JPS5878991A - Pneumatic driving machine controller - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a pneumatic drive machine, and particularly to an indant control unit for remotely controlling a main control valve of a pneumatic drive machine.
units are preferred.

In the known control unit, the main supply air flows through a variable restriction to the output port and communicates through another variable restriction to the exhaust port. In combination with co-variable throttles, in the neutral off position, the first throttle, or main throttle, is closed, and the second throttle, or exhaust throttle, is wide open and the output signal is zero. Normally, both throttles are formed as respective tapered sections of the plunger, so that as the plunger moves, the main throttle gradually opens, while at the same time the exhaust throttle gradually closes. This control unit allows a small amount of air to be evacuated during every cycle, and the unit remains operational and at limited pressure for the entire operating life.

This configuration provides a variable pressure signal with valve movement. By changing the diameter of the throttle and the number 6, the pressure increase will be small against large valve movements in the initial stage of opening the valve.
Controllability is not a major problem after the drive speed increases slowly. That is, a slight movement of the valve causes the pressure to increase rapidly. Although such responsiveness is acceptable in many cases, it is important to have excellent controllability over the entire range of valve motion.
A control curve with uniform response, which is not available with known variable throttle combination valve units, is desirable.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a control unit that provides excellent control over the entire range of movement of a valve.

The control unit for remote control of the main valve of a pneumatic drive machine according to the invention has a fixed control orifice between the main supply connection and the output connection and a variable orifice between the output connection and the exhaust point.

In a preferred embodiment, the fixed control orifice and variable orifice are formed by parallel and tapered portions of the spunil. The taper of the spool should be 5° or less, preferably 1°.
shall be. The spool can also be slid directly axially, or a lever pivoted on the housing of the control unit can contact the plunger end projecting from the housing.

With a fixed control orifice, pressure is applied to the output of the valve immediately upon actuation of the lever, the advantage of which is that the operator does not feel the initial pressure caused by the main valve's closing seal.

The other nine embodiments balance the plunger and prevent the unit from opening suddenly during the initial movement. The plunger is spring-backed to the neutral position, where the main supply is cut off from the output connection and the exhaust taper is wide open to communicate with the exhaust.

Embodiments and drawings illustrating the present invention will be described. .

The response curve shown in FIG. 1 shows the relationship between the valve movement vt and the output pressure Po of a known remote control unit having an interconnected tapered inlet restriction and a tapered exhaust restriction.

At first, the pressure increases gradually for a relatively long movement;
The pressure then increases rapidly. The valve is not valid for the 岑 stroke. It has an effective part Es and an ineffective part Ds. The control unit according to the invention has a smooth response curve, the pressure rises slowly over the entire valve stroke vtf, and the unit can be used effectively. This is shown in FIG. 3, which shows the relationship between the output pressure P and the valve stroke Vt of the control unit of the present invention.

- FIG. 2 shows an indant control valve unit, in which a housing 1 is formed with a main body 3 and a handle 5.

The illustrated dund valve is a 6-station unit.
It is used for overhead running lanes to control six types of movements: rising, falling, stacking stones, sideways left, up and down stops.For this purpose, the unit has six valve units, as shown in the figure. In the cross-sectional view, only three are shown, and the other three are parallel to the valve shown. All the valves have a similar structure, but in the example shown, the upper two sets are button-operated, and the lower one is operated by buttons. The set is lever operated.

The lower set controls the hoist's raising and lowering, and the levers provide precise valve control.

For convenience, the uppermost valve 7 will be described in detail.

A stepped hole 9 is machined in the main body 3, and the main spool 11 is engaged within the small diameter portion of the stepped hole 9. The spool 11 is slidable axially within the bore 9, and the turf 9 portion 13 cooperates with the small diameter portion of the bore 9 to form a variable orifice. The spool is provided with a parallel portion 15 forming a fixed orifice 51 for the small diameter hole 9, and the spool 11 forms a small diameter portion between the parallel portion and the turf 9 portion. A stepped portion 17 formed between the small diameter portion and the large diameter portion of the hole 9 forms a valve seat on which a valve member 19 in the form of an O-ring seal attached to the spool is seated. The main air supply inlet port 21 opens into the larger diameter portion of the hole 90 and the output connection 23 opens into the smaller diameter portion of the hole 9 .

When the spool is in the position shown, air pressure is applied to the closing member 19.
The valve closing member contacts the valve seat 17 and isolates the main air supply inlet from the output connection; in this position the variable orifice is fully open and the output connection is connected to the exhaust. communicate.

The end 25 of the spool 11 protrudes from the valve body 3 and is fitted with a button which allows it to be moved in the axial direction of the spool. Hole 26 of the spool end i-plug 27 opposite the button
It is in sealing engagement within and is subjected to the action of a return spring 29-. The hole 26 into which the return spring 29 is inserted is communicated with the outside air through a gas vent hole 31.

If the spool 11 moves to the left, the closing member 19 opens the valve seat 17 and air flows from the main air inlet via the inlet throttle 51 to the output connection 23. The output connection communicates with the switched main valve to direct air to the drive machine. The air flowing to the output connection is exhausted through a variable orifice, the amount of which is exhausted depending on the position of the valve spool 11. Thus, as the valve spool moves further to the left, the amount of air exhausted decreases, the output pressure increases, and the drive speed increases. The O-ring 33 attached to the valve spool completely blocks the exhaust gas, the main pressure acts on the output, and the drive machine runs at full speed.

The valve spool area is balanced so that the spool does not open suddenly when the valve member is opened, allowing smooth fingertip operation.

[Brief explanation of the drawing]

1 is an illustration of the response curve of a known remote control valve with a tapered inlet and a tapered exhaust, FIG. 2 is a cross-sectional view of a control unit according to the invention, and FIG. 3 is an illustration of the response curve of a remote control unit according to the invention. It is a diagram. 1...Housing 3...Body part 9...Stepped hole 11...Main spool 13...Tenoso part 15...Parallel part 17...Shoulder part (valve seat) 19...
・Valve member 21...Inlet port 23...Output connection part 27...Plug 29...Return spring 51...
・Fixed aperture 51 () C) () 0 lily

Claims (1)

[Claims] 1. In a control unit for remotely controlling the main valve of a pneumatic drive machine, in which a variable orifice is provided between the output connection and the exhaust valve, the main supply connection (21) and A control unit for remote control of a main valve, characterized in that it is provided with a fixed control orifice (51) between it and an output connection part (23). 2. The variable orifice and the fixed orifice (51) are formed by a tapered part (13) and a parallel part (15) of a spool (11) that slides in the axial direction within the housing of the control unit. Control unit as described in section. 3. The control unit according to claim 2, wherein the tapered portion has a taper of 5° or less. 46 one end of the spool protrudes from 71 housing;
4. A control unit according to claim 3, wherein the spool is slid directly or by a lever pivotably pivoted on the control unit housing and in contact with said one end. 5. Engage the spool (11) into the stepped hole (9) formed in the housing, and press the shoulder (17) of the stepped hole (9).
) in cooperation with the main supply connection (21) and the fixed orifice 6
5. The control unit according to claim 4, wherein a valve member (19) is attached to the spool to shut off communication between the spool and the spool. 6. The valve member (19) is attached to the shoulder (17) by a spring (29) that engages in the stepped hole and acts on the spool (11).
The control unit according to claim 5, which presses the control unit. 2. An indant control valve comprising a plurality of control valves according to claims 1 to 6.