JPS609853Y2 - flow controller - Google Patents

Description

[Detailed description of the invention] In a general pneumatic circuit, when a normal speed control valve is used for meter-out control as shown in Figure 6, both sides of the piston that slides air-watertight in the cylinder of the actuator are at atmospheric pressure. There are many cases where pressure is supplied to one side and the piston runs out of control due to the compressibility of the air, resulting in damage to jigs and equipment and even personal injury. .

In order to prevent this piston from running out of control, conventional speed control valves have been used for meter-in control as shown in FIG.

This method has the disadvantage that after the piston reaches the stroke end, there is a delay in pressure transmission time due to pressure being supplied gradually due to meter-in control, and it takes time for the cylinder to obtain the necessary force. .

Furthermore, as shown in FIG. 8, in order to reduce the pressure in the Rondo side pipe to the minimum pressure necessary to restore it and reduce air consumption, a pressure regulating valve 24, a check valve 25, and a speed control valve 26 are installed. A control circuit constructed by .27 etc. was used.

In this method, when the directional switching valve 28 is switched and the piston 30 of the cylinder 29 moves to the left, the pressure PR reduced by the pressure regulating valve 24 is supplied to the load side chamber 31 of the cylinder, and the pressure PR is supplied to the head side. The pressure PH in the chamber 32 gradually decreases as it passes through the variable throttle 33 of the speed control valve 27 and is exhausted from the direction switching valve 28.

Therefore, in order for the piston to move to the left, approximately PH<P
However, since the pressure PH is throttled by the variable throttle 33, the pressure gradually drops, so it takes a long time from when the directional control valve 28 is switched until the piston starts moving, that is, the starting time. There was a drawback.

Here, the purpose of this invention is, first, to enable meter-out control and meter-in control, and to prevent runaway of the piston by meter-in control when the pressure inside the cylinder is atmospheric pressure (see Figure 9). Second, when a normal speed control valve is used meter-in, the pressure transmission time delay is compensated for by the pressure control valve's rapid air supply to prevent time loss. Third, the pressure before and after the piston is The purpose of the present invention is to provide a flow controller that can prevent time loss due to the delay in start-up time due to the difference by the rapid exhaust action of a pressure control valve.

Next, an embodiment of this invention shown in the drawings will be described.

First, in FIG. 1, a main body 1 is provided with ports 2 and 3 for inlet and outlet of compressed air, and there is a through hole 7 that connects these ports 2 and 3 into a passage 4, and this through hole 7 is narrowed. A throttle valve 5 and a check valve 6 operating in parallel with the throttle valve 5 are provided.

The throttle valve 5 consists of a needle 8 inserted into a through hole 7 formed in the main body 1, a threaded rod 9 that moves the needle 8 forward and backward by rotation, and a handle 10 formed at one end of the threaded rod 9. The state in which the opening degree of the needle 8 is adjusted by the rotation of the needle 10 is maintained by tightening the lock nut 11 screwed onto the threaded rod 9 toward the main body 1.

Note that reference numeral 12 is a port, which allows the narrow passage formed between the needle 10 and the through hole 7 to communicate with the passage 4.

A check valve 6 disposed in a parallel working relationship with the throttle valve 5 includes a valve body 13, a pressure regulating screw 14 screwed into the main body 1, and a valve body 13 between the valve body 13 and the pressure regulating screw 14. The valve body 13 is mounted on the valve seat 16 formed in the main body 1, and the pressure regulating spring 15 is compressed.
The area A of the pressure receiving surface 17 toward the port 3 side, and this valve body 13
The area A' of the pressure receiving surface 18 toward the port 2 side formed in the middle of
In relation to this, the latter, that is, the pressure receiving surface 18 is designed to be larger than the pressure receiving surface 17.

As a result, this valve body 13 is opened only by the pressure received from the port 2, and flow in the opposite direction is blocked.

When using the flow controller with the above configuration for meter-in, port 3 should be placed on the inlet side (switching valve side).
In addition, port 2 is set to the outlet side (actuator side), and when used for meter-out, port 2 is set to the inlet side (switching valve side) and port 3 is set to the outlet side (actuator side).

Note that during free flow, port 3 is on the exit side.

FIG. 9 shows a mode of meter-in control when the rod 37 connected to the piston 36 of the cylinder 35 is caused to perform a working stroke loaf (G display) using the flow controller 34 configured as described above as a first measure against runaway of the piston of the actuator. This is an example of a combination of meter-out control using a speed controller.

In this figure, among the pipes 39 and 40 between the directional control valve 38 and the cylinder 35, the flow controller 34 is connected to the pipe 39 communicating with the chamber 41 on the head side of the piston 36.
The first port 3 is connected to the directional control valve 38 side, and the port 2 is connected to the directional control valve 38 side.
is connected to the cylinder 35 side, and a speed control valve 42 is connected meter-out between the flow controller 34 and the directional switching valve 38.

Note that the speed control valve 44 may be disposed meter-out in the pipe line 40 communicating with the rod-side chamber 43 in the cylinder 35.

With the above configuration, when both the chamber 41 on the head side and the chamber 43 on the rod side of the cylinder 35 are at atmospheric pressure, during the working stroke, the pipe is connected from the pressure source 45 through the directional valve 38 by the switching operation of the directional valve 38. The compressed air that has entered 39 flows freely through speed control valve 42 and is introduced into port 3.

Since the compressed air introduced into the port 3 is checked by the valve body 13, the flow rate is adjusted by the throttle valve 5, and the compressed air gradually enters the chamber 41 and pushes the rod 37 via the piston 36.

During this working stroke, if the chamber 43 is at atmospheric pressure, meter-in control is performed by the throttle valve 5, so that the piston does not run out of control.

In addition, when performing a work stroke from a state where the chamber 43 is pressurized, the compressed air from the port 3 gradually flows into the chamber 41 through the throttle valve 5, and the pressure increases. However, since the pressure in the port 2 increases, the valve body 13 is pushed down against the force of the pressure regulating spring 15 and becomes fully open, and the flow controller 34 flows into the chamber 41 with free flow.

Therefore, the pressure inside the chamber 43 is controlled by meter-out because the flow rate is adjusted by the speed control valve 44 and the pressure is exhausted from the directional control valve 38.

During the return stroke (indicated by G') after the work is completed, the directional control valve 38 switches, and the flow passes through the conduit 40 and is supplied into the chamber 43 from the speed control valve 44 in free flow.

At this time, the compressed air in the chamber 41 on the discharge side pushes open the valve body 13 in the flow controller 34 and becomes a free flow, and the flow rate is adjusted by the speed control valve 42, that is, it is discharged under meter-out control. It is.

When the pressure inside the chamber 41 is PH and the pressure inside the chamber 43 is PR, when the pressure inside each chamber 41 and 43 during the working stroke is atmospheric pressure, when the inside of the chamber 43 is pressurized during the working stroke, and Each chamber 41 during the return stroke.
Figures 10, 11, and 12 show the relationship between the pressure inside 43, the stroke of the piston, and time, respectively. In Figure 10, a indicates the movement of the piston, and PH and PR are This shows the change in pressure within each chamber 41, 43.

Here, dotted line P'H. P'R indicates the pressure curves of the head side 49 and load side chamber 50 of the cylinder 48 when the normal speed control valves 46 and 47 are used in a meter-out mode in FIG. 6, and a Compared with the device according to this invention, the pressure changes suddenly and presents an unstable condition, and the movement of the piston 51 changes rapidly in a short period of time.

In other words, this indicates that the piston is running out of control at high speed.

On the other hand, when pressure is applied to each of the chambers 43 and 41 as in the case of FIGS. 11 and 12, the conventional embodiment shown in FIG. 6 and the present invention do not provide stable control. It shows the situation.

As a second measure against actuator piston runaway,
FIG. 2 diagrammatically shows the case of meter-in control of the actuator.

In this figure, a flow controller 34 of this invention and a normal speed M control valve 53 are meter-in controlled in pipes 22 and 23 connected to a piston 21 that partitions the inside of a cylinder 20 of an actuator 19, respectively. It is interposed as shown in the figure so that

That is, in this case, the flow controller 3 is connected to the pipe line 22.
4 is connected so that its port 2 is on the cylinder 20 side.

In this case, when the pressure on the head side is P□ and the pressure on the rod side is P2, the movement of the piston 22 in the cylinder 20 to the right and the change in the pressures P and P2 in the cylinder 20 are expressed as follows: Figure 3 shows what happened.

In this figure, due to the switching operation of the directional control valve 54, the pressure source 55 passes through the directional control valve 54 to the flow controller 3.
Since the compressed air introduced into the port 3 of the cylinder 2o is checked by the valve body 13, its flow rate is controlled by the throttle valve 5 and enters the chamber 55 on the head side of the cylinder 2o, moving the piston 25 to the right.

During this stroke, even if the rod-side chamber 56 is at atmospheric pressure, meter-in control is used, so the speed is controlled by the throttle valve 5, and runaway of the piston does not occur.

When the piston 21 reaches the stroke end, the chamber 5
5 is introduced with the flow rate adjusted by the throttle valve 5, so it gradually rises to point a. Therefore, the pressure on the port 2 side also rises, so the valve body 13 resists the force of the pressure regulating spring 15. is pushed down, the valve body 13 and the valve seat 16 open, and the compressed air on the port 3 side is rapidly supplied into the head side chamber 55, and the pressure rises to point b.

Here, the dotted line P□' shows the pressure curve when the normal speed control valve in Fig. 7 is used in meter-in mode, and compared to the pressure curve based on this invention, the piston reaches the stroke end. The pressure transmission time after this invention is the same as that of the flow controller 34 of this invention, which uses a normal speed control valve.
There is a pressure transmission delay of 12-11 compared to using the .

Next, FIG. 4 diagrammatically shows the state in which the flow controller 34 of this invention is used for meter-out in order to prevent wasted energy by reducing air consumption.

In this figure, the piston 6 is connected to the piston 59, 60 between the directional control valve 57 and the cylinder 58 of the actuator.
The flow controller 34 of the present invention is connected to the conduit 59 communicating with the chamber 62 on the head side of the device 1 in a meter-out manner.

That is, in this case, port 2 in FIG. 1 is connected to the directional control valve 57 side, and port 3 to the cylinder 58 side.

In addition, a pressure regulating valve 64, a check valve 65, and a speed control valve 66 are respectively arranged in the pipe line 60 communicating with the rod-side chamber 63 in the cylinder 32 as shown in the drawing.

In the above configuration, during the return stroke in which the piston 61 of the cylinder 58 moves to the left, compressed air from the air source 67 passes through the directional control valve 57 and passes through the pipe 60 to the chamber 63.
In this case, the compressed air in the chamber 62 resists the force of the pressure regulating spring 15 in which the pressure in the chamber 62 is set in the flow controller 34. the valve body 13 is pushed down,
The valve body 13 and the valve seat 16 open to rapidly exhaust air.

When the pressure in the chamber 62 decreases due to rapid exhaust, the valve body 13 is pushed up by the force of the pressure regulating spring 15 and sits on the valve seat 16, and the flow rate is adjusted only by the throttle valve 5, that is, meter-out control is performed. It is then discharged.

Assuming that the pressure in the chamber 62 is P□ and the pressure in the chamber 63 is P2, the change in the pressure in each chamber 62, 63 and the movement of the piston to the left during the return stroke is shown in the fifth figure. In Fig. 5, b indicates the movement of the piston, and P1 and P2 indicate the pressure transition in each chamber 62, 63, and the dotted line PH indicates FIG. 8 shows a pressure curve corresponding to the above-mentioned P1 when a normal speed control valve 27 is used in the pipe line of the head side chamber 32, and the corresponding movement of the piston is indicated by b'.

That is, when using the normal speed control valve 27,
There is a piston stop time called color, and it takes a long time from when the directional control valve 28 is switched until the piston starts moving, resulting in a time loss during the work.

According to the configuration of the present invention, a normal speed control valve is subjected to meter-out control, and the flow controller of this invention is combined with meter-in to prevent piston runaway, and by using meter-in control, pressure is controlled. By opening and closing the valve body in response, the delay in pressure transmission time at the stroke end, which is a drawback of meter-in control, is prevented.

In addition, when used in a meter-out control mode, the rapid exhaust caused by the operation of the valve body has the advantage that delays in starting time due to pressure differences before and after the piston can be eliminated.

[Brief explanation of the drawing]

In the figure, Fig. 1 is a vertical sectional view of one embodiment of the flow controller of this invention, Fig. 2 is a circuit diagram when the flow controller of this invention is used for meter-in, and Fig. 3 is the same as shown in Fig. 2. Figure 4 is a pressure-hour diagram showing the stroke of the piston and the change in pressure in the cylinder in the circuit configuration, and Figure 4 is a circuit diagram when the flow controller of this invention is used for meter-out. Figure 6 is a pressure-hour diagram showing the piston stroke and the change in pressure in the cylinder in the circuit configuration shown in Figure 6. Figure 6 is a circuit diagram of a conventional example when a normal speed control valve is used for meter-out control. Figure 7 is a circuit diagram of a conventional example when a normal speed control valve is used for meter-in control, Figure 8 is a circuit diagram of a conventional example aimed at reducing air consumption, and Figure 9 is the flow of the present proposal. Figures 10, 11, and 12 are circuit examples when the controller is used to prevent piston runaway.
Respectively, the pressure and stroke hour line are when the rond side chamber is not pressurized during the working stroke, when the rod chamber is pressurized, and when the head side chamber is pressurized during the return stroke. It is a diagram. In the figure, 1... main body, 2, 3...
... Port, 4 ... Passage, 5 ... Throttle valve, 6 ... Check valve, 7 ... Through hole,
8... Needle, 9... Threaded rod, i
o------Handle, 11...Lock nut, 12...Port, 13...Valve body, 1
4... Pressure regulating screw, 15... Pressure regulating spring, 16... Valve seat, 17, 18...
... Pressure receiving surface, 19 ... Actuator, 20
...Cylinder, 21 ...Zeston, 22
．． 23...tL34--Flow controller, 35...Cylinder, 36...
Piston, 37...Rod, 38...
Directional switching valve, 39, 40...Pipeline, 41...
. . . Chamber, 42 . . . Speed control valve.

Claims (1)

[Scope of utility model registration request] A main body 1 having two ports 2 and 3 for air entry and exit, and a passage 4 that communicates these ports 2 and 3, a throttle valve 5 that narrows the passage 4 in the main body 1, and this throttle valve 5. The area of the pressure receiving surface 18 of the valve body 13 of the check valve 6 with respect to the port 2 on the outlet side, that is, the actuator side when used for meter-in, is , the area of the pressure receiving surface 17 of the valve body 13 is made larger than the area of the pressure receiving surface 17 of the valve body 13 for the outlet side, that is, the actuator side when used for meter-out, and the outlet side for free flow, so that the pressure on the port 2 side is maintained at a predetermined level. A flow controller that functions as a shutoff valve when the pressure is below a predetermined pressure, and allows communication between ports 2 and 3 when the pressure on the port 2 side exceeds a predetermined pressure.