JPS6357854A - Control device for operating gas pressure of stirling engine - Google Patents

Abstract

PURPOSE:To promote the sureness or the like of good running performance of a vehicle, by providing a three way type solenoid valve to be arranged between suction and delivery side lines of a compressor and controlling an unload valve to be opened and closed utilizing a line pressure in the delivery side so as to eliminate the necessity for forming the unload valve in a large size and for providing an auxiliary equipment. CONSTITUTION:A compressor 3 provides a three way type solenoid valve 19 to be arranged between suction and delivery side lines 15, 16. And the three way type solenoid valve 19, which connects a common port 19a with an unload valve 20, normally opened port 19b with the delivery side line 16 and a normally closed port 19c with the suction side line 15 respectively, places the above described port 19b to communicate with port 19c which a closing signal of a pressure reducing valve 5. While a control device provides the unload valve 20 to be arranged in a bypass line 17 connecting each of the above described lines 15, 16. In this way, the control device opens the unload valve 20 by a delivery side line pressure, when the pressure reducing valve 5 is closed, further utilizes the delivery side line pressure acting in the direction of closing the unload valve 20 with the opening of the pressure reducing valve 5.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a working gas pressure control device for a Stirling engine that includes an unload valve that utilizes working gas in a discharge line of a compressor for opening and closing.

BACKGROUND OF THE INVENTION The output of a Stirling engine, which is an external combustion engine, is determined by the pressure within a working space containing a working gas. For example, when increasing the output of a Stirling engine, the working gas pressure in the working space is increased. A typical conventional example of such a Stirling engine output control device is shown in FIG.
6-23534). The working space 1 of the Stirling engine is connected via a check valve 2 to a compressor 3 by a maximum cycle pressure line 4 and a line 15 . The line 4 and line 15 are connected through a pressure reducing valve 5. The working space 1 is also connected to the compressor 3 by a minimum cycle pressure line 7 and a line 16 via a check valve 6 .

The line 7 and line 16 are connected by a pressure increase valve 8. 9 indicates a high pressure tank.

The downstream side of the pressure increase valve 8 is connected to the feedback piston cylinder 1.
0, and the piston in the cylinder 10 is connected to the end of the accelerator lever 11, which serves as an operating lever, via a rod. The accelerator lever 11 is connected to the valve stem 12 of the increase/decrease valve 8.5.
, 13. Feedback piston cylinder I
The piston O moves in response to the pressure of the lowest cycle pressure line 7, and functions to displace the position of the fulcrum 14 of the accelerator lever 11.

When increasing the output of the Stirling engine, the accelerator lever 11 is pushed to the left to open the pressure increase valve 8, and high-pressure working gas is supplied from the compressor 3 or tank 9 to the working space 1. Further, when lowering the output of the Stirling engine, the accelerator lever 11 is pushed to the right to open the pressure reducing valve 5, and the pressure in the working space 1 is released to the compressor 3 side to reduce the pressure.

When the increase/decrease in output enters a stable range (predetermined value) during steady operation, the pressure increase/decrease valve 8.5 closes due to the displacement of the movable fulcrum 14.

By the way, during steady operation, the compressor 3 sucks working gas from line 15 and discharges high-pressure working gas to line 16, so the pressure difference between both lines 15 and 16 becomes large, that is,
A large pressure change occurs, the workload of the compressor 3 is large, and there are many obstacles to the compressor. Therefore, a bypass line 17 with an unload valve 18 between both lines 15°16 is used.
It is proposed that a This means is such that during steady operation of the Stirling engine ('$i valve 5 is closed), valve 1 is closed.
8 is opened manually to make the working gas pressures of both lines 15 and 16 the same. As a result, during the steady operation, the working gas flows from line 16 to line 17 and line 15.
The compressor 3 returns to the compressor 3 via the compressor 3, and since the compressor 3 hardly performs compression work, the above-mentioned trouble to the compressor 3 can be eliminated. However, it is cumbersome to manually open the valve 18 when steady operation begins and manually close the valve 18 during deceleration, and is not preferable in view of damage to the compressor 3 if this is neglected.

Therefore, it is conceivable to leave the pressure reducing valve 5 and arrange the solenoid valve 18 in the line 17, and close the solenoid valve 18 in response to the opening signal of the pressure reducing valve 5.

Problems to be Solved by the Invention The use of a solenoid valve that closes in response to the opening signal of the pressure reducing valve requires that the valve hole be enlarged in order to reduce the flow resistance of the working gas.
Since the valve member is exposed to high pressure gas, a large suction force is required. For this reason, the solenoid valve is large and requires a large amount of electric power, and when a Stirling engine is used in the output section of a vehicle, a large capacity battery or generator is required to be installed, which adversely affects the running performance of the vehicle.

Therefore, the present invention aims to solve the above-mentioned problems.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides the following steps to utilize the pressure of the discharge side line to control the opening and closing of the unload valve.
A three-way solenoid valve is placed between the suction and discharge lines, and when the pressure reducing valve is closed, the discharge side line pressure opens the unload valve, and when the pressure reducing valve opens, the discharge is directed in the direction that closes the unload valve. Use technical means to apply side line pressure.

Since the unload valve is opened and closed using the working discharge side line pressure, the unload valve can be made large and no auxiliary equipment is required.

Since the three-way solenoid valve only switches the flow direction of the discharge side line pressure, it may be small.

Embodiment One embodiment of the present invention is shown in FIG. 1, and the same parts as in the example of FIG. In the example shown in FIG.
0, 11, 12°13.14 are omitted.

A three-way solenoid valve 19 is arranged between the suction and discharge side lines 15 and 16 of the compressor 3, with its common port 19a connected to the unload valve 20, its normally open port 19b connected to the discharge side line 16, and its normally closed port connected to the discharge side line 16. 19c is connected to the suction side line 15, and when the pressure reducing valve 5 is closed, the port 19b and the port 19C are communicated.

Bypass line 17 connecting suction and discharge side lines 15 and 16
An unload valve 2o is placed at the. An example of the unload valve 20 is shown in FIG. The housing 21 of the unload valve 20 has a stepped bore, which is covered at the top and bottom with covers 22, 23. A piston 24 is disposed in the upper chamber, which is divided into a chamber 25 communicating with the common port 19a and a chamber 26 communicating with the suction side line 15. The lower chamber 27 communicates with the discharge side line 16, and this chamber 27 communicates with the suction side line 15 and the chamber 26? f
fl is formed by the valve member 29 that receives the biasing force of the spring 28. Valve member 29 is connected to piston 24 via stem 30.

When the pressure reducing valve 5 is closed, the piston 24 of the unload valve 20 is connected to the discharge line 1 through the common port 19a.
6, moves downward against the biasing force of the spring 28, and presses down the valve member 29. For this reason, both lines 1
5°16 is in communication state. On the other hand, when the pressure reducing valve 5 opens,
The normally closed port 19C is opened, the port 19b communicates with the port 19C, and the pressure in the discharge line 16 is transferred to the port 19C.
C and line 15 to the chamber 26, and the opposite pair of chambers 25, 26 are brought to the same pressure via the piston 24.

Therefore, due to the biasing force of the spring 28, the valve member 29
is closed. As a result, there is no bypass flow between both lines 15,16.

Effects In the present invention, since the high pressure gas on the cylinder side is used to open and close the unload valve, the opening and closing operation of the unload valve becomes reliable.

[Brief explanation of the drawing]

FIG. 1 is a detailed explanatory diagram of the present invention, FIG. 2 is a sectional view of an unload valve, and FIG. 3 is an explanatory diagram showing a conventional example. In the diagram: 1... Working space. 3... Compressor. 4... Maximum cycle pressure line. 5...Pressure reducing valve. 7...Minimum cycle pressure line. 8... Pressure increase valve. 19...Three-way solenoid valve. 20...Unload valve.

Claims (1)

[Claims] A pressure increasing valve provided on the lowest cycle pressure line connected to the working space via a one-way valve, a pressure reducing valve provided on the highest cycle pressure line connected via the one-way valve during the operation, and opening/closing of the pressure increasing/reducing valve. a compressor having a suction and discharge side line connected to the both cycle pressure lines via a one-way valve, an unload valve disposed in a circuit that short-circuits the suction and discharge side lines of the compressor, and a constant A working gas pressure control device for a Stirling engine having a three-way solenoid valve having an open port connected to the discharge side line, a normally closed port connected to the highest cycle pressure line, and a common port connected to the working chamber of an unload valve.