JP5682163B2 - Supercharging device with supercharging assistance and discharge control valve - Google Patents

Description

  The present invention relates to a supercharging device with supercharging assistance that uses a pressure accumulating tank for supercharging assistance to alleviate turbo lag in a turbocharged engine, and is equipped with supercharging assistance that can adjust the amount of air introduced into a combustion chamber. The present invention relates to a device and a discharge control valve used therefor.

  In an engine using a turbocharger (supercharger), more air can be sucked into the combustion chamber by the action of the turbocharger, so that it is possible to improve torque performance and reduce pollutants in the exhaust gas.

  A turbocharger has an impeller attached to each end of a single shaft. The turbocharger rotates the turbine by flowing exhaust through one impeller (turbine), and the other impeller (compressor) that rotates thereby causes air to flow. Compress. As described above, the turbocharger is a system that compresses air by work extracted from exhaust gas. Engines using a turbocharger increase the amount of air introduced into the combustion chamber by repeating the cycle of supercharging the air compressed by the turbocharger into the combustion chamber and further rotating the turbine with exhaust from the engine I will let you.

JP-A-8-260991

  Turbochargers have the problem of turbo lag. The turbo lag is a time difference from when the turbocharger is requested for the amount of air until the amount of air can be taken into the combustion chamber. Turbo lag is a phenomenon that always occurs on the principle of turbocharger. In particular, turbo lag is likely to occur during transient operation where the engine condition has changed.

  When the turbo lag occurs, the output torque performance and the exhaust performance deteriorate because the amount of air sucked into the combustion chamber is small with respect to the fuel amount determined from the changing engine speed and accelerator opening.

  As a supercharging assist device that improves the deterioration of output torque performance and exhaust performance due to turbo lag, air that has been compressed in advance using a supercharger or compressor for accumulating pressure is stored in the accumulator tank, and air from the accumulator tank is taken into the intake path during turbo lag There is something that supplements the amount of air by releasing it.

  A conventional supercharging device with supercharging assistance is shown in FIG.

  The supercharging device with supercharging assistance shown in FIG. 8 is connected to a turbine 802 that is rotated by exhaust gas from an engine 801 and a compressor 805 that compresses air obtained from the atmosphere through an intake pipe 803 and sends the compressed air to an intake manifold 804. A low pressure turbocharger 806, a backflow prevention valve 807 that shuts off the intake pipe 803 upstream of the low pressure turbocharger 806 at the time of supercharging assistance, a pressure accumulation tank 808 in which compressed air for supercharging assistance is stored, and supercharging assistance Sometimes, one end is connected to the pressure-accumulation release valve 809 for releasing air from the pressure-accumulation tank 808, the outlet of the pressure-accumulation release valve 809, and the other end is connected to the intake pipe 803 between the low-pressure turbocharger 806 and the backflow prevention valve 807. A discharge pipe 810.

  More specifically, an exhaust pipe 812 that guides exhaust gas from the exhaust manifold 811 to the atmosphere is switched between an exhaust passage through the turbine 814 of the high-pressure turbocharger 813 and a direct exhaust passage from the exhaust manifold 811 to the turbine 802. An exhaust gas switching valve 815 for flowing exhaust gas is provided. A waste gate valve 817 that diverts the exhaust gas to the exhaust switching valve 815 is provided in the high-pressure turbo exhaust pipe 816 that guides the exhaust gas from the exhaust manifold 811 to the turbine 814.

  An intake pipe 803 downstream of the compressor 805 of the low-pressure turbocharger 806 is connected to an inlet of the compressor 818 of the high-pressure turbocharger 813 and one inlet of an intake air switching valve 819 that switches the intake air flow path. A high-pressure turbo intake pipe 820 from the outlet of the compressor 818 is connected to the other inlet of the intake air switching valve 819. An intake pipe 803 downstream of the intake air switching valve 819 is connected to an intake manifold 804 via an intercooler 821. An intake throttle 822 is provided downstream of the intercooler 821. An air cleaner 823 is provided upstream of the backflow prevention valve 807 in the intake pipe 803. An air amount sensor 824 is provided immediately upstream of the inlet of the compressor 805.

  An oxidation catalyst (Diesel Oxidation Catalyst; DOC) 825 and a diesel particulate filter (Diesel Particulate Filter or Defuser; DPF or DPD) 826 are provided downstream from the outlet of the turbine 802 of the low-pressure turbocharger 806.

  A pressure accumulating compressor 827 for taking in compressed air is connected to the pressure accumulating tank 808.

  As shown in FIG. 9, in normal operation, that is, because the engine rotation speed and output torque do not change significantly and the accelerator opening is a steady operation, the turbo lag hardly occurs and supercharging assistance is not performed. At this time, the backflow prevention valve 807 is opened so that air from the atmosphere can be sucked into the compressor 805 of the low-pressure turbocharger 806. The pressure accumulation release valve 809 is closed. By such valve control, compressed air is not discharged to the discharge pipe 810, but only air from the atmosphere is introduced into the low-pressure turbocharger 806 and supercharged to the engine 801. At this time, the pressure accumulating compressor 827 is operated to store the compressed air in the pressure accumulating tank 808.

  As shown in FIG. 10, at the time of supercharging assistance, that is, when the engine rotation speed and the output torque change greatly, and in a transient operation where the accelerator opening greatly increases at a stretch, turbo lag is likely to occur, so supercharging assistance is performed. At this time, the backflow prevention valve 807 is closed so that the compressed air does not flow back to the air cleaner 823 upstream of the intake pipe 803, and the pressure accumulation release valve 809 is opened. By such valve control, the compressed air in the pressure accumulation tank 808 is supplied to the compressor 805.

  Here, the structure of the pressure accumulation release valve 809 will be described. As shown in FIG. 11, the pressure accumulation release valve 809 includes a discharge pipe 1101 for connecting a compressed air supply source and a compressed air consumption destination, Between the cylinder 1102 inclined and fixed to the pipe 1101, the first fixed partition 1103 and the second fixed partition 1104 fixed in the cylinder 1102 and facing each other, and between the first fixed partition 1103 and the second fixed partition 1104. A hydraulically movable partition wall 1105 that is disposed and can be hydraulically moved in the cylinder 1102, and an oil filler port 1106 that is opened in the cylinder 1102 to introduce a working fluid between the first fixed partition wall 1103 and the hydraulically movable partition wall 1105; The hydraulic movable partition 1105 is disposed between the hydraulic movable partition 1105 and the second fixed partition 1104 so that the hydraulic movable partition 1105 is directed toward the first fixed partition 1103. The spring 1107 to be energized and the discharge pipe 1101 outside the one end side of the cylinder 1102 pass through the first fixed partition wall 1103 and the second fixed partition wall 1104 to the other end side of the cylinder 1102, and the hydraulic movable partition wall 1105. The valve body driving rod 1108 integrated with the valve body driving rod 1108 is fixed to one end of the valve body driving rod 1108 and accommodated in the discharge pipe 1101 so as to be movable from the opened state to the closed state. And a valve body 1109.

  A hydraulic pipe 1110 is connected to the oil supply port 1106, and working fluid is supplied to the hydraulic pipe 1110 via an electromagnetic valve 1111.

  As shown in FIG. 12A, at the time of supercharging assistance, the electromagnetic valve 1111 is activated, and the working fluid is introduced between the first fixed partition 1103 and the hydraulic movable partition 1105 from the oil filler port 1106. The hydraulic movable partition 1105 moves to the other end side (upper right direction in the figure) of the cylinder 1102. Accordingly, the valve body driving rod 1108 moves to the other end side of the cylinder 1102 and the valve body 1109 opens the discharge pipe 1101, so that the compressed air is discharged through the discharge pipe 1101.

  As shown in FIG. 12B, when the supercharging assistance is completed and the normal operation returns, the operation of the solenoid valve 1111 is stopped, and the hydraulic movable partition wall 1105 is moved to one end side of the cylinder 1102 by the force of the spring 1107 (lower left in the drawing). The working fluid is discharged from the oil filler port 1106. The valve body driving rod 1108 moves to one end side of the cylinder 1102, and the valve body 1109 closes the discharge pipe 1101.

  Here, since the pressure of the working fluid is always constant, the pressure accumulation release valve 809 can only control whether it is fully open or fully closed.

  For this reason, in the conventional supercharging device with supercharging assistance, when the amount of compressed air stored in the accumulator tank 808 in advance is larger than the required amount of air according to the state of the engine, the engine 801 releases the compressed air with supercharging assistance. The amount of air introduced into the combustion chamber becomes greater than the required amount. For this reason, an overshoot occurs in which the engine rotation speed becomes larger than the target. That is, as shown in FIG. 13 (a), after the supercharging assistance is started by closing the backflow prevention valve 807 and opening the pressure accumulating release valve 809, the amount of air introduced into the combustion chamber of the engine 801 is no supercharging assistance. Since the output torque increases faster than the case, the output torque rises quickly, but the air amount becomes excessive and the output torque greatly exceeds the target. At this time, as shown in FIG. 13B, an overshoot occurs in which the engine rotation speed becomes larger than the target.

  Further, depending on the engine state, the compressed air released from the pressure accumulating tank 808 is introduced into the combustion chamber, so that the pressure in the combustion chamber may become equal to or higher than the limit value defined for the engine 801. As shown in FIG. 13 (c), in a state where the air amount after the start of supercharging assistance is exceeded, the maximum value of the combustion chamber pressure is much larger than that without supercharging assistance.

  In addition, the shortening of the ignition delay period accompanying the increase in the amount of air introduced into the combustion chamber adversely affects the exhaust gas performance.

  Accordingly, an object of the present invention is to solve the above-described problems and provide a supercharging device with supercharging assistance and a discharge regulating valve capable of adjusting the amount of air introduced into the combustion chamber.

To achieve the above object, the present invention provides a turbocharger in which a turbine rotated by engine exhaust and a compressor that compresses air obtained from the atmosphere through an intake pipe and sends the compressed air to an intake manifold, and supercharging assistance A backflow prevention valve that sometimes shuts off the intake pipe upstream of the turbocharger, a pressure accumulation tank in which compressed air for supercharging assistance is stored, an intake pipe from the turbocharger to the backflow prevention valve, and the pressure accumulation tank It is provided between them and is driven to open and close by hydraulic pressure. When closed, the compressed air from the pressure accumulating tank is not released, and when opened, the compressed air from the pressure accumulating tank is released to the compressor, and the intake air is released when hydraulic pressure is released. When the internal pressure of the intake manifold is increased by the air pressure from the manifold, the release adjustment valve decreases as the opening degree decreases. When a supercharger assisting device equipped with a pipe drive air directing air to the discharge control valve from the intake manifold and connecting the discharge control valve and the intake manifold.

The present invention also includes a pipe, a cylinder fixed to the pipe, a first fixed partition and a second fixed partition fixed in the cylinder and facing each other, the first fixed partition and the second fixed partition. A hydraulic movable partition wall disposed between the hydraulic movable partition wall and hydraulically movable in the cylinder, and an oil filler port opened in the cylinder for introducing a working fluid between the first fixed partition wall and the hydraulic movable partition wall; A spring disposed between the hydraulic movable partition and the second fixed partition and biasing the hydraulic movable partition in the direction of the first fixed partition; A valve body driving rod integrated with the hydraulic movable partition wall and fixed to one end of the valve body driving rod, passing through one fixed partition wall and the second fixed partition wall and coming out of the other end side of the cylinder. And the piping A valve body state is movably accommodated in the inside of the pipe to which is closed from the state released, an air chamber adjacent the leading Symbol cylinder, fixed to the other end of said valve body drive rod, movably pneumatically said air chamber housed pneumatic moving partition, introducing air the pneumatic moving partition within the air chamber so as to urge the said cylinder direction, and an air inlet opened in the air chamber, When the internal pressure in the air chamber increases when the air chamber is opened, the release control valve decreases in opening.

  The present invention exhibits the following excellent effects.

  (1) The amount of air introduced into the combustion chamber can be adjusted.

It is a block diagram of the supercharging device with supercharging assistance which shows one Embodiment of this invention. It is a figure which shows the valve control at the normal time of the supercharging device with supercharging assistance of FIG. It is a figure which shows valve control at the time of supercharging assistance of the supercharging device with supercharging assistance of FIG. It is a figure which shows valve control at the time of supercharging assistance adjustment of the supercharging device with supercharging assistance of FIG. It is an internal detail drawing of the discharge control valve which shows one Embodiment of this invention. It is a figure which shows the internal motion in valve control of the discharge | release control valve of this invention, (a) is normal time, (b) is at the time of supercharging assistance, (c) is at the time of supercharging assistance adjustment, (d) is excessive. Indicates the normal time after subsidy. It is a figure which shows the characteristic of the supercharging apparatus with a supercharging assistance of this invention, (a) is a change waveform figure of the output torque when not performing supercharging assistance, (b) When performing supercharging assistance FIG. 6 is a waveform diagram showing a change in the maximum value of the combustion chamber pressure when not performed. It is a block diagram of the conventional supercharging device with supercharging assistance. It is a figure which shows the valve control at the normal time of the supercharging device with supercharging assistance of FIG. It is a figure which shows valve control at the time of supercharging assistance of the supercharging device with supercharging assistance of FIG. It is an internal detail drawing of the conventional pressure accumulation release valve. It is a figure which shows the internal motion in the valve control of the conventional pressure accumulation release valve, (a) is at the time of supercharging assistance, (b) shows the normal time after supercharging assistance. It is a figure which shows the characteristic of the conventional supercharging device with a supercharging assistance, (a) is a change waveform figure of the output torque when not performing supercharging assistance, (b), When performing supercharging assistance FIG. 5C is a waveform diagram of change in the maximum value of the combustion chamber pressure when the supercharging assistance is performed and when it is not performed.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1, the supercharging device with supercharging assistance according to the present invention compresses air obtained from an atmosphere through an intake pipe 803 and a turbine 802 rotated by exhaust of an engine 801 into an intake manifold 804. A turbocharger (hereinafter referred to as a low-pressure turbocharger) 806 connected to a compressor 805 to be sent, a backflow prevention valve 807 that shuts off the intake pipe 803 upstream of the low-pressure turbocharger 806 during supercharging assistance, and compressed air for supercharging assistance Is stored between the pressure accumulation tank 808, the intake pipe 803 from the low pressure turbocharger 806 to the backflow prevention valve 807, and the pressure accumulation tank 808. The pressure accumulation tank 808 is driven to be closed and opened by hydraulic pressure. Without releasing, when opened, the compressed air in the pressure accumulating tank 808 is released to the compressor 805, and The release control valve 101, which is driven by the air pressure from the intake manifold 804 when the hydraulic pressure is released and the internal pressure of the intake manifold 804 becomes high, is connected to the intake manifold 804 by connecting the intake manifold 804 and the release control valve 101 to each other. And a drive air pipe 102 that guides air from the discharge control valve 101 to the discharge control valve 101.

  As described above, the supercharging device with supercharging assistance of the present invention is provided with the discharge regulating valve 101 in place of the pressure accumulating release valve 809 with respect to the conventional supercharging device with supercharging assistance of FIG. Is adjusted in accordance with the internal pressure of the intake manifold 804. The relationship between the internal pressure of the intake manifold 804 and the opening degree of the release control valve 101 is set in advance by experiments.

  The operation of the supercharging device with supercharging assistance according to the present invention will be described below.

  As shown in FIG. 2, during normal operation, that is, when there is no supercharging assistance because of a steady operation in which turbo lag is unlikely to occur, the backflow prevention valve 807 is opened and air from the atmosphere is compressed by the compressor 805 of the low-pressure turbocharger 806. Make sure you can inhale. The discharge control valve 101 is closed. By such valve control, compressed air is not released, but only air from the atmosphere is introduced into the low-pressure turbocharger 806 and supercharged to the engine 801. At this time, the pressure accumulating compressor 827 is operated to store the compressed air in the pressure accumulating tank 808.

  As shown in FIG. 3, at the time of supercharging assistance (before supercharging assistance adjustment starts), that is, when the supercharging assistance is being performed because of the transient operation in which turbo lag is likely to occur, the backflow prevention valve 807 is closed and the intake air is inhaled. The compressed air is prevented from flowing back into the air cleaner 823 upstream of the pipe 803, and the discharge control valve 101 is opened. By such valve control, the compressed air in the pressure accumulation tank 808 is supplied to the compressor 805.

  As shown in FIG. 4, at the time of supercharging assistance adjustment, that is, when the internal pressure of the intake manifold 804 increases due to the effect of supercharging assistance, the opening degree of the discharge regulating valve 101 becomes small. As a result, the amount of compressed air introduced into the compressor 805 of the low-pressure turbocharger 806 is reduced, and the amount of air introduced into the combustion chamber of the engine 801 does not exceed.

  Next, the detailed structure of the discharge control valve 101 will be described with reference to FIG.

  The discharge control valve 101 is a discharge for connecting a compressed air supply source (not shown) (for example, a pressure accumulation tank 808 in FIG. 1) and a compressed air consumption destination (for example, the compressor 805 of the low-pressure turbocharger 806 in FIG. 1). A pipe 111, a cylinder 112 fixed to the discharge pipe 111 at an inclination, a first fixed partition 113 and a second fixed partition 114 fixed in the cylinder 112 and facing each other, a first fixed partition 113 and a second fixed A hydraulic movable partition 115 disposed between the partition 114 and movable in the cylinder 112 by hydraulic pressure, and a cylinder 112 is opened to introduce a working fluid between the first fixed partition 113 and the hydraulic movable partition 115. The oil supply port 116, the hydraulic movable partition 115 and the second fixed partition 114 are disposed between the hydraulic movable partition 115 and the first fixed partition 113. A spring 117 that biases in the direction toward the outside, and the discharge pipe 111 that is on one end side outside the cylinder 112, passes through the first fixed partition wall 113 and the second fixed partition wall 114, and exits outside the other end side of the cylinder 112. The valve body driving rod 118 integrated with the hydraulic movable partition wall 115 and the valve body driving rod 118 are fixed to one end of the valve body driving rod 118 so that the discharge pipe 111 is movable from the open state to the closed state. Is fixed to the other end of the valve element driving rod 118, and is accommodated in the air chamber 120 adjacent to the cylinder 112 and movably in the air chamber 120 by air pressure. A pneumatic movable partition 121 and a high pressure air port 122 opened in the air chamber 120 to introduce high pressure air to the other end side of the pneumatic movable partition 121 in the air chamber 120. Obtain.

  A hydraulic pipe 123 is connected to the oil filling port 116, and a working fluid is supplied to the hydraulic pipe 123 via an electromagnetic valve 124. Further, the driving air pipe 102 from the intake manifold 804 is connected to the high-pressure air port 122.

  As shown in FIG. 6A, since the electromagnetic valve 124 is normally inoperative, the working fluid is not supplied to the cylinder 112, and the release control valve 101 is fully opened.

  As shown in FIG. 6B, at the time of supercharging assistance, at the time when the internal pressure of the intake manifold 804 is lower than a predetermined value, the electromagnetic valve 124 is activated and the working fluid is hydraulically coupled with the first fixed partition 113 of the cylinder 112. Since it is introduced between the movable partition wall 115, the hydraulic movable partition wall 115 moves to the other end side (upper right direction in the drawing) of the cylinder 112. Accordingly, the valve body driving rod 118 moves to the other end side of the cylinder 112, and the valve body 119 opens the discharge pipe 111, that is, the release control valve 101 is fully opened. 111 is released.

  As shown in FIG. 6C, when the internal pressure of the intake manifold 804 reaches a predetermined value by supercharging assistance, the pneumatic movable partition wall 121 is pushed into one end side (the lower left direction in the figure) of the cylinder 112, and the release control valve 101. Is slightly smaller than the fully open position. Thereby, the amount of compressed air flowing through the discharge pipe 111 is reduced.

  As shown in FIG. 6D, when the supercharging assistance is finished and the normal operation returns, the operation of the solenoid valve 124 is stopped, and the hydraulic movable partition wall 115 is moved to one end side of the cylinder 112 (lower left in the figure) by the force of the spring 117. The working fluid is discharged from the oil filling port 116. The valve body driving rod 118 moves to one end side of the cylinder 112 and the valve body 119 closes the discharge pipe 111. At this time, since the internal pressure of the intake manifold 804 is still applied to the air chamber 120, the valve body 119 moves smoothly.

  Next, the effect of the supercharging device with supercharging assistance of the present invention will be described.

  As shown in FIG. 7A, in the supercharging device with supercharging assistance of the present invention, when supercharging assistance is performed, the amount of air introduced into the combustion chamber of the engine 801 is without supercharging assistance. Since the output torque rises faster than before, the output torque rises quickly, and when the internal pressure of the intake manifold 804 increases, the opening of the discharge control valve 101 is adjusted, so that the amount of air does not exceed. Therefore, the output torque is almost stabilized at the target value, and there is no overshoot of the engine speed as shown in FIG.

  As shown in FIG. 7 (b), in the supercharging device with supercharging assistance according to the present invention, the opening degree of the discharge control valve 101 is adjusted according to the internal pressure of the intake manifold 804, so that the maximum value of the combustion chamber pressure is increased. Is suppressed, and the pressure in the combustion chamber does not exceed the limit value (not shown) defined for the engine 801.

  As described above, according to the supercharging device with supercharging assistance according to the present invention, the discharge pipe 810 is driven by the air pressure from the intake manifold 804, and the opening degree decreases when the internal pressure of the intake manifold 804 increases. Since the discharge adjustment valve 101 is provided, the turbo lag is eliminated by supercharging assistance, and when the internal pressure of the intake manifold 804 increases during supercharging assistance, the amount of air introduced into the combustion chamber is adjusted to be reduced. The engine rotational speed overshoot is eliminated and the combustion chamber pressure does not exceed the limit value.

  The air amount is adjusted by, for example, providing an air pressure sensor in the intake manifold 804 of a conventional supercharging device with supercharging assistance, attaching an electromagnetic valve whose opening degree can be controlled to the discharge pipe 810, and electronically controlling the electromagnetic valve. Although the release may be controlled, a control delay occurs. In that respect, according to the supercharging device with supercharging assistance according to the present invention, there is no need to provide an air pressure sensor in the intake manifold 804, and the release regulating valve 101 is driven by the internal pressure of the intake manifold 804. There is no delay.

  In the present embodiment, the high-pressure turbocharger 813 is provided in addition to the low-pressure turbocharger 806. However, the present invention is effective even in a configuration having only the low-pressure turbocharger 806.

  In this embodiment, compressed air is discharged to the inlet of the compressor 805 of the low-pressure turbocharger 806 to assist supercharging. However, it may be discharged to the high-pressure side downstream from the outlet of the compressor 805. In this case, the turbo lag can be made even smaller. However, it is necessary to increase the compressed air pressure of the pressure accumulating tank 808 and to devise measures for preventing backflow.

DESCRIPTION OF SYMBOLS 101 Release control valve 102 Drive air piping 111 Release piping 112 Cylinder 113 1st fixed partition 114 Second fixed partition 115 Hydraulic movable partition 116 Oil supply port 117 Spring 118 Valve body drive rod 119 Valve body 120 Air chamber 121 Pneumatic movable partition 122 High-pressure air port 801 Engine 804 Intake manifold 806 Turbocharger 807 Backflow prevention valve 808 Accumulation tank

Claims (2)

A turbocharger in which a turbine rotated by the exhaust of the engine and a compressor that compresses air obtained from the atmosphere via the intake pipe and sends it to the intake manifold; and
A backflow prevention valve that shuts off the intake pipe upstream of the turbocharger during supercharging assistance;
A pressure accumulation tank in which compressed air for supercharging assistance is stored;
It is provided between the intake pipe from the turbocharger to the backflow prevention valve and the accumulator tank, and is driven to open and close by hydraulic pressure, and when it is closed, the compressed air of the accumulator tank is not released, and when it is opened, A release control valve that releases compressed air to the compressor and is driven by air pressure from the intake manifold when released by hydraulic pressure, and the opening degree decreases when the internal pressure of the intake manifold increases;
A drive air pipe for connecting the intake manifold and the release control valve to guide air from the intake manifold to the release control valve;
A supercharging assistance device comprising: Piping,
A cylinder fixed to the pipe;
A first fixed partition and a second fixed partition fixed in the cylinder and facing each other;
A hydraulic movable partition disposed between the first fixed partition and the second fixed partition and movable in the cylinder by hydraulic pressure;
An oil filling port opened in the cylinder to introduce a working fluid between the first fixed partition and the hydraulic movable partition;
A spring disposed between the hydraulic movable partition and the second fixed partition and biasing the hydraulic movable partition toward the first fixed partition;
Valve body drive integrated with the hydraulic movable partition wall, passing through the first fixed partition wall and the second fixed partition wall from the pipe on the outside of one end side of the cylinder and exiting to the outside of the other end side of the cylinder Rod for
A valve body fixed to one end of the valve body driving rod and housed in the pipe so as to be movable from an open state to a closed state;
An air chamber adjacent the leading Symbol cylinder,
A pneumatic movable partition fixed to the other end of the valve element driving rod and housed in the air chamber so as to be movable by air pressure;
Introducing air into the pneumatic moving partition the air chamber so as to urge the said cylinder direction, and the air inlet opened in the air chamber,
With
A release control valve characterized in that when the internal pressure in the air chamber increases during opening, the opening degree decreases.

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