JPS61228260A - Suction valve for expansion machine - 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 [Field of Industrial Application] The present invention relates to an intake valve of a reciprocating expander used in a He gas liquefaction system or the like.

[Prior Art] Conventionally, in this type of expander, in order to open and close the suction and exhaust ports of the expansion chamber at predetermined timing, the suction and exhaust ports on the low temperature side are connected from the piston drive source on the normal temperature side through a cam mechanism, etc. The movement was transmitted to the valves, and the valve bodies were driven in synchronization with the expander cycle. However, such a system has drawbacks such as the need to extend a long driving rod through a heat insulating vacuum layer around the expander, making the valve driving mechanism complicated and large.

Therefore, in order to avoid such structural complexity, efforts are being made to make it possible to directly drive the valve body using an internal mechanism, rather than mechanically driving the valve body from an external drive source. However, in recent years, intake valves have been designed to automatically open and close the intake port by driving a valve body by the movement of a piston, such as the one shown in Japanese Patent Application Laid-Open No. 56-44556. has been devised.

That is, the structure shown in FIG. 6 disclosed in the same publication has a schematic structure in which a cylinder body A is provided with a communication hole (intake port) C and a cylinder body B (a first cylinder body Ba and a first cylinder body B) are connected to each other. 2
Inside the cylindrical body Bb), there are provided a valve E that closes the communication hole C, and an abutment body F that protrudes from the communication hole C so as to be able to move forward and backward into the cylinder body A, and is slidably held within the cylinder body A. A cylindrical valve body D (a first cylinder Da and a second cylinder Db) having a second spring I having a stronger spring force than the first spring G that urges the abutting body F toward the piston H on the inner periphery of the valve body; A slide stopper J for the abutting body F is provided in the cylindrical body B. In this case, during the exhaust process when the piston H approaches the top side of the cylinder,
First, the piston H contacts the contact body F and pushes down only the relevant contact body F. Then, when this contacts the stopper J near the top dead center of the piston H, the entire valve body is pushed down and the intake port C is automatically closed. It will be developed in the future. Also, when the valve E opens and moves to the intake process, the cylinder internal pressure and the port internal pressure are balanced, and the second spring I in the valve body
is dominant, so the valve remains open until the abutting body F comes into direct contact with the valve body within the valve body, and then wS
The restoring force of the spring G of No. 1 causes the entire valve body to rise, and the valve E comes into contact with a predetermined valve seat.

Here, the exhaust bow) C is automatically closed. Therefore, with this kind of device, there is no need to attach a separate drive mechanism from the outside to drive the valve body as in the past, which is convenient in terms of simplifying the structure of the expander as a whole. I can say that.

However, the problem with the above configuration is that the structure inside the cylinder (the top of the cylinder) connected to the cylinder body is complicated and large. In other words, an elongated cylindrical body is connected to the cylinder body, and members such as first and second cylindrical bodies, abutting bodies, and first and second springs are fitted into the cylindrical body in a predetermined manner. The problem is that it must be assembled under certain conditions, and that two different types of springs must be prepared and the spring strengths of these springs must be delicately balanced. For this reason, the production cost is high, the assembly work is troublesome, and furthermore, it remains a practical problem that it cannot sufficiently meet the demands for compactness for integration into a small expander.

[Problems that Haimei is trying to solve] Akira Kigata has improved the above valve mechanism in order to overcome the above problems. The mechanism has a small number of parts (particularly, only one spring is required), and its structure is simple and easy to assemble, and at the same time, it can be incorporated into the expander compactly without occupying extra space. The purpose of the present invention is to provide a new intake valve for an expander that can be used in an expander.

[Means for Solving the Problems] In order to achieve this purpose, Kin Yanmei installed an intake port at the top of the cylinder of a reciprocating expander, and one end of the intake port was connected to the A valve body is irremovably inserted into the expansion chamber so as to be able to move forward and backward into the expansion chamber and close the intake port when it is displaced toward the piston, and is biased from the top of the cylinder toward the piston through a spring. At the same time, a piston abutting body having a larger protrusion height into the expansion chamber than the valve body is provided so as to protrude from the storage hole at the top of the cylinder so as to be able to move forward and backward. The piston contacting body is latched by the valve body to prevent displacement of the piston contacting body beyond a certain level toward the piston side when the piston abutting body advances and extends into the expansion chamber following the end face of the piston. It is.

[Effect] That is, if the intake valve has such a configuration.

By simply installing a valve body and a piston abutting body on the top side of the cylinder under predetermined simple installation conditions, the intake port provided at the top of the cylinder can be automatically opened and closed at the required timing as the piston reciprocates. can. In other words, according to the present invention, when the piston approaches the top of the cylinder during the exhaust process, the piston first contacts the piston abutting body with a large protruding height and gradually retracts the abutting body into the storage hole. Then, the piston comes into contact with a valve body whose one end protrudes into the expansion chamber, and together with the piston abutting body, pushes the valve body away from the piston.

Then, near the top dead center of the piston at the end of the exhaust process, the valve body is displaced to the valve closing position on the opposite side of the piston, and at this time the intake port is automatically opened. During the intake process in which the piston moves away from the piston, the piston contact body is urged by the spring and moves into the expansion chamber to follow the piston end surface, while the valve body is forced to move between the expansion chamber pressure and the intake port internal pressure. The valve remains balanced for a while and remains open. If this state is maintained and the piston abutting body advances or extends beyond a certain level toward the piston, the abutting body will be latched to the valve body and will be prevented from further displacement; The spring force of the spring that biases the piston abutting body is applied to the valve body, and as a result, the valve body is forcibly displaced toward the piston and at the same time automatically closes the intake port. It turns out.

[Example] Hereinafter, an example of the tree 4eLBA will be described with reference to the drawings.

Figures 1 to 3 are a reciprocating type expander according to one production process, more specifically, a configuration of main parts on the low temperature side of an expander used in a Claude cycle refrigerator. ,
Reference numeral 1 denotes a cylinder having a cylindrical body with a bottom. A piston 2 is slidably fitted into the cylinder 1, and an expansion chamber is formed between the piston 2 and the opposing cylinder top 1a, which expands and contracts with the reciprocation of the piston 1. 3 is formed. The cylinder top portion 1a is provided with an intake port 4 (high pressure port) that opens at the center thereof. This intake port 4
The intake port 4 is located inside the cylinder top portion 1a provided with the intake port 4.
A valve chamber 5 containing a valve body is provided in communication with the valve body, and a valve seat 6 on which the valve body comes into contact is formed on the piston-side slope of the valve chamber 5. And this intake port 4
A valve body 7 is inserted inside the valve body. As shown in FIG. 2, the valve body 7 includes a bell-shaped valve body 7a that is contained in the valve chamber 5 and abuts against the valve seat 6 to close the intake port 4, and a bell-shaped valve body 7a that closes the intake port 4. The hanging piece 7b is formed separately and consists of a planar cross-shaped hanging piece 7b that projects into the chamber 3, and a rod part 7C that is loosely fitted into the intake port 4 and connects both ends of the hanging piece 7b. 7b is fixed to the rod portion 7C with screws 7d, etc., and assembled into a single piece. The main body 7a and the locking piece 7b of the valve body 7 serve as a stopper to prevent escape in the axial direction, and the locking piece projects into the expansion chamber 3 only with a certain stroke. 7b is movable back and forth, and when the valve body 7 as a whole is displaced toward the piston, its main body 7a comes into contact with the valve seat 6 to close the intake port 4, and conversely, it is displaced toward the opposite side of the piston. When the main body 7
a is configured to separate from the valve seat 6 and open the intake port 4. In addition, in the valve open state, each part of the valve body 7 is designed to provide a sufficient gap with the opposing member so that the inflow of the working gas is not obstructed.

Furthermore, a cylindrical piston abutment body 8 is provided at the top portion 1a of the cylinder from which the valve body 7 protrudes, surrounding the valve body 7. This piston abutting body 8 has its base end inserted into a storage hole 9 formed annularly around the intake port 4 of the cylinder top 1a via a spring 10, and is pushed toward the piston by the spring 10. The distal end thereof is protruded into the expansion chamber 3 so as to be movable forward and backward from the storage hole 9 in such a manner that its protruding height is a certain height larger than that of the valve body 7.

Therefore, this piston contact body 8 is placed 1 with respect to the valve body 7.
I am trying to combine them like this:

That is, when the piston 2 descends and approaches the cylinder top 1a during the exhaust process of the expander, the piston contact body 8 is pushed by the piston end surface 2a and is forcibly retracted into the storage hole 9. On the other hand, when the piston 2 moves upward and away from the cylinder top 1a during the intake process, it follows the end surface 2a of the piston 2 by the action of the spring 10 and advances and extends into the expansion chamber 3. At this time, in order to prevent the piston abutting body 8 from being displaced beyond a certain level towards the piston side, a stepped portion 8a that comes into contact with the locking piece 7b of the valve body 7 is provided in the middle of its inner circumference. ing. In other words, this stepped portion 8a is formed when the piston abutting body 8 protrudes into the expansion chamber 3 by a certain amount or more.

It comes into contact with the lower surface of the peripheral edge of the latch piece 7b of the valve body 7 and is latched to the valve body 7, thereby preventing further displacement of the piston contact body 8 toward the piston side and its escape from the storage hole 9. It is supposed to play a role.

In FIG. 1, 11 indicates an intake pipe connected and communicated with the intake port 4, and 12 similarly indicates an exhaust port connected to the exhaust pipe 13 and opened on the side of the peripheral edge of the cylinder top 1a. ing.

Next, the operation of this intake valve will be explained with reference to FIG.

During the exhaust process of the expander, when the piston 2 approaches the cylinder top la from the bottom dead center side as shown in FIG. 1 (at this time, the exhaust bow 12 is opened), the piston 2 comes into contact with the piston abutting body 8 having a large protruding height, and gradually pushes the corresponding abutting body 8 to retract into the storage hole 9 (FIG. 3(a)). At this time, The valve body 7 maintains the valve closed state displaced toward the piston due to the internal pressure of the intake port filled with high-pressure working gas.
The piston 2 comes into contact with the locking piece 7b of the valve body 7 protruding into the expansion chamber 3, and together with the piston abutting body 8, pushes the valve body 7 away from the piston. Then, near the top dead center of the piston 2 at the end of the exhaust process, the valve body 7 is forcibly pushed and displaced by its end face 2a to the valve closed position on the opposite side of the piston, and at this time the intake port 4 is opened. (Fig. 3(b)).Next, when the piston 2 moves away from the cylinder top 1a during the intake process (at this time, the exhaust port 12 is switched to closed), the piston abutting body 8 While being urged by the spring 10 to advance and extend into the expansion chamber 3 to follow the piston end surface 2a, the valve body 7 remains stationary for a while and maintains the valve open state (Fig. 3). (C)), this means that once the valve body 7 is opened and high-pressure working gas flows into the expansion chamber 3, the pressure in the expansion chamber and the internal pressure of the intake port are balanced, and as long as no driving force is applied to the valve body, the valve This is because the body 7 becomes unable to move. When the piston abutting body 8 advances and extends beyond a certain level while maintaining this state, the corresponding abutting body 8 is latched to the latch piece 7b of the valve body 7 via the stepped portion 8a, and the piston abutting body 8 is latched onto the latching piece 7b of the valve body 7 through the stepped portion 8a. On the other hand, the spring force of the spring 10 that urges the piston abutting body 8 is borne on the valve body 7 that latches it, and as a result, the valve body 7 It is forcibly displaced toward the piston side by the spring force, and at the same time, the intake port 4 is closed (FIG. 3(d)).

Note that while the piston 2 is moving to the vicinity of its bottom dead center after this, the working gas is placed in an expansion process in which the working gas expands adiabatically in the l1al expansion chamber 3 with both the intake and exhaust ports 4.12 closed. It turns out. In this way, the valve body 7 that closes the intake port 4 automatically opens and closes at a predetermined timing every cycle of the expander.

If the intake port 4 is automatically opened and closed in this way, as is clear from the comparison with the one described in the above-mentioned Japanese Patent Application Laid-open No. 56-44556, the structural members required for the entire intake valve and the The mechanism can be made small and simple. That is, on the side of the cylinder top 1a,
It is only necessary to provide the valve body 7 in the intake port 4, the piston contact body 8 and the spring 10 in the storage hole 9, and the valve mechanism is characterized by a very simple internal structure.

Therefore, this kind of device has fewer parts, and each part can be easily processed and manufactured, making it inexpensive, so the cost required for the entire intake valve device is low, and its assembly is easy. I can do it. In addition, since the necessary springs can be compensated by temperature, there is no need to worry about spring selection or relative spring force adjustment, and the required loading space inside the cylinder top 1a is small, making it possible to use small expanders. It can be downsized to a size that can be applied to

Although one embodiment has been described above, the present invention is not necessarily limited to the case where it is implemented in the form of the illustrated embodiment as it is, and various other modifications can be considered. Fourth
The figure shows a modification of the one in Figure 1, in which the intake port 4 into which the valve body 7 is inserted and the storage hole 9 in which the piston abutting body 8 is housed are formed by a single common hole. ing. In addition to what is shown in this modified example, the overall shape of the valve body 7 (the valve body 7a and the locking piece 7b), the connection structure of the valve body 7, etc. Various modifications can be made as long as the port 4 is closed (on the contrary, the intake port 4 is opened when the piston is displaced toward the opposite side). In addition, there is room for modification in the shape of the piston abutting body 8 and the shape of the part that engages with the valve body 7, and the spring 10 used is not limited to the coil spring shown in the example shown, but may also be other than the spring 10, such as a countersunk spring. A spring, plate spring, etc. may also be used.

Next, another example of 1 kf March will be described.

In the above embodiment, as a means for returning the valve body 7 to the closed position at a predetermined timing during the intake expansion process of the expander,
In both cases, the piston abutting body 8 is directly latched by the valve body 7, so that the spring force of the spring lO that biases the piston abutting body 8 is applied to the valve body 7. 5
In other words, in this case, an appropriate number of valve bodies 14, 14 (valve body 14a and rod part 14b similar to those described above) are connected from the cylinder top 1a. ), and a piston contact body 15
．． 15 (in this case, it consists of a stepped rod having a small diameter part 15a and a large diameter part 15b, and 16 and 16 indicate a spring installed on the side opposite to the piston) are provided protrudingly, and each piston abuts. The body 15.15 is latched to each valve body 14.14 via an annular latching ring 17. That is, in this case, the former is directly fixed to the locking ring 17 with a screw 14d, etc., while the latter is inserted into the insertion hole 18 provided in the locking ring 17 with its small diameter portion 15a, and is inserted into the piston. When the contact body 15 advances and extends into the expansion chamber 3, the stepped portion 15c formed by the large diameter portion 15b comes into contact with the retaining ring 17 supported by the valve body 14, preventing further movement toward the piston side. Displacement is prevented. As is clear from this embodiment, the number and arrangement of the piston abutting body 15 and the valve body 14 at the cylinder top 1a are arbitrary, and the mechanism for hooking the piston abutting body 15 with the valve body 14 can also be done directly. It does not matter whether it is indirect or not.

Note that the exhaust valve attached to the expander together with the intake valve of the present invention is not necessarily limited to the form shown in the drawings, but may have any form as long as it can exhaust the expansion working gas from the expansion chamber at the required timing. I don't care.

[Effects of the Invention] As described above, the present invention improves the overall structure of the valve mechanism, such as using an internal mechanism and requiring only a single opening/closing screw without mechanically driving the valve body from a drive source on the normal temperature side. This makes it possible to provide something that is simpler, more compact, and has higher practical value.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of essential parts of an expander showing an embodiment of the present invention. FIG. 2 is a partially cutaway perspective view of the same embodiment. FIGS. 3(a), 3(b), 3(c), and 3(d) are sectional views of the main parts showing the operation of the same embodiment. FIG. 4 is a partial sectional view of a main part showing a modification of the one shown in FIG. FIG. 5 is a perspective view of main parts showing another embodiment of the present invention. FIG. 6 is a sectional view of essential parts of a conventional expander. l... Cylinder, 1a Fist... Cylinder top 2... Piston, 2a... Piston end face 3, Fist expansion chamber 4... Φ Intake port 5 Fist - Valve chamber, 6... Valve seat 7 .14... Valve body 7a, 14ae*a Valve body 7 b ・ ・ ・ tμmμ Minister 7c, 14c... Rod portion 7d, 14d・Fist・screw 8.15φ”・Piston contact body 8a, 15Cees stage Part 9φ...Storage hole 10.16 Fist...Spring 12・Φ・Exhaust port 17-Fist・Latching ring

Claims (1)

[Claims] In a reciprocating type expander in which a piston fitted in a cylinder is reciprocated to expand and contract an expansion chamber formed between the piston and the top of the opposing cylinder, an intake port is provided at the top of the cylinder, and the intake port is provided at the top of the cylinder. A valve body is irremovably inserted into the port, one end of which protrudes movably into the expansion chamber and which closes the intake port when it is displaced toward the piston. A piston abutting body that protrudes into the expansion chamber at a greater height than the valve body is provided so as to be movable forward and backward from the storage hole at the top of the cylinder, and the piston abutting body is urged toward the piston. When the abutting body advances and extends into the expansion chamber following the end face of the piston, the piston abutting body is latched by the valve body to prevent displacement of the piston abutting body beyond a certain level towards the piston side. An intake valve for an expander characterized by: