DE2115054A1 - Valve for hydraulic or pneumatic systems - Google Patents

Description

Valve for hydraulic or pneumatic systems The invention relates to a valve for hydraulic or pneumatic systems, the one provided with a shaft Valve body axially between a closed position in contact with a seat and a The opening position can be adjusted away from the seat, with a valve connection on an annular channel surrounding the valve body on one side of the seat and at least another valve connection on another, on the other side of the seat arranged and the shaft surrounding annular channel is provided.

Valves are required in hydraulic and pneumatic systems which work particularly quickly and can be used as seat valves. Included there must be no leakage of oil and it must be ensured that the Valves, for example by means of electromagnets, are light, fast, reliable and quiet let switch. There is a defect in most of the poppet valves on the market now that it is difficult to equalize the pressure. Pressure equalization is necessary, however, in order to operate the seat valves without hydraulic pilot control with an electromagnet or a mechanical control device of low force to be able to drive. This problem occurs especially with oil hydraulics, where mostly high pressures are used. The electromagnet must have such a great force that it is able to handle the valve body pressed into the valve seat by the oil pressure lead out of the closed position. To illustrate what powers are required, it should be mentioned, for example, that with a diameter of the valve body of 8 mm, which corresponds to an area of 0.5 cm2, at an operating pressure of 100 bar a force of 50 kg is required to create a small opening gap. The opening gap only increases when there is pressure compensation in the entire control system has taken place. This understandably delays the switching time.

The aim of the invention is now to remedy this and in particular a To create directional seat valve in which in a simple manner and without special Measures a pressure equalization can be achieved, so that a proper switching of the valve even with small, easily applied by-electromagnets Forces is guaranteed. To solve this problem, according to the invention proposed a valve of the type mentioned that the one with the valve body connected shaft of the valve at its free end facing away from the valve body one facing the valve body in flow connection with the annular channel surrounding the shaft has standing printing surface.

This pressure surface can preferably be formed in that the valve stem has a thickening at the end remote from the valve body. In some cases it can be useful if the valve stem then gradually increases in diameter merges into the thickening, whereby possibly

der'Ventilschaft adjoining the valve body to generate a gradual transition can also be thickened.

In the case of a valve designed in this way, it is appropriately designed of the ring channel surrounding the shaft possible to achieve that the pressure medium simultaneously acts on the pressure surface and the valve body and thereby opposed to the valve element consisting of the valve body and stem exerts directed forces, which depending on the choice of the size of the pressure surface opposite the valve element cancel each other out or accelerate the movement of the valve element in one direction or the other. Thanks to this possibility On the one hand, the valve can be adjusted without difficulty so that it is with the available force of the electromagnet or some other actuating element can be operated without further ado. On the other hand, a flawless adaptation to the required and desired control speed possible.

The manufacture of the valve body and stem with a thickening The valve element is then particularly simple when it is on according to the invention the valve body a bolt is arranged on which at least one of the thickened Shaft part forming sleeve is placed. Usually, however, the training be such that on the bolt one of the valve body extending and the entire Shaft including the thickening-forming sleeve is placed, which then e.g.

be fixed by means of a nut screwed onto the bolt can.

A proposal of independent inventive importance lies in that a ball is used as the valve body Shank held by means of a bolt, the bolt in a bore in the ball is attached. In this training, as a standard valve body with the Method of the ball bearing industry obtained Kugehndien, which subsequently with a blind hole or a through hole for receiving at least the end of a bolt.

The use of a ball as a valve body brings about a reduction the flow resistance and good adaptability to different valve seat diameters. The particular advantage, however, is that a geometrically precisely formed Ball in each spatial offset position perfectly sealing to one accordingly spherical surface of the associated valve seat rests. In doing so, of the invention through the valve stem damping and guidance of the valve body forming sphere.

A valve has proven to be particularly versatile in the - according to a further feature of the invention - the valve body with two axially opposite seat surfaces cooperates and two opposite, respectively one Bears shafts having pressure surfaces, each of which has an annular channel with a valve connection assigned.

It is a so-called 3/2-way seat valve that a perfect pressure equalization by the two, on different sides of the valve body arranged pressure surfaces is achieved.

Finally, according to the invention, it is provided that in a housing two independently movable valve elements made of valve body and two opposite shafts are arranged together with the associated ring channels, wherein preferably the valve elements are arranged approximately coaxially at a distance from one another can. In this case, to simplify operation, between the valve elements a return spring acting on both elements can be provided, so that only a corresponding drive element, for example, to move out of the rest position an electromagnet, is required. One provided with two such valve elements Valve allows - with the appropriate connection of its ring channels to an actuating cylinder od the like. Particularly peculiar and appropriate types of control that continue are explained in more detail below.

Further features, details and advantages of the invention result from the following description of preferred exemplary embodiments based on the Drawing.

The figures show: FIG. 1 a 3/2-way seat valve designed according to the invention in longitudinal section; Figures 2a to 2d schematically an upstream of an adjusting cylinder 4/4-way seat valve in the four operating positions; Figure 3a to 3d the valve 2a to 2d, but with a different connection of the actuating cylinder and of the pressure lines in the four operating positions and FIG. 4 is a section through a hydraulic control unit with a mechanically controlled, according to the invention trained valve.

The valve according to FIG. 1 has, for example, a rectangular or square housing 1, which with a central bore 2 for receiving the parts forming the actual valve and the valve stem 3 are used. With the Housing 1 is, for example, with the help of screw bolts 4 with a return spring 5 equipped electromagnet 6 connected, the housing also has transversely to Axis of the bore 2 running on screw connections 7, 8 and 9, with the illustrated Embodiment the connection 7 for the pressure line, the connection 8 is intended for the return and connection 9 for the consumer. It is the training chosen so that a 3/2-way seat valve is created.

The valve stem 3 has the valve body 10 with the valve seats 11, 12 cooperates, one provided with a central bore 13, on both sides flattened ball on. The bore 13 of the ball 10 is penetrated by a bolt 14, which Part of a valve stem located above the ball 10 in FIG. 1 at the same time 15 forming rotary part. The like. Is. The valve stem 15 has, as the drawing clearly shows a thickening 16 and a thinned section 17, the thinned portion 17 gradually forming a pressure surface 18 in the compression 16 and merges into the ball 10 at the other end.

At the upper end of the shaft 15, a projection 19 is provided on the the armature 20 of the electromagnet 6 or its return spring 5 for axial displacement of the valve stem 3 act.

The valve stem 21 located below the ball 10 in FIG. 1 corresponds in its external shape in the illustrated embodiment, the valve stem 15. The thickening 16 'and the thinned portion 17', however, are one on one the bolt 14 pushed-on sleeve 22 is formed. The ball 10 and the sleeve 22 are on the bolt 14 by means of a Mother 23 fpstetzt. Of course it would also easily be possible to match the upper shaft 15 to the lower one Shank 21 by sliding a sleeve onto both the shank 15 and to produce the shaft 21 and the ball 10 penetrating bolts.

The two seats 11, 12 for the valve body 10 are of the same, oppositely inserted into the bore 2 seat bodies 24, 25 formed, the Distance is determined by a spacer ring 26. The dimensions of the spacer ring 26 depend on the desired displacement of the plunger 3 and the diameter of the Ball 10.

The seat bodies 24, 25 are provided with sealing elements 27 opposite the wall the bore 2 and the respective thickening 16, 16 'of the plunger 3 is sealed. In addition, they each have an annular groove 28 and transverse bores 29 for connection on the inside with the connections 7, 8.

In the same way, the spacer ring 26 is provided with bores 30 and optionally a groove 31 is provided. The grooves 28 in connection with the thinned sections 17, 17 'of the valve stem each form a shaft 15 or

21 surrounding annular channel 32 or 32 '. In the same way is around the Valve body 10, an annular channel 33 is provided, the annular channels 32, 32 'depending on Position of the stem 3 alternately connect with the annular channel 33. To the Definition of the seat body 24, 25 and the distance -ring 26 in the bore 2 is provided with a snap ring 34 at one end and a retaining ring at the other end 35, which is pressed by the attached electromagnet 6.

In Fig. 1, the valve stem 3 is in its lower position. This creates the connection between the pressure connection 27 and the consumer connection 9 interrupted, while the consumer connection 9 via the ring channel 33 and the Annular channel 32 and the bore 29 are connected to the return port 8. As FIG. 1 clearly shows, in this case it acts on the pressure connection 7 pending pressure medium both on the pressure surface 18 'of the thickening 16' of the lower Shank 21 as well as on the surface 36 opposite this pressure surface 18 ' of the valve body 10 or the section that is already thickening again here 17 '.

In this way, perfect pressure equalization is guaranteed.

It is easy to understand that when forming a valve According to FIG. 1, a modular extension, as it were, but also a simplification is possible. TheFig. 2 and 3 now give examples of use of compared to FIG. 1 expanded valves, while FIG. 4 is a simplified one Valve represents.

The valves according to Fig.2a to 3d each serve to control a Actuating cylinder 37, the piston 38 of which via the lines 39, 40 on both sides with pressure medium can be acted upon or can be connected to the return.

The valves shown in Fig. 2a to 3d each have a housing 41 two independently of one another by means of the electromagnets 42, 43 against the action a common return spring 44 displaceable valve elements 45, 46. Each Valve element 45, 46 in turn consists of ball 10 as a valve body, as well as the shafts 15, 21 with the thickening 16, 16 'and the thinned section 17, 17 '. According to FIG. 1, the ball 10 surrounds an annular space 33 with formation the seats 11, 12, (Fig. 2a).

In the embodiment according to F1R. 2a to 2d is the pressure line 47 to the annular channel 33, the so-called main chamber, of the left valve element 45 connected, while to the main chamber 33 of the right valve element 46 of the Return 48 is connected. The majority of the dilutions 17, 17 ' formed control chambers 49 50 are each paired with the lines 39, 4Q of the Adjusting cylinder 37 connected. The two outer control chambers 49 are also included the line 39 and the two inner control chambers 50 are connected to the line 40.

With such a connection of the valves to the actuating cylinder 37 and the pressure line 47 and the return 48 result in the four in Fig.2a The valve positions shown to 2d have the following working processes: First position (Fig. 2a ): The 'two electromagnets 42, 43 are de-excited. The valve elements 45, 46 are pressed into its rest position by the return spring 44. In this case the Pressure line 47 via the control chambers 50 of the valve elements 45, 46 and these Line 51 connecting the two chambers to the return line 48, so that practically no i2aft can be exerted on the piston 38 via the line 40. On the other hand, however, the discharge of pressure medium through the line 39 is not possible, because the control chambers 49, which are connected to the line 39 via the line 52 are completed. As a result, the piston is against moving in that direction of arrow 53, for example hydraulically blocked by a force acting on 54.

Second position (Fig.2b): The electromagnet 42 is excited and thereby the valve element 45 pushed to the right. In this case, the pressure medium from the pressure medium connection 47 via the control chamber 49 of the valve 45 and the line 39 flow to the actuating cylinder 37 and the piston 38 in the direction of Move arrow 55 to the right. The return of the pressure medium via the line 40 is made possible by the fact that the control chamber 50 of the valve element 46 is opened is.

Britte position (Fig.2c): The electromagnet 43 is excited, whereby the right valve element 46 is shifted to the left, while the left valve element 45 is held in the rest position by the spring 44. In this case it flows Pressure medium from the pressure connection 47 via the chamber 50 of the left valve element 45, the line 51 and the line 40 to the right chamber of the actuating cylinder 57, whereby the piston 38 is displaced in the direction of arrow 56. The return a Pressure means as he left a ae adjusting cylinder 37 is via line 39, the line 52 and the control chamber 49 of the right valve element 46 to the return 48 possible.

Fourth position (Fig. 2d): Both electromagnets 42, 43 are excited. This results in a position that is essentially the reverse of the first Position according to Fig.2a is. Pressure medium can from the supply line 47 via the control chamber 49 of the left valve element 45, the line 52 and the control chamber 49 of the right Valve element to return 48, so that the pressure medium is not able to exert an influence on the piston 38 via the line 39.

On the other hand, there is a backflow of pressure medium from the right chamber of the actuating cylinder 37 via the line 40 is not possible because the two control chambers 50 of the valve elements 45, 46 are closed. In this way the piston 38 is against a shift in the direction of arrow 57, for example by means of a at 54 attacking external force, secured.

The valve arrangement shown in Fig0 2a to 2d thus offers the Possibility of a piston 38 of an actuating cylinder 37 on the one hand in two opposite ones Directions (55, 56) to move. On the other hand, it is possible to use the piston against displacement by an external force in only one direction (53, 55) while the shift in the opposite direction is possible remain.

In the embodiment according to FIGS. Da to 3d, adjusting cylinders are correct 37 and valve with the adjusting cylinder and valve according to FigO2a to 2d. It however, is one chamber of the actuating cylinder 37 via line 39 with the left valve element 45 associated main chamber 33, the other chamber of the actuating cylinder 37 via a line 40 to the main chamber assigned to the right valve element 46 33 connected. The supply of pressure medium takes place at 58 about the branching line 59 and the two check valves 60 to the control chambers 49 of the two valve parts. The chambers 50 are connected to the return via the line 61 62 connected. This arrangement works as follows: First position (Fig.3a): Both magnets 42, 43 are currentless, so that the valve elements 45, 46 through the Return spring 44 are pressed in the direction of the outer control chambers 49 and fit according to the seat with sealing of the control chambers. In this In this case, no pressure medium can pass through the control chambers 49 from the inlet 58 to the actuating cylinder 37 arrive. On the other hand, there are the chambers arranged on both sides of the piston 38 in the adjusting cylinder 37 via the lines 39, 40, the main chambers 33 and the main chambers Controls chambers 50 and the line 61 connected to the return 62. It can therefore the piston rod 63 easily from the outside in any direction in the actuating cylinder 37 are moved.

Second position (Fig. 3b): Indreser position is only the left electromagnet 42 excited, which the valve element 45 in the direction of the associated chamber 50 pushes and presses against the corresponding seat.

In this case, from the pressure medium inlet 58 via the left non-return valve t0, the left control chamber 49, the assigned to the valve element Main chamber 33 and the line 39 pressure medium in the left chamber of the actuating cylinder 37 arrive, whereby the piston 38 with the piston rod 63 in the direction of the arrow 64 is moved.

The pressure medium located in the right chamber can be via the line 40, the control chamber 50 and the main chamber 33 of the valve element 46 and the Line 61 reach return 62.

Third position (Fig. 3c): This position represents a reversal, as it were the position according to FIG. 3b. The electromagnet 43 is excited during the Electromagnet 42 is not energized, in this case by the influx of pressure medium into the right chamber of the actuating cylinder 37 of the piston 38 with the piston rod 63 moved in the direction of arrow 65 to the left.

Fourth position (Fig. 3d): This position is again roughly one Reversal of the position according to FIG. 3a, namely in that both electromagnets 42, -43 energized and thereby the valve elements 45, 46 inwardly against that of the control chamber 50 adjacent seat are pressed. In this case, pressure medium flows from the Inlet 58 via the two check valves 60, the two control chambers 49 and the lines 39, 40 to both chambers of the actuating cylinder 37. It prevails thereby on both sides of the Piston 38 is subjected to the same pressure. But there one Backflow of the pressure medium through the check valves 60 in the line 59 is excluded is, the piston 38 is hydraulically clamped, as it were, and the piston rod 63 hydraulically locked against displacement in both directions.

2a to 3d show that a Valve excellent for controlling an actuating cylinder and at the same time for it Locking and unlocking is suitable.

Finally, FIG. 4 shows how one designed according to the invention Valve 66, which in this case can be tilted via the lever 67 in the ball joint 68 is and acts via the approach 69 on a plunger 70, is actuated, in a larger control system 71 - which should not be explained in more detail - for use can get.

In this embodiment is in a valve housing 72, which Has bores 73 for forwarding the pressure medium, following one end a bore 73 a blind hole 74 attached, in which a seat body 75 in a Fig.1 corresponding training, a spacer ring 76 and an upper end body 77 housed are. In which Valve 66 is a 2/2-way seat valve. As indicated by arrow 78, the pressure medium flows into the annular space 79 in the area of the valve body 80, while the pressure medium starts from the annular space 79 via a further annular space 81 with bores 82 to the bore 73 of the housing 72 arrives.

In contrast to the exemplary embodiment in FIG In the case of the valve body 80, only one of a thinner 87 and one on the underside Thickening 84 on the existing shaft, with the addition of the transition from the thinning 83. to the thickening 84 and the valve body 80 not gradually according to Figure 1, but suddenly occurs The mode of operation essentially corresponds to that of the valve according to Fig. 1 so that a more detailed explanation is superfluous.

Claims (11)

Patent (protection) claims 1. Valve for hydraulic or pneumatic systems, whose with a Shaft provided valve body axially between a closed position in contact a seat and an open position is adjustable away from the seat, wherein a valve connection on a valve body on one side of the seat surrounding the valve body Ring channel and at least one further valve connection on another, on the the other side of the seat arranged and provided surrounding the shaft annular channel is, characterized in that the shaft (15, 21) on its free, the valve body (10, 80) an end facing the valve body with the one surrounding the stem -ifl2. (28, 32, 32, 49, 50) flow-connected pressure surface (18, 18 ') having. 2. Valve according to claim 1, characterized in that the valve switch (15, 21) to form the pressure surface (18, 18 ') on which the valve body (10, 80) has remote end amine thickening (16, 16 ', 84). 3. Valve according to claim 1 and 2, characterized in that the Yentil shaft (15, 21) with a gradual increase in diameter in the thickening (16, 16 ') passes over. 4. Valve according to claim 1 to 3, characterized in that the Valve stem (15, 21) adjoining the valve body (10) to generate a gradual transition is also thickened. 5. Valve according to one or more of the preceding claims, characterized characterized in that a bolt (14) is arranged on the valve body (10, 80), on which one forms at least the thickened part (16, 16 ', 84) of the shaft Sleeve (22) is attached. 6. Valve according to one or more of the preceding claims, characterized characterized in that a ball is used as the valve body (10, 80). 7. Valve according to claim 5 and 6, characterized in that the Bolt (14) is fastened in a bore (13) of the ball (10). 8. Valve according to one or more of the preceding claims, characterized characterized in that the valve body (10) has two axially opposite seat surfaces (11, 12) cooperates and two opposite, each one pressure surface (18, 18 ') has shafts (15, 21), each of which has an annular channel (28, 32, 32', 49, 50, 81) is assigned. 9. Valve according to claim 8, characterized in that in a housing (41) two independently movable valve elements (45, 46) made of a valve body (10) us two opposite shafts (15, 21) including the associated ring channels (49, 50) are arranged. 10. Valve according to claim 9, characterized in that the valve elements (45, 46) are arranged approximately coaxially at a distance from one another. 11. Valve according to claim 9 and 10, characterized in that between the valve elements (45, 46) a return spring acting on both elements (44) is provided. L e r s e i t e