JPS6025014Y2 - Flow control valve used in meter-out type - Google Patents

Description

[Detailed description of the invention] Applying air pressure to a piston slidably fitted in a cylinder and extracting the movement of the piston caused by this pressure as work via a rod attached to the piston, This is widely practiced, but in this case, the required output of the cylinder is determined by the pressure that causes the piston to stroke to do work (generally pressure on the head side), and the stroke pressure that causes the piston to return (pressure on the rod side) is determined by , the minimum pressure required for return should be sufficient.

However, in a normal usage example, as shown in FIG. 4, after the pressure is adjusted by the pressure reducing valve 33, the directional control valve
As a result, both the head side 36 and rod side 37 of the cylinder 35 are operated by applying the same pressure, which means that energy is wasted on the return side.

Therefore, in order to prevent this wasteful energy consumption, conventionally, a control circuit including a pressure regulating valve 38, a check valve 39, a flow control valve 40, etc., as shown in FIG. 5, has been used.

According to this method, in the state shown in FIG. 5, the pressure PM of the head side 42 of the cylinder 41 is introduced from the air source 43 via the switching valve 44 and the flow rate control valve 45.

When the switching valve 44 is switched from this state, the pressure of the air source 43 passes through the flow rate control valve 40 and is introduced into the rod side 46 of the cylinder 41 at the pressure PR reduced by the pressure regulating valve 38, but the pressure PH and PR has a relationship of PH>PR in the initial state when the switching valve 44 is switched.

Therefore, in order for the piston 47 of the cylinder 41 to start moving to the right, the pressure P passes through the flow rate control valve 45 and is exhausted from the switching valve 44, until the force balance between the front and rear of the piston 47, that is, the rod side and the head side, is lost. The pressure must drop.

To state this specifically, the pressure of the air source 43 is
kgf/CF+! , if the pressure PR reduced by the pressure regulating valve 38 is 2*f/cwt, then in the initial state shown in FIG. 5, the pressure PH on the head side 42 of the cylinder 41 is 5*9 f/cn! In order for the piston 47 to start moving to the right, pressure PH must be exhausted from the switching valve 44,
This means that the pressure must drop to at least 2 kgf/cffl or less.

In this way, the pressure PH on the head side 42 is exhausted from the switching valve 44 and the pressure drops, but this exhaust is throttled by the variable throttle 48 for meter-out control of the flow rate regulating valve 45.

Therefore, since the pressure PH gradually decreases, there is a drawback that it takes a long time from when the switching valve 44 is switched until the piston 47 starts moving to the right, that is, the so-called starting time.

As described above, compressible fluids such as air have problems due to their inferior pressure responsiveness compared to incompressible fluids such as oil pressure.

The purpose of this invention is to drive the cylinder by supplying the supply pressure in a free flow into the cylinder in order to solve the above-mentioned drawback of the conventional method, which is the delay in initial startup time. The present invention aims to provide a valve that has a pressure control section for exhausting the cylinder at a meter-out rate, and a function for controlling the speed of the cylinder by adjusting a throttle valve when exhausting at a meter-out.

The basic structure of this invention is that a composite valve consisting of an adjustable spring, offset, and pilot type 2-point/2-position switching valve and a needle valve as a throttle valve is installed in the flow path within the main body. When the pressure in the passage is higher than the pressure set by the spring, it becomes open, and air is supplied into the cylinder with free flow, or the pressure inside the cylinder is rapidly exhausted, and at the same time, when the pressure in the passage is lower than the set pressure, it is in the closed state. , the cylinder internal pressure is controlled by the flow rate using a throttle valve.

Next, this invention will be explained with reference to an embodiment shown in FIGS. 1 and 2.

In Figures 1 and 2, the main body has an inlet/outlet port 2,
3, and a passage 4 connecting these ports 2 and 3 includes a spring, offset, and pilot type two-point/two-position switching valve 5 as a quick exhaust valve, and a needle valve 6 as a throttle valve. A combined composite valve 7 is provided.

First, the composite valve 7 will be explained. A valve body 9 seats against a valve seat 8 formed in the main body 1, and a piston-shaped side wall 1.
A cylindrical wall 11 is formed on the main body 1, and the piston-like side wall 10 slides in an air-tight manner.

A spring 14 is compressed between the piston-shaped side wall 10 and a seat body 13 screw-fitted to an internally threaded cylindrical wall extending from the cylindrical wall 11 .

The pressure on the port 3 side is used as a pilot pressure and is applied to the piston-shaped side wall 10 to separate the valve body 9 from the valve seat 8 against the force of the spring 14 and open the passage 4. The needle valve 6 is combined with the 2-point/2-position switching valve 5 in the following manner.

That is, the distal end portion 16 can move forward and backward within the through hole 15 formed in the central portion of the valve body 9 and the piston-shaped side wall 10, and the distal end portion 16 can move through the horizontal hole 17 formed in the valve body 9 and the A needle 19 is provided to open and close the opening 18 formed between the through hole 15, a threaded portion 20 is provided at the rear end of the needle 19, and this threaded portion 20 is provided on the seat body 13. It is screwed into the threaded hole 21, with its end protruding to the outside, and a turning groove 22 is cut into the end so that it can be turned with a screwdriver or the like.

The flow rate regulating valve having the above configuration is used as a meter-out type, and as shown in FIG. Above port 2
The port 3 is connected to a conduit 27 that communicates with a switching valve (not shown).

A circuit 32 consisting of a variable throttle valve 29, a pressure reducing valve 30, and a check valve 31 formed in parallel with the pressure reducing valve 30 is interposed in the pipe line 28 led out from the rod side of the cylinder 24. will be established.

In this case, when the pressure on the head side is Pl and the pressure on the rod side is P2, the F of the piston 25 in the cylinder 24 is
and F' in both directions and the pressure P in the cylinder 24.
Figure 3 shows the changes in P1 and P2.

Pressure is supplied to the head side of the actuator side 23 in the following manner.

In other words, due to the high supply pressure from the switching valve (not shown),
As shown in FIG. 6, the piston-shaped side wall 10 is pressed, the valve body 9 is fully opened, supply pressure is supplied into the cylinder 24 in a free flow, and the piston 25 is driven.

On the rod side, the exhaust is controlled by a variable throttle valve 29.

When, contrary to the movement of said piston 25 in the direction of the arrow F, the supply of compressed air which causes a movement of this piston 25 in the direction of the force of the arrow F' takes place via the line 28, on the head side the line 27 As shown in FIG. 6, the valve body 9 is fully opened from the port 2, and the passage 4 is rapidly exhausted from the switching valve via the port 3, resulting in a pressure drop.
As shown in the figure, the valve body 9 is pushed down by the force of the spring 14 loaded on the valve body 9, and the valve body 9 is forced onto the valve seat 8, and the fluid flows from port 2 to port 3 through a horizontal hole 17 provided in the valve body 9. The meter-out control is performed by the opening 18 formed between the through hole 15 and the through hole 15.

The degree of opening of the opening 18 is adjusted by moving the needle 19 back and forth.

A comparison of the rightward movement of the piston in the conventional pneumatic circuit configuration shown in Figure 5 and in the pneumatic circuit using the flow rate adjustment valve of this invention as shown in Figure 2 is shown below. FIG. 7, in which a indicates the pressure curve of the pressure P□ on the head side according to this invention;
b shows the movement of the piston 25 in that case.

On the other hand, in the case of the conventional circuit configuration shown in FIG. 5, the pressure drop curve a' of the pressure PH on the head side 42 is
The movement of the piston 47 is as shown by b'.

That is, in the case of this invention, the rapid exhaust valve opens until the pressure is set by the spring 14, and the exhaust is rapidly discharged from the switching valve through the passage 4, so that the pressure rapidly drops from C to d, which reduces the startup time. However, in the case of the conventional circuit configuration, the pressure PH on the head side 42 of the cylinder 41 is reduced to C Since the pressure gradually decreases from to e, it is necessary to allow for a considerable start time and a fairly wide stop time.

In this way, the flow control valve with the pressure control function of rapidly discharging air, as in the configuration of this invention, can significantly shorten the operating time compared to conventional flow control valves, so it is a practical method for improving productivity. Extremely useful.

[Brief explanation of the drawing]

In the drawings, Fig. 1 is a vertical sectional view of one embodiment of this invention, Fig. 2 is a line diagram schematically showing an example of the usage mode, and Fig. 3 is a vertical sectional view of one embodiment of the invention.
A graph showing the pressure fluctuation state in the usage example shown in the figure,
Figures 4 and 5 are diagrams showing examples of conventional circuits, Figure 6 is a vertical sectional view of an example of this invention, and Figure 7 shows a comparison of the operating states of the circuit shown in Figure 2. This is a graph showing. In the figure, 1... main body, 2, 3...
... Port, 4 ... Passage, 5 ... 2-point to 2-position switching valve, 6 ... Throttle valve, 7 ...
...Compound valve, tail...valve seat, 9...valve body,
10... Zestone-shaped side wall, 11... Curved cylindrical wall, 12... Internally threaded cylindrical wall, 13...
・Seat body 1.14...Spring, 15...
...Through hole, 16...Tip, 17...
・Horizontal hole, 18... Opening, 19... Needle, 20... Threaded part, 21... Screw hole, 22...... times Motion groove, 23... Actuator, 24... Cylinder, 25...
... Piston, 26, 27.28 ... Pipeline, 2
9... Variable throttle valve, 30... Pressure reducing valve,
31... Check valve, 32... Valve device, 33... Pressure reducing valve, 34... Directional switching valve, 35... Cylinder, 36... Head side, 37... Rod side, 38... Pressure regulating valve.

Claims (1)

[Claims for Utility Model Registration] 1. A main body having two ports for ingress and egress of air and a passage that communicates these ports, and a quick exhaust valve that can open and close the passage within the main body by pressure on the actuator side. and a composite valve that is combined with a throttle valve that narrows a horizontal hole formed in parallel with the passage in the rapid exhaust valve section, and is used in a meter-out type. 2. The flow rate regulating valve according to claim 1, wherein the throttle valve is a needle valve. 3. The quick exhaust valve is a spring, offset, and pilot type two-point/two-position switching valve with adjustable switching pressure. Flow rate regulating valve according to claim 1 of the utility model registration claim.