piston as an opening force of the valve body when the piston moves within a predetermined distance. A valve body opening/closing device comprising a valve body opening/closing mechanism having a core supported by the valve body, and a core support mechanism supporting the core so as to be reciprocally movable in a predetermined direction, wherein the core support mechanism includes: a first elastic support member that supports the movable relay body so as to be movable in a predetermined direction with respect to the body or the piston; and a second elastic support member that supports the core so as to be movable in a predetermined direction with respect to the movable relay body. a support member, the first and second elastic support members are configured to support the first elastic support member when the opening/closing force of the valve body acts on the core.
and the respective deformations generated in the second elastic support member in directions different from the predetermined movement direction of the core are substantially opposite to each other and have substantially the same magnitude, and are configured to cancel each other out, The present invention is characterized in that the core is configured to be displaced only in approximately a predetermined direction when the opening/closing force of the valve body acts on the core.

(Function) According to the valve body opening/closing device configured as described above, there is no sliding part, and the core for opening and closing the valve body can be displaced without being deformed in any direction other than a predetermined direction. Since the valve is supported by the first and second elastic support members so as to produce the following effects, the opening and closing operations of the valve are highly reliable.

(Embodiment) An embodiment in which the valve body opening/closing device of the present invention is applied to an intake device of an expansion engine will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram showing the principle of the function of a combination spring used in the intake device of an expansion engine according to the present invention. 22 is a rod-shaped movable body (corresponding to the core 11 in the expansion engine shown in FIG. 2), and as a means for moving this movable body 22 in the Z-axis direction in the figure, a rod-shaped relay movable body 20 and Spring washer-like springs 29a, 29b and 21a, 21b are used as examples of the first and second elastic support members.

That is, the spring washer spring 29
One end of a, 29b is connected to a stationary part (corresponding to cylinder 2 in the expansion engine shown in FIG. 2) 28a, 2
8b, and further, one end of the spring washer-like springs 21a, 21b is fixed to the movable body 22,
These spring washer springs 21a, 21
The other ends of each of b, 29a, and 29b are fixed to the movable relay body 20, respectively. Spiral direction of spring washer springs 21a, 21b, 23a, 2
3b is a spring washer-like spring 29, respectively.
It is installed so that the direction of the spirals 24a and 24b of a and 29b is opposite to that of the spirals 24a and 24b. The movable body 22 includes spring washer-like springs 29a, 29b, 21.
The relay movable body 20 is disposed on an axis connecting the centers of the movable bodies 21a and 21b, and the relay movable body 20 is disposed parallel to the moving direction of the movable body 22. In addition, the spring washer-like spring 21a,
It is necessary that 21b, 29a, and 29b have the same bending strength and the same torsional strength.

Here, a pair of spring washer springs 21
Consider a case where there are no a, 21b and the relay movable body 20 itself is a movable body. At this time, when a force in the Z direction is applied to the movable body (corresponding to 20 in FIG. 1), the spring washer-like springs 29a, 29b
deforms out of plane, the movable body is displaced in the Z direction parallel to the Z axis, and at the same time in the radial direction (R direction)
and is also displaced in the circumferential direction (θ direction),
If the distance between the movable body and the stationary part is not set large, they will contact each other. On the other hand, as shown in FIG.
When the spring washer-like springs 21a and 21b, denoted by a and 23b, are added, when a force is applied to the movable body 22 in the Z direction, the relay movable body 20 moves in the R direction and the θ direction as well as the Z direction, as described above. are also displaced, but the spring washer-like springs 21a, 21b and 29a, whose spiral directions are opposite to each other.
29b, the displacements in the R direction and the θ direction cancel each other out, so the movable body 22 is only linearly displaced in the Z direction and not in the R direction or the θ direction. Therefore, the relative displacement between the movable body 22 and the stationary part is twice that of the case without the spring washers 21a, 21b for the same acting force. In other words, the allowable stroke of the movable body determined under the condition that the spring does not undergo plastic deformation or breakage is 2.
Can be doubled.

Although the spring washer-like springs are arranged in the order of 29a, 21a, 21b, and 29b in FIG. 1, they may be arranged in the order of 29a, 21a, 29b, and 21b. Further, there may be a plurality of sets of these spring washer springs 21a, 21b, 29a, 29b. Furthermore, the spring washers 21a, 21b, 29a, 29b do not need to be springs with a rectangular cross section, and may have any cross-sectional shape other than a circular cross-section. Further, the spring washer-like spring is not limited to a single layer structure, but may be a multilayer structure. In FIG. 1, the shape of the spring is shown as a complete arc, but it may have any shape as long as it surrounds the movable body, such as a horseshoe shape. In short, spring washer-like springs 21a, 21b, 29
Both a and 29b have the same shape (same rigidity), that is, the same bending strength and the same torsional strength, and the spiral directions 23a, 23b of the spring washer-like springs 21a, 21b and the spring washer-like springs 29a, 29b. Direction of the spiral 24a, 24
It is sufficient if b are in opposite directions. Also, Figure 1b
By making the vicinity of the end 31 of the spring washer-like spring 30 multi-layered in a stepped manner as shown in the figure, it is possible to alleviate the stress concentration that occurs near the end 31 during deformation, and to prevent plastic deformation and breakage. .

FIG. 2 is a sectional view showing a schematic configuration of an air intake device for an expansion engine according to an embodiment of the present invention, and FIG.
Identical parts in the figures are designated by the same reference numerals. Therefore, the explanation of the overlapping parts will be omitted.

In this embodiment, the opening of the valve body 8 is connected to the valve seat 3.
A pair of springs parallel to the valve seat 3 are housed in the valve case 4 so as to be arranged on the sides, one end is fixed to the outer peripheral surface of the valve body 8, and the other end is fixed to the rod-shaped relay movable body 35. Washer-like springs 34a, 34b are provided, and a pair of spring washer-like springs 33a, 33b parallel to the valve seat 3 have one end fixed to the inner wall of the valve case and the other end fixed to the relay movable body 35.
and a spring washer-like spring 33
The directions of the spirals of springs a and 33b and the spirals of spring washers 34a and 34b are set to be opposite to each other, and the restoring force of these springs 33a, 33b, 34a and 34b allows the above-mentioned The valve body 8 is brought into pressure contact with the valve seat 3. An opening force transmission mechanism 41 is provided on the inner surface 40 of the valve body 8, and this opening force transmission mechanism 41 is configured as follows. A pair of spring washer-like springs 36a and 36b are provided parallel to the valve seat 3, one end of which is fixed to the inner surface 40 of the valve body 8, and the other end of which is fixed to the rod-shaped relay movable body 38. A pair of spring washer-like springs 37a, 37b are provided parallel to the valve seat 3, one end of which is fixed to the outer wall of the valve seat 11, and the other end is fixed to the relay movable body 38. The direction and the direction of the spirals of the spring washer springs 37a, 37b are set to be opposite to each other. The cylinder 2 is inserted through the valve port 5 on the surface of the core 11 facing the valve port 5.
One end of a rod 16a having a length reaching inside is attached.

With such a configuration, when the piston 1 is currently moving from the bottom dead center to the top dead center, the valve body 8
are spring washer-like springs 33a, 33b,
The valve seat 3 is pressed against the valve seat 3 by the elasticity of the valves 34a and 34b and the pressure difference between the valve case 4 and the cylinder 2. When the piston 1 approaches the vicinity of the bottom dead center, the moving force of the piston is transmitted to the opening force transmission mechanism 41. That is, while the piston 1 is in contact with the rod 16a and the rod 16a is moving toward the right in the figure, the spring washers 36a, 36b, 37a, and 37b are deflected and elastic energy is accumulated. Ru. Then, just before the piston 1 reaches the top dead center, the core 11 contacts the upper surface of the inner wall of the valve body 8, causing the valve body 8 to move slightly to the right in the figure. At this time, a minute gap is created between the valve body 8 and the valve seat 3, and the pressure difference between the inside of the valve case 4 and the inside of the cylinder 2 is reduced. When the pressure difference decreases, the spring washer-like springs 36a, 36b, 3
The elastic energy stored in 7a and 37b moves the valve body 8 further to the right in the figure, and the spring washer-like spring 33 supporting the valve body 8
It is consumed as energy for deflecting a, 33b, 34a, and 34b. Therefore, Benguchi 5
is opened and flows into the high pressure gas cylinder 2. The valve body 8 has a spring washer-like spring 36a,
It moves to the right in the figure due to the restoring force of 36b, 37a, 37b, and stops when its kinetic energy becomes approximately equal to the elastic energy of spring washer-like springs 33a, 33b, 34a, 34b,
After that, the spring washer springs 33a, 33
By releasing the elastic energy stored in b, 34a, and 34b, they move in the opposite direction, press against the valve seat 3 again, and close the valve port 5.

Therefore, the spring washer-like springs 33a, 33b, 34a, 34b and spring washer-like springs 36a, 36b, 37 used
If the material, plate thickness, and shape of a and 37b are determined in advance in consideration of the necessary amount of deflection, rigidity, etc., they can function well.

FIG. 3 is a sectional view showing a schematic configuration of an intake system for an expansion engine to which another embodiment of the valve body opening/closing device of the present invention is applied, and the same parts as in FIG. 2 are designated by the same reference numerals. Therefore, the explanation of the overlapping parts will be omitted.

In this embodiment, the opening transmission mechanism 41 is different from the previous embodiment. That is, the opening force transmission mechanism 41 in this embodiment has the following configuration. A recess 43 is provided in the center of the head 42 of the piston 1, the core 11 is accommodated in the recess 43, one end is fixed to the inner peripheral wall 44 of the recess 43, and the other end is fixed to the relay movable body 38. A pair of spring washer springs 36a, 36 parallel to the seat 3
b, and a pair of spring washer-like springs 37a, 3 parallel to the valve seat 3, one end of which is fixed to the peripheral wall of the core 11 and the other end of which is fixed to the relay movable body 38.
7b is provided. And the middle child 1
One end of a rod 16a having a length that passes through the valve port 5 and reaches inside the valve case 4 is attached to the upper end of the valve 1. Since the valve body 8 and the spring washer-like springs 33a, 33b, 34a, and 34b provided thereon are the same as those shown in FIG. 2, their explanation will be omitted.

With such a configuration, when the piston 1 approaches near the top dead center, the rod 16a provided in the recess 43 of the piston 1 comes into contact with the bottom surface of the valve body 8 through the valve port 5, and as a result, Move the valve body 8 slightly to the right in the figure. The subsequent operations are almost the same as those in the previous embodiment, and will therefore be omitted.

With the above configuration, the same effects as those of the above-mentioned embodiments can be obtained, and since the core 11 is provided inside the piston 1, the valve body 8 can be made smaller.

Although the above embodiment shows an example in which the valve body opening/closing device of the present invention is applied to an intake system of an expansion engine, the present invention is not limited to this and may be applied as a general valve body opening/closing device. It is obvious that it can be done.

〔Effect of the invention〕

If the valve body opening/closing device according to the present invention is used, there are no sliding parts, so the device can operate normally for a long time, and high-precision machining such as sliding surfaces is not required, resulting in highly reliable operating conditions. can get. In particular, it is extremely useful when applied to an intake device used in an atmosphere where lubrication is impossible at extremely low temperatures, such as an expansion engine of a helium gas liquefaction system.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the structure of a combination spring supporting the valve body and core in the present invention, Fig. 2 is a sectional view showing one embodiment of the present invention, and Fig. 3 is another embodiment of the present invention. A sectional view showing an example, FIG. 4 is a sectional view showing a conventional intake device. 1... Piston, 2... Cylinder, 11... Core, 2
9a, 29b, 37a, 37b...Spring washer spring (first elastic support member), 21a,
21b, 36a, 36b... Spring washer-like spring (second elastic support member), 38... Relay movable body, 41... Opening force transmission mechanism (valve body opening/closing mechanism).

Claims (1)

[Scope of Claims] 1. A valve body for opening and closing a valve port formed in the vicinity of the head of the cylinder to enable communication between the inside of the cylinder and a gas supply system; a valve body opening/closing mechanism having a movably supported core for transmitting the moving force of the piston as the opening force of the valve body when a piston moving within the cylinder approaches within a predetermined distance; A core support mechanism that supports a core so as to be able to reciprocate in a predetermined direction; and a valve body opening/closing device, wherein the core support mechanism supports a movable relay body in a predetermined direction with respect to the valve body or the piston. a first elastic support member that movably supports the core; and a second elastic support member that movably supports the core in a predetermined direction with respect to the relay movable body; The elastic support member is configured to support the first elastic support member when the opening/closing force of the valve body acts on the core.
and the respective deformations generated in the second elastic support member in directions different from the predetermined movement direction of the core are substantially opposite to each other and have substantially the same magnitude, and are configured to cancel each other out, An opening/closing device for a valve body, characterized in that the core is configured to be displaced only in approximately a predetermined direction when the opening/closing force of the valve body acts on the core. 2. The first and second elastic support members are made of the same material and have substantially the same shape, and the shape of the first elastic support member from the relay movable body to the valve body or the piston; The shape of the second elastic support member from the core to the relay movable body cancels out deformation of the core of the first and second elastic support members in a direction other than a predetermined movement direction. 2. The valve body opening/closing device according to claim 1, wherein the valve body opening/closing device is arranged in an inverse relationship so as to fit together. 3. The first and second elastic support members are both composed of a pair of first and second spring washer-like springs, and the spiral directions of the first and second spring washer-like springs are A patent claim characterized in that deformations of the first and second spring washer-like springs in directions other than a predetermined movement direction of the core are canceled out by arranging the springs in opposite directions. The valve body opening/closing device according to item 1.