DE2228040A1 - CONTROL VALVE - Google Patents

Description

Dr.-lng. E. BERKENFELD · Dipl.-Ing. H. BERKENFELD, patent attorneys, Cologne Attachment file number

on the submission of May 19, 1972 vA // Nam «d. Note Commercial Shearing, Inc.

Control valve

The invention relates to control valves, in particular to pressure-compensated control valves for liquid-operated ones Systems, and is an improvement on the control valve design disclosed in US Pat 3.565.110 is described.

It has long been recognized that, for the speed of a load moving device, it is desirable to that it is the same regardless of the size of the load. In liquid operated systems this means that the amount of liquid flowing in the system must be the same regardless of the size of the load. This can can of course be manually regulated to some extent by manually moving the valve around the same thing adapt to changing load conditions. However, manual control is quite difficult and requires one extremely skilled operator, as well as the constant attention of the same.

The invention provides a valve construction which automatically adjusts the position of the valve as a function of the load regulates in order to maintain a constant flow of the amount of liquid, as it is in the construction according to of the above-mentioned patent specification is the case. With this design there are situations in which the compensator Receives an incorrect signal as a result of the movement of the balls in the ball chambers of the directional valve.

A directional control valve for the optional actuation of a C 20/38 309813/0710

2228Q4Q

Fluid motor with a regulated speed is characterized according to the invention by inlet and outlet openings and through first and second openings for communication with opposite sides of the liquid motor, through a Pressure equalizing valve having an axial bore, an inlet port that communicates with the inlet port of the control valve is connected, an outlet port, a pressure sensing port, a spool movable in the axial bore and means for urging the spool valve to a position usually diverting the outlet port from the inlet port shuts off and which partially shuts off the A inlet port from the inlet port of the control valve, the Spool valve has opposing surfaces that correspond to the fluid pressure at the inlet port and the fluid pressure are subjected to the pressure sensing opening which cooperates with the printing device, and wherein the Control slide in the pressure compensation valve corresponding to a liquid pressure differential between its inlet opening and the pressure sensing port is movable to connect the inlet port with the return port for bypassing the printing fluid from the directional control valve and thereby the input flow through the directional control valve to regulate one of the work openings. The directional control valve is preferably provided with a control slide, movable in a bore with the spool being hollow at each end to form chambers passing through the wall of the control slide can be optionally connected to the inlet opening, the working openings and the outlet opening can, as well as by cooperating grooves in the bore of the directional control valve and the same in the control slide with the pressure sensing port of the pressure compensating valve.

The invention therefore relates to a pressure-compensated directional control valve which supplies a constant amount of liquid can and the inlet and outlet ports, as well as first and

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second openings for connection with the opposite ones Has sides of a liquid motor, a longitudinal bore in the control valve and a control slide movable in the bore, which at. each end is hollow to form chambers which are selectively interconnected and through the Wall of the control slide with the inlet openings, the outlet openings, the working openings and a pair at a distance lying grooves that surround the control slide, three spaced annular grooves in the valve wall, which with the Grooves in the spool are in communication, and a pressure sensing port, which with the central groove in the valve wall is in communication, as well as a pressure relief valve having an axial bore, an inlet port which is connected to the Inlet port of the control valve is connected, an outlet port, which is connected to the outlet port of the control valve, a pressure sensing port, a control slide, the is movable in the bore and pushed into a position in which the inlet port is usually separated from the outlet port is shut off, the spool having opposing surfaces that reflect the fluid pressure at the inlet port and are subjected to the liquid pressure at the pressure sensing port cooperating with the pressure means, and wherein the spool corresponds to a fluid pressure differential between its inlet port and the pressure sensing opening of the directional control valve is to the inlet port with the outlet port for the purpose of diverting the pressure fluid from the directional control valve connect and thereby regulate the inlet flow through the directional control valve to a working port.

In the general description above, there are certain Objects, features and advantages of the invention specified. Further objects, features and advantages of the invention result can be seen from the description below with reference to the drawings in which:

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1 schematically shows a vertical longitudinal section through a directional control valve and a pressure compensation valve according to the invention,

Fig. 2 is a horizontal longitudinal section along the line II -

II of Figure 1,

Fig. 3 is a horizontal longitudinal section along the line III -

III of Figure 1 and

Fig. 4 'shows a horizontal longitudinal section along the line IV -

IV of FIG. 1.

In the drawings, the housing 10 of a directional control valve is shown, which has an axial bore 11 with a control slide 12. The housing is provided with spaced outlet chambers 13 and 14 adjoining each end and crossing the bore 11 and with two working chambers 15 and 16, one of which is adjacent to each outlet chamber and each can be connected to opposite sides of a liquid motor . Inlet chambers 17 and 17, which are spaced apart, are arranged between the two working chambers. The spool 12 is hollow at each end to form a pair of spaced inner chambers 19 and 20 which extend in the axial direction of the spool and through an axial passage 21, and with spherical chambers 22 and 23 at each end of the passage are connected. The Kugelakmmern are provided with freely movable balls 24 and 25, ν held by plug 26 and 27 in place, which are screwed into the ends of the chambers 22, 23 and each of which is provided with a passage 26a and 27a. Each of the chambers 22 and 23 is provided with passages 22a and 23a which extend in the radial direction to the circumference of the control slide. The chamber 20 is provided with two sets of radial openings 20a, 20b and the chamber 19 is provided with corresponding sets of radial openings

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openings 19a, 19b provided. The openings 19a and 20a lie on a helical line so that their center lines do not lie on the same circumferential line. The openings 19b and 20b are separated from the openings 19a and 20a within the chamber by check valves 19c and 20c which are actuated by springs 19d and 20d. The control slide is surrounded by annular grooves 22b and 23b which are in communication with the passages 22a and 23a of the control slide. When the control slide is shifted to the right according to FIG. At the same time, the openings 19a against the inlet chamber 17 and the openings 19b against the working chamber 15 are opened. When the spool is moved, the openings 19a and 20a are opened sequentially against the corresponding chamber in order to provide a slowly increasing flow of liquid into the corresponding chamber in a throttled manner. This liquid then opens the corresponding check valve 19c and 19d, which enables the liquid in the chamber 19 to flow into the working chamber 15 and from there to one side of a liquid motor (not shown). On the other hand, the liquid is discharged on the opposite side of the liquid motor into the working chamber 16 and from there through the openings 20a and the check valve 20c into the outlet chamber 14 to close the passage 21. The passage 23a is then isolated. Moving the spool from the neutral position in the opposite direction reverses the flow of liquid. The valve housing is provided with annular grooves 30, 3) and 32. When the spool is in the neutral position, these annular grooves are open to the radial passages 22a and 23a so that the liquid moves freely between them and the grooves 22b and 23b in the spool

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emotional. The groove 31 is connected to a radial passage 33 which extends to the outside of the housing 10. The grooves 30 and 32 are connected to passages 34 and 35, respectively, which extend at an angle to the outside of the housing 10 and open into a common opening 36 there.

The housing 40 of the pressure compensation valve has a bore 41 which is closed by a cap 42 which is attached to a End is screwed into the bore, and through a cap 43, which is screwed into the bore at the opposite end is. The bore 41 is crossed by outlet chambers 44 and 45, which at each end by a U-shaped Passage 46 are interconnected. Inlet or high pressure chambers 47 and 48 cross the bore between the outlet chambers. A pressure sensing passage 49 crosses the bore 41 between the inlet chambers 47 and 48. The cap 43 extends passes through the outlet chamber 45 and is provided with a groove 43a which allows the liquid to move freely around the Cap in the chamber 45 allows. A control slide 50 is freely movable in the bore 41 and is pressed against the cap 42 pressed by a spring 51, one end of which rests against the cap 43 and the other end against the control slide 50. The spool 1 is hollow from the end adjacent to the cap 42 to one of its opposite ends Spaced end to form an inner axial chamber 52. Radial openings 53 in the wall of the control slide 50, which are spaced apart in the axial direction, connect the chamber 52 with the inlet chamber 48. Similar radial openings 54 in the wall of the control slide 50, which are spaced apart from one another in the axial direction the chamber 52 with the inlet chamber 47. The control slide 50 is surrounded by an annular groove 55, which with the passage 49 communicates. The groove 55 is with the area connected between the cap 43 and the spool 50 by an axially directed passage 56 which leads to the chamber 52 is parallel.

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The outlet section 60 has a bore 61 which is closed at one end by the screw cap 62, which holds the base 63 of the pressure relief valve in place. This base part 63 is provided with an axial bore 64, which communicates with the outlet chamber 65 through the radial passage 66. The pressure relief valve 67 in the Bore 61 is pressed against base part 63 by spring 68. The housing of the pressure relief valve 67 is parallel Bores 69 are provided which establish the connection between the inlet chambers 70 and 71. The pressure relief valve 67 is pilot controlled and is regulated by the pilot valve 72, which opens into the outlet chamber 73. The outlet chambers 65 and 73 are connected by the U-shaped passage 74. An angled passage 75 extends south from the opening 76 to the outlet chamber 73. The opening 76 is intended for connection with the opening 36 of the directional control valve.

The operation of the valve construction according to the invention is as follows:

In Fig. 1 is the directional control valve 10, pressure compensation valve 40 and outlet section 60 shown in the position when no pressurized fluid to act comes. When the inlet port 100 is supplied with pressure fluid from a pump (not shown) the chambers 48, 18, 71, 70, 17 and 47 together with the inner chamber 52 of the control slide 50 are pressurized. Of the Pressure in the chamber 52 causes the control slide 50 to move to the left as shown in FIG. 1 to move out of the open The end of the chamber 52 is discharged into the chamber 44 and then through the chambers 14 and 73 to the outlet and back to the (not shown) Container. If the control slide is moved to the right, for example according to FIG. 1, the liquid arrives through the openings 19a into the chamber 19, as well as through the check valve 19c and the openings 19b into the ar-

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working chamber 15 and from there to one side of one to be actuated Liquid motor. The position of the control slide 12 in the bore 11 initially regulates the amount of liquid the size and number of the openings 19a which are opened towards the chamber 17. Set the position within a short time of the control slide and the openings 19a produce an equivalent opening, whether a flow is present or not. this produces essentially the same stable pressure in the chamber 19 and at the spring end of the control slide 50, the at inlet port 100 and in chamber 52. : The spool 50 is therefore by the spring 51 after right to begin shutting off flow into outlet chamber 44. The ones from the working chamber 16 Returning liquid enters the openings 20a and passes through the check valve 20c and the openings 20b into the outlet chamber 14. At the same time the passage 22a comes into communication with the passage 49 when the control slide is moved to the right, so that the area behind the control slide 50, in which the spring 51 is effective, under the the same pressure is set that prevails in the chamber 19 of the control slide 12. When the pressure increases, it moves the control slide 50 to the right, whereby the liquid flowing into the outlet chamber 44 is cut off, so that the pressure of the liquid in the inlet chamber 17 is increased to ensure a constant flow through the working chamber 15 to maintain. On the other hand, when the pressure in the chamber 19 decreases, the pressure behind the spool also decreases 50 from and the same moves to the left, so that the amount of liquid diverted into the outlet chamber 44 increases will. As soon as the control slide 12 is set to a given volume, the change in the pressure drop regulates the Amount of liquid that flows into the pressure equalization valve 40 * is emptied so that the amount of liquid supplied to the working chamber is constant. When the spool 12 is completely «" Is open, i.e. moved to the left or right,

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100 % of the liquid reaches the working chamber and the control slide 50 is in the rightmost position so that no liquid is diverted. Under these pressures, both balls 24 and 25 close off the passage 21 from the chamber 19 to the chamber 20.

If a second control valve is switched into the system, as is possible according to the invention, then that will Compensates valve which demands the highest pressure. Assuming that there are two identical control valves which correspond to valve 10 and assuming 189.3 liters of hydraulic fluid under pressure of 210 kp / cm are available and that 75.7 1 hydraulic

Liquid under a pressure of 70 kgf / cm is supplied from the inlet port 100 to the working chamber 15 of the first valve be, as well as if it is assumed that the next valve is operated and that at the working chamber 16 & es Second valve a pressure of 140 kp / cm is required then this will cause the liquid in the chamber 20 through passage 23a to opening 36 of the previous one Valve arrives. The liquid also flows down through the passage 35 to the passage 21 so that the balls 24 and 25 are moved to close the passages 26a and 27a. The pressure then passes through passage 22a, the passage 49, the groove 55 and the passage 56 in the area containing the spring 51 behind the control slide 50, so that the same is moved to the right, whereby the diversion to the outlet chamber 44 is completed until the pressure in the passage

2
let 48, 18 and 71 reach 140 kgf / cm. The control slide 50 then remains subject to the regulation of the pressure drop in the second control valve. At this point in time the first valve must be throttled manually in order to regulate the amount of liquid.

If the conditions change so that the first valve requires the higher pressure, then the same takes over the control.

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eration of the spool 50, which maintains a constant flow rate while the second valve is operated manually will. The control valve, which works under the highest pressure, is therefore automatically pressure-compensated, and the other valve or valves in the system are manually operated.

The invention is not limited to the illustrated and described exemplary embodiment, the various Can experience changes without departing from the scope of the invention.

Claims

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Claims (5)

Dr.-lng. E. BERKENFELD · Dipl .-! Ng. H. BkrkiCENFELD, patent attorneys, Cologne Attachment file number on the submission of May 19, 1972 vA // Name d. At the". Commercial Shearing, Inc. PATENT CLAIMS Pressure-compensated directional control valve, consisting of a directional control valve for the optional actuation of a fluid motor with regulated speed, characterized by inlet and outlet openings and first and second openings in connection with opposite sides of the fluid motor, through a longitudinal bore in the control valve, through a control slide which is movable in the bore which is hollow at each end to form spaced chambers which are selectively interconnected and defined through the wall of the spool with the inlet ports, the outlet ports, the working ports and with a pair of spaced grooves surrounding the spool, through three spaced annular grooves in the valve wall, which are in communication with the grooves in the control slide, through a pressure sensing opening which is in communication with the central groove in the valve wall, through a pressure compensation valve that has an axial bore comprises, an inlet port which is connected to the inlet port of the control valve, an outlet port which is connected to the outlet port of the control valve, a pressure sensing port which is in communication with the pressure sensing port of the directional control valve, a spool which is movable in the axial bore, and means for urging the spool into a position which ordinarily blocks the outlet from the inlet port, the spool having opposing surfaces that reflect the fluid pressure at the tsvrs inlet port and the fluid pressure at the pressure outlet, respectively. c Mj9i 309813/0 710 Sensing opening are subjected, which cooperates with the pressure device, and wherein the control slide according to the Fluid pressure differential movable between its inlet port and the pressure sensing port of the directional control valve is to connect the inlet and outlet ports for the purpose of diverting the pressure fluid and thereby the inlet flow through the directional control valve to one of the working ports to regulate. 2.. Control valve according to Claim 1, characterized in that the directional control valve is provided with a control slide which is movable in a bore, that the spool is hollow at each end to form chambers which through the wall of the control spool * »s optionally with the Inlet port, with the working ports and with the outlet port in communication, as well as with the pressure sensing port of the pressure compensation valve through one of the annular grooves in the control slide and the pressure sensing opening of the directional control valve. 3 \ Control valve according to claim 2, characterized in that the control slide of the directional control valve is connected to the pressure sensing opening through the annular grooves in the control slide and in the valve wall, as well as the two chambers in the neutral position and through a passage in each chamber in every working position. 4. Control valve according to claim 3, characterized in that the passages in each chamber with the outlet opening in Connect when the spool is in the neutral position. 5. Control valve according to claim 1, characterized in that the control slide of the pressure compensation valve is high and C 20/38 309813/0710 one end is open, that is, the hollow part of the control slide with the inlet opening of both the directional control valve and the pressure compensation valve through openings in the Sidewall communicates and that the control slide discharges through its open end to the outlet opening when the pressure in the chamber is greater than that of the pressure device and ah the pressure sensing openings. 3098 13/0710