JPH0427463B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to an improvement in an air intake device applied to an expansion engine or the like.

[Prior art and its problems]

Conventionally, some gas liquefaction apparatuses are equipped with an expansion engine that cools gas by utilizing an adiabatic expansion phenomenon and recovers a part 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 to communicate the inside of the valve case 4 and the inside of the cylinder 1. 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 10 is always pressed against the outer surface of the valve seat 3 so as to close the valve port 5.

Furthermore, a cylindrical core 11 that is slidably supported on the inner surface of the valve body 8 is accommodated within 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. Further, since the inside of the cylinder 2 is maintained at a low pressure state after the gas is expanded, the valve body 8 is connected to the inside of the valve case 4 and the cylinder 2.
The valve seat 3 is pressed against the valve seat 3 by the pressure difference between the inside and the restoring force of the first coil spring 10, thereby keeping the valve port 5 in a closed state. 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 high pressure gas in the valve case 4 flows into the cylinder 2 through the notch 17 and the valve port 5. The pressure difference between the inside and the cylinder 2 becomes smaller. For this reason,
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 seat 3 are separated. The gap between the cylinders 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. The restoring force of the second coil spring 13 is the first
Since the energy to compress the first coil spring 10 is consumed, the valve body 8 moves a certain distance in the direction of compressing the first coil spring 10 and then stops.
Next, 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, the piston 1 is moving from the top dead center toward the 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
remains in pressure contact with the valve seat 3, 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.

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 8 during compression, and the coil spring 13 contacts the core 11 or the valve 8 during compression. Fatigue fracture occurred due to scratches.

[Purpose of the invention]

The present invention was made in order to solve the above-mentioned problems of the conventional device, and is suitable for use in expansion engines, etc., which are small, have no sliding parts, have a long life, are highly reliable, and are easy to manufacture. The purpose is to provide equipment.

[Summary of the invention]

The intake device for an expansion engine of the present invention includes a valve case that is provided at the head of a cylinder that slidably accommodates a piston for power extraction inside and is connected to a high-pressure gas supply system, and a valve case that connects the valve case and the cylinder. a valve seat provided in between and having a valve port that communicates the inside of the valve case with the inside of the cylinder; a valve body provided in the valve case for opening and closing the valve port; and a valve seat provided in parallel with the valve body. a first rod-shaped relay movable body; at least one pair of first spring washer-like springs having one end fixed to the inner wall of the valve case and the other end fixed to the relay movable body; and one end fixed to the valve case. fixed to the outer peripheral surface of the body, the other end is fixed to the relay movable body, the spiral direction is opposite to the spiral direction of the first spring washer-like spring, and the first spring washer is fixed to the outer peripheral surface of the body; at least one pair of second spring washer-like springs installed corresponding to the springs; and when the piston approaches the valve body within a predetermined distance, the moving force of the piston is applied to the valve body. an opening force transmission mechanism that transmits the opening force as an opening force, and this opening force transmission mechanism has a core, and a rod-shaped second movable relay body is provided parallel to the core, and the opening force transmission mechanism has an inner wall that At least one pair of third spring washer springs are provided, one end of which is fixed and the other end of which is fixed to the relay movable body, one end of which is fixed to the outer peripheral surface of the core, and the other end of which is fixed to the relay movable body. at least one pair of springs fixed to the movable body, the spiral direction of which is opposite to the spiral direction of the third spring washer-like spring, and which is installed in correspondence with the third spring washer-like spring; It is characterized by the provision of 4 spring washer-like springs.

〔Effect of the invention〕

If the intake device according to the present invention is used, there are no sliding parts, so normal long-term operation is possible, and high-precision machining such as sliding surfaces is not required, making the intake device applicable to highly reliable expansion engines, etc. A device is obtained. In particular, it is extremely useful as an intake device used in environments where lubrication is impossible at extremely low temperatures, such as in expansion engines of helium gas liquefaction systems.

[Embodiments of the invention]

An embodiment in which the intake device of the present invention is applied to an expansion engine will be described with reference to FIGS. 2 and 3. FIG. 2 is a principle diagram of the function of a combination spring used in the intake device of an expansion engine according to the present invention. Reference numeral 22 denotes a rod-shaped movable body, and as means for moving this movable body 22 in the Z-axis direction, springs 21a, 21b, 29a, 29b in the form of spring washers and a relay movable body 20 in the form of a rod are used. That is, one end of the spring washer-like springs 29a, 29b is held at rest 28.
Further, one end of the spring washer-like springs 21a, 21b is fixed to the movable body 22, and the other end is fixed to the relay movable body 20. The spiral directions 23a and 23b of the spring washer springs 21a and 21b correspond to the spiral directions 24a and 23b of the spring washer springs 29a and 29b, respectively.
It is installed so that it faces oppositely to 24b.
The movable body 22 is a spring washer-like spring 29
a, 29b, 21a, and 21b, and the relay movable body 20 is disposed parallel to the movable body 22. In addition, the spring washer type spring 2
1a, 21b, 29a, 29b have the same bending strength,
It is necessary to have 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 (20 in FIG. 2), the spring washers 29a and 29b are deformed out of plane, so that the movable body moves in the Z direction in parallel to the Z axis. When the movable body and the stationary part are displaced, they are also displaced in the radial direction (R direction) and circumferential direction (θ direction), and if the gap between the movable body and the stationary part is not set large, they will come into contact.
On the other hand, as shown in FIG.
The direction of the spiral 23a, 2 is opposite to that of a, 24b.
3b, a spring washer-like spring 21a,
21b, when a force in the Z direction is applied to the movable body 22, the relay movable body 20 will act as described above.
Although it is displaced in the R direction and the θ direction as well as the Z direction,
The movable body 22 simply displaces linearly in the Z direction;
There is no displacement in the θ direction. Therefore, the relative displacement between the movable body 22 and the stationary part is the same as that of the spring washers 21a and 21b for the same acting force.
This is twice as much as without it. In other words, the allowable stroke of the movable body, which is determined under the condition that the spring does not undergo plastic deformation or breakage, can be doubled.

Although the spring washer-like springs are arranged in the order of 29a, 21a, 21b, and 29b in FIG. 2, 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. 2, 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 2b
By making the vicinity of the end 31 of the spring washer-like spring 30 multi-layered in a step-like manner as shown in FIG. .

FIG. 3 is a sectional view showing a schematic configuration of an intake device for an expansion engine according to an embodiment of the present invention, and FIG.
The same parts as those in the figures are indicated 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 and 34b are provided, and one end parallel to the valve seat 3 is fixed to the inner wall of the valve case and the other end is fixed to the relayable body 35.
Pair of spring washers 33a, 33b
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,
It is pressed against the valve seat 3 by the elastic force of 34a, 34b and the pressure difference between the inside of the valve case 4 and the inside of the cylinder 2. When the piston 1 approaches near the top dead center, the moving force of the piston 1 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 bent and elastic energy is accumulated. . And piston 1
Immediately before reaching 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, 37
The elastic energy accumulated in a 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 high pressure gas flows into the cylinder 2.
The valve body 8 is a spring washer-like spring 36
a, 36b, 37a, 37b move to the right in the figure due to the restoring force, and the kinetic energy is transferred to the spring washer-like springs 33a, 33b, 34a, 34.
It stops when the elastic energy becomes almost equal to the elastic energy of b, and then the spring washer springs 33a,
By releasing the elastic energy accumulated in 33b, 34a, 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.

[Other embodiments of the invention]

FIG. 4 is a sectional view showing a schematic configuration of an intake system for an expansion engine according to an embodiment of the present invention, and the same parts in FIG. 3 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 37 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.
a and 37b are provided. and,
Attached to the upper end of the core 11 is one end of a rod 16a having a length that passes through the valve port 5 and reaches into the valve case 4. 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. 3, 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 embodiments show examples in which the intake device of the present invention is applied to an expansion engine, it is clear that the present invention is not limited to this and can also be used as a general intake device. .

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a conventional intake device, FIG. 2 is a perspective view showing the structure of a combination spring that supports a valve body and a core in the present invention, and FIG. 3 is a sectional view showing an embodiment of the present invention. 4 are sectional views showing other embodiments of the present invention. 1... Piston, 2... Cylinder, 4... Valve case, 8... Valve body, 11... Core, 33a, 33b, 3
4a, 34b, 36a, 36b, 37a, 37b
...Spring washer-like spring, 35, 38... Relay movable body, 41... Opening force transmission mechanism.

Claims (1)

[Scope of Claims] 1. A valve body movably supported to open and close a valve port formed near the head of the cylinder to enable communication between the inside of the cylinder and a gas supply system; and this valve body. a valve body support mechanism that supports the valve body so as to be able to reciprocate in a predetermined direction; An intake device comprising: a movably supported core for transmitting opening force to the valve body; and a core support mechanism that supports the core so as to be movable back and forth in a predetermined direction, wherein the valve body support mechanism is , a first elastic support member that supports the first relay member movably in the opening and closing direction of the valve body relative to the cylinder stationary part; and a first elastic support member that supports the first relay member movably in the opening and closing direction of the valve body relative to the first relay member; a second elastic support member that movably supports the valve body, and the first and second elastic support members support the first and second elastic support members when an opening/closing force is applied to the valve body. Each deformation in a direction different from the opening/closing direction of the valve body generated in the member is substantially opposite to each other and has a substantially equal magnitude, and is configured to cancel each other out, and an opening/closing force is applied to the valve body. In some cases, the valve body is configured to be displaced only in the opening/closing direction, and the core support mechanism includes a third relay member that supports the second relay member so as to be movable in a predetermined direction with respect to the valve body or the piston. and a fourth elastic support member that supports the core movably in a predetermined direction with respect to the second relay member, and the third and fourth elastic support members are When the opening/closing force of the valve body acts on the core, the third
and a fourth elastic support member, the respective deformations 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 intake device characterized in that the core is configured to be displaced only in a predetermined direction when an opening/closing force of the valve body is applied to 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 member to the stationary portion is different from the shape of the second elastic support member. a shape of the elastic support member from the valve body to the relay member;
The shape of the second elastic support member from the valve body to the relay member is different from the first and second elastic support members.
The third and fourth elastic support members are arranged in an opposite relationship so that deformations of the elastic support members in directions other than the opening and closing directions of the valve body cancel each other out, and the third and fourth elastic support members are formed of the same material and have substantially the same shape. , the shape of the third elastic support member from the relay member to the valve body or the piston, and the shape of the fourth elastic support member from the core to the relay member, The intake air according to claim 1, wherein the third and fourth elastic support members are arranged in an opposite relationship so that deformations of the core in a direction other than a predetermined movement direction cancel each other out. Device. 3. The first and second elastic support members are both composed of first and second spring washer-like springs in a one-to-one relationship, and the first and second elastic support members
The spiral directions of the spring washer-like springs are arranged in opposite directions to mutually cancel out the deformation of the first and second spring washer-like springs in directions other than the opening/closing direction of the valve body,
The third and fourth elastic support members are each composed of a pair of third and fourth spring washer-like springs, and the helical directions of the third and fourth spring washer-like springs are fixed. Claim 1, characterized in that deformations of the third and fourth spring washer springs in directions other than a predetermined movement direction of the core are canceled out by arranging the springs in opposite directions. Intake device as described.