JPS61223250A - Control valve for multicylinder stirring engine - Google Patents

Abstract

PURPOSE:To reduce the leak of gas and heat to the min. by constituting the captioned control valve so that a bypass passage is opened when the ratio between the max. pressure and the min. pressure in each operation space of a multicylinder Stirling engine exceeds a prescribed value and the working gas in the max. pressure pipe is discharged to the min. pressure pipe. CONSTITUTION:The captioned control valve 30 is installed between a conduit 23 connected between the compression space of each cylinder of a multicylinder Stirling engine and an auxiliary conduit 21 connected to a feeding conduit communicating to the compression space, and a valve 50 is accommodated in shiftable ways into a housing 40. Said valve 50 is constituted of a stepped piston, and the high and low pressure cylinder chambers 43 and 44 can be partitioned by the front and rear edge surfaces 51 and 52 and the inner surface of the housing 40. The ratio R1 between the areas S1 and S2 of the edge surfaces 51 and 52 is set a little smaller than the ratio R2 in ordinary case between the min. pressure P1 and the max. pressure P2 in the operation space of each cylinder. Further, a bypass passage 54 is formed onto the side peripheral surface of the valve 50, and the bypass ports 41 and 42 are allowed to communicate when the valve 50 is shifted.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a control valve that controls the pressure in each working space of a Stirling engine so as to maintain equilibrium. It is used in multi-cylinder double-acting Stirling engines, etc., which require balance of maximum cycle pressure.

(Prior Art) A conventional device of this type is disclosed in Japanese Patent Application Laid-Open No. 57-83647. In this conventional pressure balancing device, the cycle maximum pressure of each working space is guided to each cylinder 60, as shown in FIG. When the maximum pressure in at least one working space changes and the equilibrium is disrupted, the sliding member 62 slides due to the biasing force of the spring 61, and releases high pressure gas to the low pressure circuit side through the release hole 63, thereby reducing the pressure. Maintaining equilibrium.

(Problems to be Solved by the Invention) In the conventional device described above, the number of pressure adjustment mechanisms such as cylinders, springs, and sliding members is required to be the same as the number of working spaces of the Stirling engine. The problem was that it became complicated. In addition, in the above device, even if there is a small cycle maximum pressure difference between cylinders that does not interfere with engine operation, if it occurs, the working space is always the lowest among the cycle maximum pressures of all working spaces. control to match the pressure. Therefore, a large amount of gas and heat leaked through the discharge hole, resulting in a problem that the engine performance deteriorated.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a pressure equalization device that has a simple, inexpensive structure, automatically adjusts, and minimizes leakage of gas and heat. purpose.

[Structure of the Invention] (Means for Solving the Problems) The 1lJIIIl valve of the present invention is connected to each working space of a multi-cylinder Stirling engine through a check valve from which working gas exits, and all A high-pressure cylinder chamber connected to the highest pressure pipe where the highest pressure in the space becomes the pipe internal pressure, and a high-pressure cylinder chamber connected to each working space via a check valve that allows working gas to enter the working space, A housing having a low pressure cylinder chamber connected to a minimum pressure pipe whose minimum pressure is the internal pressure of the pipe, and a bypass passage communicating with the highest pressure pipe and the minimum pressure pipe; It has a piston part and a low pressure piston part that slides in the low pressure cylinder chamber, and the housing is moved in forward and reverse directions by the relative pressure received by the high pressure piston part and the low pressure piston part, and the entire body received by the high pressure piston part is moved in the forward and reverse directions. It is characterized by comprising a valve that opens the bypass passage when the pushing force is greater than the total pushing force received by the low-pressure piston portion, and closes the bypass passage when the opposite occurs.

The control valve of the present invention is comprised of a housing and a valve disposed within the housing.

The housing is provided with a high pressure cylinder chamber and a low pressure cylinder chamber. A maximum pressure pipe in which the maximum pressure in each working space of the multi-cylinder Stirling engine is the internal pressure is connected to this high pressure cylinder chamber. This highest pressure pipe communicates with each working space via a check valve that opens only in the direction in which working gas exits from each working space. Therefore, the pressure in the highest pressure pipe becomes the highest pressure in each working space. Note that there is no particular restriction on the number of working spaces that communicate with the highest pressure pipe, and it is possible to make a single highest pressure pipe communicate with a large number of working spaces.

A minimum pressure pipe in which the minimum pressure in each working space of the multi-cylinder Stirling engine is the internal pressure is connected to the low pressure cylinder chamber. This minimum pressure pipe opens only in the direction in which the working gas enters each working space (communicates with each working space via a check valve).The minimum pressure pipe can also communicate with a working gas reservoir.

The housing is provided with a bypass passage that communicates the highest pressure pipe and the lowest pressure pipe. This bypass passage makes it possible to release excess pressure when the pressure balance of the engine is disrupted.

The valve includes a high-pressure piston portion that slides in the high-pressure cylinder chamber,
and a low-pressure piston portion that slides in the low-pressure cylinder chamber. Each piston part may be a separate body,
It can also be formed integrally. The high pressure piston part is biased in one direction by the highest pressure led from the highest pressure pipe,
The low pressure piston section is biased in a direction opposite to the biasing force of the high pressure piston section by the minimum pressure introduced from the minimum pressure pipe. The biasing forces from both directions move the valve in the forward and reverse directions, making it possible to open and close the bypass passage. However, if this continues, the urging force applied to the high-pressure piston portion will exceed the urging force applied to the low-pressure piston portion, and the valve will move in only one direction. Therefore, it is necessary to increase the urging force applied to the low-pressure piston portion by some means. As this means, for example, the biasing force of a spring can be used. In addition, by making the area of the part of the high-pressure piston part that receives the maximum pressure biasing force smaller than the area of the part of the low-pressure piston part that receives the minimum pressure biasing force, the total stress in the high-pressure piston part and that of the low-pressure piston part are reduced. It is also possible to balance the total stress. According to this means, the ratio of the maximum pressure and the minimum pressure of the engine known in advance is set as the area ratio of each piston part, and the bypass passage can be kept in a closed state unless the pressure ratio is exceeded. can. Therefore, leakage of gas and heat through the bypass passage can be minimized, and it is possible to maintain pressure balance in most engines simply by changing the area ratio of the piston portion.

When employing the above means for changing the area ratio of each piston portion, it is desirable that the valve be an integrally formed two-stage piston with a stepped cross section. It is also possible to provide a groove or the like on the valve surface so that when the pressure ratio exceeds a predetermined value and the valve moves, the bypass passage of the housing coincides with the groove and opens the bypass passage. In this case, it is desirable that a constant pressure be maintained between the shoulder of the valve and the housing so that the movement of the valve is not hindered by negative pressure. For example, it may be released to the atmosphere, but if there is a leak of working gas, it is desirable to connect it to a working gas storage chamber or the like that is adjusted so that the pressure will not change even if the working gas moves.

(Operation) In the control valve of the present invention, the maximum and minimum pressures in each working space of the multi-cylinder Stirling engine are applied to the high-pressure piston portion and the low-pressure piston portion of the valve. When the ratio of the highest pressure to the lowest pressure exceeds a predetermined value, the valve moves within the housing to open the bypass passage and allow the working gas in the highest pressure tube to escape into the lowest pressure tube. When the ratio of the maximum pressure to the minimum pressure becomes less than or equal to a predetermined value, the valve moves to its original position and the bypass passage becomes closed.

(Example) This will be explained in detail below using examples.

FIG. 1 shows a system diagram of a multi-cylinder Stirling engine using a control valve according to an embodiment of the present invention.

Pistons 2a to 2d are connected within the sills and ferns 1a to 1d of the Stirling engine by a crank (not shown) via rods 3a to 3d with a phase difference. The space inside the cylinder is filled with seal members 48 to 4 provided on the piston.
The rain space 5a is divided into expansion spaces 1115a to 5d having a high temperature and compression spaces 6a to 6d having a low temperature.
5d, 5a to 6d are connected via heaters 7a to 7d, heat storage devices 8a to 8d, and coolers 98 to 9d, and each constitutes an operating space. This working space is filled with working gas consisting of helium, and the burner 2
28 to 22d are heated by heaters 7a to 7d. The main pipes 10a to 10d are connected to the compression chambers 116a to 6d, and the first check valves 11a to 11d, which open only in the direction of the compression spaces 68 to 6d, the supply conduit 14 and the supply valve 15 are used for storage! 116. And supply guidance! !
The pressure within 14 is adjusted to be the minimum pressure in each working space. Similarly, the main pipes 10a to 10d open only in the opposite direction to those of the main pipes 11i6a to 6d during compression. Pressure reducing valve 18 and compressor 1
9 to the reservoir 16.

Even more initiative! ! 10a to 10d are third check valves 13a to 13d that open only in the opposite direction to the compression spaces 68 to 6d, and control valves 3 via conduits 20a to 20d and conduits 1!23.
Connected to 0. Conduits 20a to 20d are all conduits 2
It is connected to 3. Further, the control valve 30 is connected to the auxiliary conduit 2.
1 is also connected to the supply conductor 114.

As shown in FIG. 2, the control valve 30 includes a housing 40,
The valve 50 is configured to move in the axial direction within the housing 40.

A conduit 23 is connected to one end of the housing 40, and an auxiliary conduit 21 is connected to the other end, each of which communicates with the internal space. Further, a maximum pressure bypass port 41 and a minimum pressure bypass port 42 are provided on the side of the housing 40 and communicate with the internal space, and a conduit 23 and an auxiliary conduit 2 are provided, respectively.
It communicates with 1.

- In the valve 50, the area S1 of one end surface 51 is the area S2 of the other end surface 52.
In the internal space of the housing 40, which is composed of smaller stepped pistons and has an inner diameter that is approximately the same as the diameter of each end surface, airtight pistons are inserted in both forward and reverse axial directions through ring-shaped gas seals 53a to 53d. Arranged so that it can be moved.

One end 51 and the inner surface of the housing 40 form a high-pressure cylinder chamber 43, and the other end 52 and the inner surface of the housing 40 form a low-pressure cylinder chamber 44. Note that the ratio R1 (R1
=S1/82) is slightly smaller than the normal ratio R2 (R2-P1/P2) between the minimum pressure P1 and the maximum pressure P2 in each working space.

A bypass passage 54 is provided on the side peripheral surface of the valve 50.
0 moves and the other end surface 52 comes into contact with the inner wall of the housing 40, the bypass port 4 passes through the bypass passage 54.
1 and the bypass port 42 are configured to communicate with each other.

Also, in the cavity @ 45 formed by the shoulder 55 of the valve 50 and the housing 40, there is a passage 5 leading to a working gas storage chamber (not shown).
6 is open, the space 45 is always maintained at atmospheric pressure, and the valve 50 is easily movable.

The operation of the control valve 30 configured as described above will be explained below. Let us assume that the sealing performance of the sealing member 4a of the piston 2a deteriorates.

When the working gas leaks from the expansion space 1115a to the compression space 6a, the cycle pressure of the working space formed by the compression space 5a, cooler 9a, heat storage device 8a1, heater 7a, and expansion space 5b becomes higher than the cycle pressure of the other three working spaces. It gets loud. Then, the pressure is formed in the high pressure cylinder chamber 43 through the third check valve 13a, the conduit 20a and the conduit 23. At normal times, the entire pushing force applied to the other end surface 52 is
1, the valve 50 is stopped at the position where the shoulder 55 abuts the inner surface of the housing 40. At this time, the bypass ports 41, 42 are not communicating with each other. Then, when the pressure in the high-pressure cylinder chamber 43 rises and the ratio R of the pressure in the low-pressure cylinder chamber and the pressure in the high-pressure cylinder chamber exceeds the ratio R1, the valve 50 begins to move, and the other end 52 comes into contact with the inner surface of the housing 40. It will be in a position where they are in contact with each other. At this position, the bypass boat 41 and the bypass boat 42 are connected to the bypass passage 5.
4, the high pressure working gas in conduit 20a escapes via auxiliary conduit 21 to supply conduit 14. Further, since the pressure in the working space associated with the expansion space 5a decreases due to leakage of the working gas, the supply 1
Working gas is supplied from 11114. and pressure ratio R
When becomes smaller than R1, the valve 50 returns to its original position and the bypass ports 41, 42 are closed. Therefore, the cycle maximum pressure and the cycle minimum pressure of each working space are kept substantially equal, the output of each working space can be made substantially equal, and the generation of vibration and noise can be prevented.

[Effects of the Invention] As another means for achieving the same objective, it is conceivable to provide a needle valve between the highest pressure circuit and the lowest detour and manually operate it. However, this method requires complicated operations such as the need to monitor the pressure state. It is also conceivable to use an electromagnetic valve instead of a needle valve, and to automatically open and close the valve by outputting a signal through a pressure transducer for the maximum pressure and the minimum pressure. However, this requires a pressure transducer, a dynamic sistometer, a controller, etc., and is expensive.

According to the control valve of the present invention, pressure balance can be automatically maintained even in a multi-cylinder Stirling engine by using only one control valve. Therefore, the number of parts is reduced, the device is simplified, and space is saved. Furthermore, when a pressure abnormality occurs, the chisel action debris is released, so gas and heat leakage can be minimized. Therefore, the cycle pressures in each working space are balanced with minimal loss, and the output of each working space can be made approximately equal, which has a great effect in preventing the generation of vibration and noise.

[Brief explanation of the drawing]

1 and 2 relate to a control valve according to an embodiment of the present invention, FIG. 1 is a system diagram of a multi-cylinder Stirling engine using the control valve, and FIG. 2 is a sectional view of the control valve. FIG. 3 is a schematic diagram of a conventional pressure equalization device. 18-1d...Cylinder 2a-2d...Piston 30...Control valve 40...Housing 41
．． 42...Bypass boat 43...High pressure cylinder chamber 44...Low pressure cylinder chamber 50...Valves 53a to 53d...Gas seal 54...Bypass passage

Claims (4)

[Claims] (1) A high pressure pipe connected to each working space of the multi-cylinder Stirling engine through which working gas comes out through a check valve, and connected to the highest pressure pipe where the highest pressure in all the working spaces becomes the pipe pressure. A low-pressure cylinder chamber connected to each working space via a cylinder chamber and a check valve that allows working gas to enter the working space, and connected to a minimum pressure pipe such that the minimum pressure in all the working spaces becomes the pipe internal pressure. a housing having a bypass passage communicating with the highest pressure pipe and the lowest pressure pipe; a high pressure piston portion that slides within the high pressure cylinder chamber; and a low pressure piston portion that slides within the low pressure cylinder chamber; The high-pressure piston section and the low-pressure piston section move in the forward and reverse directions within the housing due to the relative pressures that they receive, and the movement occurs when the total pushing force that the high-pressure piston section receives is greater than the total pushing force that the low-pressure piston section receives. A control valve for a multi-cylinder Stirling engine, comprising a valve that opens the bypass passage and closes the bypass passage in the opposite case. (2) The high-pressure piston section and the low-pressure piston section slide on the same axis, and the ratio of the area of the end surface to which the pushing force of the high-pressure piston section is applied and the area of the end surface to which the pushing force of the low-pressure piston section is applied is the same under normal conditions. The control valve for a multi-cylinder Stirling engine according to claim 1, wherein the control valve is configured to be slightly smaller than the ratio between the minimum pressure and the maximum pressure of each working space. (3) The control valve for a multi-cylinder Stirling engine according to claim 1, wherein the valve is a stepped piston with a stepped cross section in which a low-pressure piston portion and a high-pressure piston portion are integrally formed. (4) The control valve for a multi-cylinder Stirling engine according to claim 3, wherein the space formed by the shoulder of the valve having a stepped cross section and the inner surface of the housing communicates with a working gas storage chamber.