JPS61207864A - Output control device of stirling engine - Google Patents

Abstract

PURPOSE:To promote the improvement of operating efficiency, by opening and closing a pressure reducing valve, provided in the highest cycle line in a Stirling engine, and a pressure booster valve, provided in the lowest cycle line, by a control lever and opening a communicating valve, provided between suction and delivery sides of a working gas compressor, by detection of opening of the pressure reducing valve. CONSTITUTION:A Stirling engine connects the highest cycle line of each cylinder 1 with a pressure reducing valve 5 through check valves 2 while the lowest cycle line with a pressure booster valve 8 through check valves 6. Each valve 5, 8 connects with suction and delivery sides of a working gas compressor 3 by pipes 15, 16. Each pipe 15, 16 is connected by a bypass pipe 17 equipped with a solenoid operated valve 20. If the pressure reducing valve 5 operates so as to be opened by actuating a piston 10, receiving the pressure of gas in a pipe 7, or by controlling a lever 11 to manually handle its bottom end, the engine, closing a contact 19 to open the solenoid operated valve 20 and applying no load to the compressor 3 with no compression of the working gas, increases operating efficiency of the engine.

Description

Detailed Description of the Invention (Field of Application of the Invention) The present invention relates to an output control device for a Stirling engine, and more specifically, the present invention relates to an output control device for a Stirling engine. It is also used to reduce the burden on the suction and discharge valves.

(Prior Art and Its Problems) The output of a Stirling engine, which is an external combustion engine, is determined by the pressure within a working space filled with 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 4L 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 T and a line 16 via a check valve 6 . The line T and line 16 are connected through 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 via a rod. The accelerator lever 11 faces the valve rods 12 and 13 of the increase/decrease valves 8 and 5. The feedback piston cylinder 10 has a piston that moves in response to the minimum cycle pressure of 2 in 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 or decrease in output enters the stable range (predetermined value), the movable fulcrum 14
The pressure increase/decrease valves 8 and 5 close as the displacement decreases.

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, the special public
As disclosed in Japanese Patent No. 124, the pressure reducing valve 15 is omitted and the bypass line 17 has a valve 18t between both lines 15 and 16.
It is proposed to provide t-. This means, during steady operation of the Stirling engine, manually opens the valve 18, which serves as a speed reduction valve, to make the working gas pressures in both lines 15, 16 the same. As a result, during the steady operation, the working gas returns to the compressor 3 from the line 16, through the line 17 and through the line 15, and since the compressor 3 hardly performs compression work, the compressor 3 described above It is possible to eliminate obstacles to However, when entering steady operation, the valve 1 must be manually operated.
8 and then manually close the deceleration valve 1B during deceleration, which is cumbersome and undesirable in view of damage to the compressor 3 if this is neglected.

Therefore, Japanese Patent Publication No. 46-23535 teaches that two operating levers 11 are provided and one lever controls opening and closing of the bypass valve 18. However, this special public
Publication No. 23535 also requires manual operation of a lever to open and close the bypass valve 18, and the operating force of the lever is also large due to the pressure difference between the upstream and downstream sides of the bypass valve 18.

(Technical Problem of the Present Invention) A technical problem to be solved by the present invention is to eliminate the problems of the prior art described above.

(Technical means of the present invention and its effects) The present invention connects the upstream side of the pressure reducing valve and the downstream side of the pressure increasing valve by a bypass circuit having a solenoid valve, and the movement of the operating lever in the pressure reducing valve opening direction connects the upstream side of the pressure reducing valve and the downstream side of the pressure increasing valve. Basically, a method is adopted in which an operating sensor is provided and the opening and closing of the electromagnetic valve is controlled by the output from the sensor. This method is adopted because when the solenoid valve, which is open during normal operation, moves the control lever in the direction to reduce the output, the sensor closes the electric circuit connecting the power supply and the solenoid valve, and closes the solenoid valve. (The switch circuit is closed. In this state, the pressure reducing valve is open, so the compressor sucks working gas from the working space and the highest cycle pressure line, lowering the pressure in the working space. The deceleration is stable. When it enters the range, the movable fulcrum moves, the operating lever changes the pressure reducing valve from opening to closing, the sensor turns off, and the solenoid valve opens □.As a result, during steady operation, the pressure from the compressor is reduced. The working gas flows back to the compressor through the bypass circuit, and the amount of work done by the compressor becomes extremely small.

Since the movement of the operating lever is sent to the electromagnetic valve by an electrical signal, the operating force required to open and close the bypass circuit is extremely small.

(Embodiment) An embodiment of the present invention is shown in FIG. 1, and the same parts as those in the conventional example shown in FIG.

A sensor 19 such as a microswitch is arranged on the valve stem 13 of the pressure reducing valve 5. - 10,000, a line 15 downstream of the pressure reducing valve 5;
A line 16 on the upstream side of the pressure increase valve 8 is connected to a bypass line 17 having a solenoid valve 20. The ta valve 20 is electrically connected to the sensor 19. During steady operation of the Stirling engine, the solenoid valve 20 is in the open state and the compressor 3 is closed.
The working gas from the line 16 to the bypass line 17
The air returns to the compressor 3 through the line 15, and the suction and discharge amounts of the compressor 3 are the same, and the compressor 3 does no compression work.

When the operating lever 11 is displaced so as to push the valve stem 13 and open the pressure reducing valve 5, this movement of the operating lever 11 closes the sensor 19, energizes the solenoid valve 20, and causes the solenoid valve 20 to close.
Close. As a result, the bypass circuit is closed, and the working gas in the working space 1 is transferred to the highest cycle pressure line 4,
The compressed working gas is drawn into the compressor 3 through the pressure reducing valve 5 and the line 15, and is discharged into the line 16, reducing the pressure in the working space 1 and reducing the output of the Stirling engine. When the output reduction state becomes stable, the movable fulcrum 14 moves, the force pushing the valve stem 13 of the operating lever (-11) disappears, the pressure reducing valve 5 closes, and the sensor 19 also energizes the solenoid valve 20.

cut. Therefore, the solenoid valve 20 is opened, and the I-pass circuit is restored.

(Effects) In the present invention, the position of the valve incorporated in the bypass circuit can be selected independently of the position of the operating lever, so there is a high degree of freedom in design. Furthermore, since the bypass line is provided close to the suction and discharge valves of the compressor, the length of the bypass line can be shortened, the flow resistance of the working gas can be reduced, and the burden on the compressor can be further reduced.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention, and FIG. 2 is an explanatory diagram showing a conventional example. In the diagram = 1... working space, 3... compressor, 4... highest cycle pressure line, 5... pressure reducing valve, 7... lowest cycle pressure line, 8... pressure increasing valve, 11 ...Operation lever, 19...Sensor, 20...Solenoid valve.

Claims (1)

[Claims] A pressure reducing valve is provided in the highest cycle line that connects the working space to the working gas compressor and the working gas storage tank through a check valve, and further connects the working space to the working gas storage tank through the check valve. An output control device for a Stirling engine in which a pressure increaser valve is provided in a minimum cycle pressure line and the pressure increaser/reducer valve is controlled to open and close by an operating lever that swings about a movable fulcrum, the downstream side of the pressure reducer valve and the upstream side of the pressure increaser valve. A solenoid valve is disposed in a bypass circuit connecting the pressure reducing valve, a sensor is disposed that is activated when the operating lever is moved in the opening direction of the pressure reducing valve, and opening and closing of the solenoid valve is controlled by the output of the sensor. Stirling engine output control device.