JPH04214117A - Gas flow rate controller - Google Patents

Abstract

PURPOSE:To raise the stability in the minute flow rate control by not using a connecting pipe for the connection of a shutoff valve and a mass flow controller but connecting them directly and making them one body to reduce the volume of the gas staying between the valve body of the shutoff valve and the valve body of a flow rate control valve. CONSTITUTION:The valve body 2 of a shutoff valve and the valve body 4 of a flow rate control valve are installed near to each other to make the shutoff valve 1 and the mass flow controller 3 one body and the volume of a gas reservoir 5 between the valve body 2 of the shutoff valve and the valve body 4 of the flow rate control valve is made small. Accordingly the sudden flow-out of the gas at the moment when the shutoff valve opens is suppressed to minimum and the stability in the flow rate control is increased.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas flow rate control device, and more particularly to a gas flow rate control device equipped with a shutoff valve and a mass flow controller.

0002

2. Description of the Related Art A conventional gas flow rate control device includes a mass flow controller 3, a shutoff valve 1, and a connecting pipe 6 connecting both of them, as shown in a partially sectional front view of FIG.
It has Next, its operation will be explained. The gas outlet side is connected to a device that uses gas, and by opening the valve body 2 in the shutoff valve 1 and opening and closing the flow rate control valve body 4 in the mass flow controller 3 as required, The flow rate from the gas inflow side to the gas outflow side is controlled.

0003

[Problems to be Solved by the Invention] In this conventional gas flow rate control device, since the volume of the gas reservoir 5 between the shutoff valve valve body 2 and the flow rate control valve body 4 is large, it is difficult to shut off the gas as shown in FIG. There is a problem in that the moment the valve 1 opens, the gas that has accumulated in the gas reservoir 5 and whose flow rate cannot be controlled is suddenly released, which deteriorates the stability of minute flow control. In addition, in FIG. 3, the flow rate control amount of the mass flow controller is shown as 0.

0004

[Means for Solving the Problems] The gas flow rate control device of the present invention does not use a connecting pipe to connect the shutoff valve and the mass flow controller, but directly connects the shutoff valve to the mass flow controller and integrates the shutoff valve with the mass flow controller.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings. FIG. 1 is a partially sectional front view showing a gas flow rate control device according to an embodiment of the present invention. In this embodiment, the shutoff valve 1 and the mass flow controller 3 are integrated by mounting the shutoff valve body 2 and the flow rate control valve body 4 close to each other. The volume of the gas reservoir 5 between the two was reduced. The operating timing of each valve is the same as that of a conventional gas flow rate control device.

[0006]

[Effects of the Invention] As explained above, the present invention reduces the volume of the gas reservoir between the mass flow controller and the shutoff valve, so that the sudden outflow of gas at the moment the shutoff valve opens is suppressed to a minute level. This has the effect of increasing the stability of flow control.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional front view showing a gas flow rate control device according to an embodiment of the present invention.

FIG. 2 is a partially sectional front view showing a conventional gas flow rate control device.

FIG. 3 is a graph showing changes in gas flow rate due to opening and closing of a conventional shutoff valve.

[Explanation of symbols]

1 Shutoff valve 2 Shutoff valve body 3 Mass flow controller 4 Valve body for flow rate control 5　　　Gas accumulation 6 Connecting pipe

Claims (1)

[Claims] 1. A gas flow rate control device comprising a shutoff valve that opens and closes a flow to a device that uses gas, and a mass flow controller that controls the flow rate, characterized in that the shutoff valve and the mass flow controller are integrated. gas flow control device.