EP2761189A1

EP2761189A1 - Valve device

Info

Publication number: EP2761189A1
Application number: EP12768728.3A
Authority: EP
Inventors: Bertil Lundgren
Original assignee: Nordhydraulic AB
Current assignee: Nordhydraulic AB
Priority date: 2011-09-28
Filing date: 2012-09-28
Publication date: 2014-08-06
Anticipated expiration: 2032-09-28
Also published as: DK2761189T3; SE1150891A1; SE535987C2; EP2761189B1; WO2013045113A1

Abstract

The invention relates to a valve device for mounting on a hydraulic cylinder having a first cylinder port, wherein the valve device has a first cylinder port connection (A') for the connection to the first cylinder port on the hydraulic cylinder, wherein the first cylinder port connection (A') is arranged such that it is optionally connected via a directional valve (22, 36) to a first pressure connection (P1) on the pressure side of the hydraulic pump or to a first tank connection (T1) to a tank. The valve device has a first cylindrical opening (21A) for enclosing a cylindrical connecting element (15), which has a first radial fluid opening (18) which is connected to the first cylinder port, wherein the cylindrical opening (21A) contains the first cylinder port connection (A') on the inside and wherein two seals (28, 30) are arranged such that they seal off the first radial fluid opening (18) so tightly on both sides that a tight connection is produced between the first cylinder port connection (A') and the first radial fluid opening (18) when the connecting element (15) is inserted into the first cylindrical opening (21A).

Description

valve means

TECHNICAL PART

The invention relates to a cylinder-mounted hydraulic

Valve device and a preferably double-acting

Hydraulic cylinder for connection to such a valve device. In particular, the invention relates to a cylinder side mounted

Hydraulic valve device for use in mobile

Hydraulic systems. Mobile hydraulic systems are used, for example, to control mobile machines such as truck-mounted cranes and excavators.

BACKGROUND

In mobile hydraulic systems, in many cases

Safety regulations are adhered to. In so-called truck cranes, excavators and many other types of hydraulically controlled mobile machines, e.g. the lifting function must be hull-proof. A hose break-proof function is obtained when one

Hose break valve attaches directly to the hydraulic cylinder. In "remote-controlled" valve devices, there is the alternative that the valve device is also attached directly to the hydraulic cylinder. Hydraulic valve devices are used to control the

Flow direction and the flow rate to a hydraulic or working cylinder to regulate, which in turn controls the position of the load. Traditionally, the valves are directly, i. mechanically controlled. Today, most valve devices are remotely controlled. The driver or operator controls the valve so far no longer mechanically by means of a lever device, but he uses for the mentioned remote control an electric or hydraulic joystick, which in turn controls magnetic coils or solenoids that regulate the fluid (hydraulic oil) in the valve means. The valve device itself need not be in the vicinity of the driver or operator, but it can be attached to a better location on the machine. If hose burst safety is required, the best position for the valve may be directly on the hydraulic cylinder, in a so-called distributed valve system. A distributed valve system can also lead to a simplification of the hydraulic piping system and a considerable reduction in the number of lines and connections, etc. However, the problem often is that the attachment of the valve to the cylinder is costly and that the space available for mounting the valve on the cylinder is very limited.

In Fig. 1 a and 1 b is shown how a valve device 4 is mounted in a conventional manner directly on a hydraulic cylinder 1. On the hydraulic cylinder 1 is a connection block 2, which is welded in this case to the cylinder 1. The terminal block 2 includes a mounting side 3 with drilled channels A 'and B' for the two ports of the cylinder 1 and screw holes 5a for attaching a valve device. The cylinder port A, the piston side of the

Hydraulic cylinder 1 has, is mounted below the terminal block 2 and not visible in the picture. Instead, however, a connecting line 6 can be seen, which leads from the terminal block 2 to the Zylinderpforte B, which opens on the piston rod side of the hydraulic cylinder Ί.

In picture! b is the terminal block 2 with a on the

Attachment side 3 attached valve device 4 shown. It also shows the connection ports of the directional valve to tank T and pump P. Because of the high hydraulic pressure, which can typically be up to 40 MPa, very large pressure forces between valve 4 and port block 2 can arise. The valve 4 must therefore be fastened with several large bolts 5b, which in the for

provided holes 5a are mounted in the terminal block 2. This connection causes both the valve 4 and the

Terminal block 2 are relatively large and bulky. In addition, the attachment with several stable bolts in the worst case can lead to deformations in the housing of the valve 4, due to the

extremely small clearance between the valve spool and the valve housing may cause changes to the slide, which jeopardize the functioning of the valve and the safety of the machine.

There is therefore a need for a better connection for a cylinder-side mounted valve, which allows a better functioning than the previously known cylinder-side mounted valves.

SUMMARY OF THE INVENTION

An object of the invention is to provide a new type of cylinder-side mountable hydraulic valve device in which the technical problems described above do not occur. The invention initially relates to a valve device for mounting on a hydraulic cylinder, which is provided with a first Zylinderpforte. The valve device includes a first Zylinderpfortenanschluss for connection to the first cylinder port on the hydraulic cylinder, and the first Zylinderpfortenanschluss is arranged so that via an adjustable directional valve can be connected to a first pressure port on the pressure side of a hydraulic pump or to a first tank connection to a tank , The valve device further comprises a first cylindrical opening for enclosing a cylindrical connection element with a first radial fluid port connected to the first cylinder port, the cylindrical port containing the first cylinder port port internally, and two seals mounted to receive the first port Close radial fluid port on both sides so tightly that a tight connection between the first Zyl inderpfortenanschluss and the first radial fluid port is formed when the connection element is inserted into the first cylindrical opening.

Furthermore, the invention relates to a hydraulic cylinder, which includes a first cylinder port for connection to a mounted on the hydraulic cylinder valve device according to the above-mentioned embodiments. The hydraulic cylinder further includes a connection tube fixedly connected at its first end to the first cylinder port and having a connection element with at least one radial hole which leads into a part of the connecting element of the hydraulic cylinder, which leads to the first end of the tube and wherein the Radial hole at one

Enclosure element is to be connected in the valve device, the inside a Zylinderpfortenanschluss for an enclosing

Contains connection to the radial holes of the connection element. The invention provides a valve device with a considerably improved connection, in particular to a double-acting hydraulic cylinder. Characterized in that the valve means enclosing the connection pipe, the forces are enclosed by the pressure of the hydraulic fluid in the valve housing and the technical problem of the occurrence of a damaged valve spool is completely excluded. In addition, the mounting of the valve device according to the invention allows a considerable space saving, since no special fasteners such as bolts or the like are needed. Another advantage is that the wiring can be considerably simplified due to the valve device according to the invention, because fewer hoses are required and the hoses can also be routed along the hydraulic cylinders along, which significantly reduces the required length of the hoses.

From the independent claims and the detailed

Description of the invention will show the advantageous embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, the invention will be described in detail, reference being made to the attached drawings, of which:

Fig. 1a shows a conventional hydraulic cylinder with a mounting side for mounting a conventional directional valve; Fig. 1 b a conventional hydraulic cylinder with a mounted

usual Richtu gsventil shows; Fig. 2 shows a hydraulic cylinder according to an embodiment of

Invention with a connection pipe for connection to a valve device shows;

Fig. 3 shows the hydraulic cylinder in Fig. 2 with a valve device according to an embodiment of the invention in a

Connecting direction with the connecting pipe shows;

Fig. 4 shows a section of the valve device according to the invention in

Fig. 3 shows when this has been plugged onto the connecting pipe of the hydraulic cylinder; Fig. 5 shows the hydraulic cylinder in Fig. 3, in which the

Valve device according to the invention has been plugged onto the connecting pipe and has been further connected to the piston rod side;

Fig. 6 shows an excavator arm with three cylinder devices mounted on the cylinder side according to the invention;

Fig. 7 shows a hydraulic cylinder with a connection pipe to which a load-holding valve is connected according to a further embodiment of the invention; and

Fig. 8 shows in the manner of a hydraulic circuit diagram a connection diagram for the load-holding valve according to the further embodiment.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 2 shows a hydraulic cylinder 1 according to the invention with a connection pipe 10 for connection to a valve device according to the invention. The connection pipe 10 has a first end 1 1, which fixed to a first cylinder port A on the piston side of Hydraulic cylinder 1 is connected. A free second opposite end 12 of the connection pipe 10 includes a connection element 12a, which is connected to another cylinder port B on the piston rod side of the

Hydraulic cylinder 1 to be connected. A bracket 13 is located at a certain distance d from the second end 12 of the

Connecting pipe 10 to hold the connecting pipe 10 on the hydraulic cylinder 1, but also to secure the connection to a valve device 20, s. Fig. 3.

The portion of the connecting pipe 10, which is located between the bracket 13 and the free second end 12 of the tube, consists of a

Terminal element 15. As shown in FIG. 3, the length d of the terminal element 1 corresponds to 5, i.e., 5. of the element between the second end 12 of the connection pipe 10 and the holder 13, the length d of a

Enclosing portion 21 of the valve device 20. The

Enclosing portion 21 includes a continuous cylindrical opening 21 A and 21 B, of the connecting element 1 5 of the

Connection pipe 10 is to be penetrated. If the valve device 20 has been connected in this way to the hydraulic cylinder 1, it can be attached to the bracket 1 3 with a fastening device.

In Fig. 5, the valve device 20 is in place on the

Connecting pipe 10 and with an attached piston rod line 16 to the connection part 12a of the free second end 1 2 shown. The

Piston rod line 16 connects the valve device 20 with the

Piston rod side of the hydraulic cylinder 1. The connection between the piston rod line 16 and the free second end 1 2 of the

Connecting pipe 10 is preferably arranged so that the Valve device 20 in relation to the connecting pipe 10 and thus also to the hydraulic cylinder 1 can be attached and that the

Piston rod line 16 can be connected to the connecting pipe 10. In this way, a tight and secure connection between the valve means 20 and the port ports of the two chambers of the hydraulic cylinder 1, i. the first cylinder port A on the piston side of the hydraulic cylinder 1 and the second cylinder port B on the piston rod side of the hydraulic cylinder 1. The connection part 12a of the free end 12 has a diameter which is smaller or at most as large as the inner diameter of the continuous cylindrical opening, the consists of the individual, but continuously connected openings 21 A and 21 B. This diameter ratio is a prerequisite that the connection part 12a can also be passed through the openings 21A and 21B.

The valve device 20 also includes connections to a

Pressure supply device, such as a pump P and a tank T and other connections for a possible further connection with other valve devices. Thus, valve device 20 contains a first tank connection port T1 for connection to a tank T and a first pump connection port PI for connection to a pump P. In addition, the valve device 20 is provided with a second tank connection port T2 for a possible further connection to a tank connection port of a further valve device and a second

Pump port P2 provided for a possible further connection to a pump port on the same valve device.

If the second tank port T2 and the other

Pump port P2 are used, the valve device 20 also serves as a passage for the tank or pump connection to the other valve devices. If the second tank connection port T2 and the other pump port P2 are not used, they should be closed again by usual means. For the sake of clarity, the valve device 20 is shown in FIGS. 3-5 without connected hoses for pumps and tank lines.

In Fig. 4 the valve means is shown partly in cross section and partly in a sectional view. As is apparent from Fig. 4, the valve means 20 includes a continuous cylindrical opening 21 A and 21 b for enclosing the connecting element 1 5 of the connecting pipe 10, which is arranged so that it is the hydraulic fluid partly to the first cylinder port A and partly to the second Zylinderpforte B leads. However, it is also possible in the context of the invention that the valve device 20 instead contains two separate openings 21 A and 21 B. An opening 21 A, left in the figure, with the first

Zylinderpfortenanschluss A 'and an opening 21 B, right in the

Figure, with the second Zylinderpfortenanschluss B '. The

Zylinderpfortenanschlüsse A 'and B' consist in the illustrated

Embodiment of all-round groove-shaped recesses, which are connected via the lines 23 and 24 in conjunction with a directional valve 22 and a corresponding pressure relief valve 27A and 27B.

In the illustrated embodiment, the connecting element 1 5 has the

Connecting pipe 10 a solid middle part, the first

Cylinder port A 'and the second B' effectively separates from each other. The first Zylinderpfortenanschluss A 'is also referred to as the piston connection, because it leads to the first cylinder port A on the piston side of the hydraulic cylinder 1. The second

Zylinderpfortenanschluss B 'is also below Called piston rod connection because it leads to the second Zylinderpforte B on the piston rod side of the hydraulic cylinder 1.

The connecting pipe 10 includes the radial openings 18 and 19 for

Connection of piston port A 'and piston rod port B' with the directional valve 22, which is e.g. consists of a valve spool and the fluid (oil) via 4 connections or the lines 23-26 controls, all of which are connected at one end to the directional valve 22 fluidly. The second end of the first conduit 23 is connected to the piston port A 'and the second conduit 24 to the piston rod port B'. The third line 25 is connected to the pump P via the first tank connection port T1 to the tank T and the fourth line 26 via the first pump connection port P1.

The position of the directional valve 22 is controlled remotely in the illustrated embodiment electrically via a first solenoid S1. A second solenoid S2 is for controlling a pressure regulator in the Venti leinrichtung 20 mounted on a not shown here, but known to those skilled in the art. The invention is not limited to a specific control mode, but it is also suitable for use in mechanically controlled valves.

The directional valve 22 shown in Fig. 4 is by means of said first solenoid Sl slidably actuated to the left and right. In Fig. 4 it is shown in the closed position 22c, in which no fluid flows through. When the directional valve 22 is shifted leftward to a first open position 22a, the first pump port PI is attached to the first pump port

Piston port A 'via the fourth and first line 26 and 23 and connected via the radial openings 18. At the same time there will be a reflux of Piston rod connection B 'to the first Tankanschl usspforte T1 via the radial openings 19 and the second and third line 24 and 25 passed. Instead, when the directional valve 22 is shifted to the right, the first pump port P1 is communicated to the piston rod port B 'via the fourth and second conduits 26 and 24, respectively

Radial openings 1 9 connected. At the same time, a fluid flow from piston connection A 'to the first Tahkanschlusspforte T1 via the

Radial openings 18 and the first and third line 23 and 25 go.

In addition, two known per se in the figures.

Pressure relief valves 27A and 27B shown as

Overload protection serve and the piston connection A 'and the

Connect the piston port B 'to the tank port T1 if the pressure in the port in question exceeds a certain predetermined value.

The valve device 20 preferably also includes three seals 28, 29 and 30 which are mounted around the cylindrical connection element 1 5 around. A first seal 28 is mounted so as to seal the connection between the first cylindrical opening 21 A and the cylindrical connection element 1 5 to

to ensure that no fluid can enter the first opening 21A. A second seal 29 is mounted so as to close the connection between the second cylindrical opening 21 B and the cylindrical connection element 1 5 tightly to ensure that no liquid can penetrate into the second opening 21 b. A third intermediate gasket 30 is mounted to separate the separate spaces surrounding the fluid ports 18 and 19 when the corresponding valve lines 23 and 24 are in place Zylinderpfortenanschlüsse Α 'or B' are connected to

Make sure the liquid is not between the

Cylinder port connections can penetrate.

The seals may e.g. consist of usual O-rings. Alternatively, it is possible that the openings 21 A and 21 B are provided with a seal for the cylindrical connection element 1 5, which consists of a customized, sufficiently tight-fitting sealing element and does not pass hydraulic fluid. The person skilled in the art knows other suitable methods for a seal between a pipe and an inner rod, and the invention is not limited to any of these known seals. But some kind of seal is needed.

In the illustrated embodiment of the valve device 20, the first and the second tank connection ports T1 and T2 are mounted on the opposite sides of the valve device 20. Likewise, the first and second Pumpenanschlusspforte P1 and P2 are on the

attached to opposite sides of the valve device 20. All these connection ports are arranged so that they are substantially parallel to each other, so that the first tank or pump line T1, P1 parallel to the hydraulic cylinder 1 on one side of the valve device 20 and the second tank or pump line T2, P2 paral to the

Hydraulic cylinder 1 are connected to the other side of the valve device 20.

FIG. 6 shows a crane boom 40 with a crane arm 41 and a crane bucket 42. The boom 40 can be raised and lowered by means of a first hydraulic cylinder 1, on which a first valve device 20 is mounted, which controls the relative movements of the piston rod 6 in FIG To control relationship to the piston. A first pair of conduits with a hose from the tank of the vehicle (not shown) and a hose from the pump are connected to the first valve means 20. As described above, the valve device 20 is also connected via a connecting pipe 10 to the first cylinder port A on the piston side of the hydraulic cylinder 1 and via a piston rod line 16 to the second cylinder port B on the piston rod side of the hydraulic cylinder 1.

Coming from the first valve device 20, a second line pair 44 is connected to a second valve device 20 ', which controls the angle between boom 40 and crane arm 41 by means of a second hydraulic cylinder 1'. In addition, a third line pair 45 coming from the second valve device 20 'is connected to a third valve device 20 "which controls the predeterminable angle of the crane bucket 42. The first and second valve devices 20 and 20' both act as feedthroughs, while the third valve device 20 "uses only the inputs (T1 and P1) for the pump and tank lines, the outputs (T2 and P2) remaining unused and preferably reclosed.

From Fig. 6 shows one of the advantages of the invention: the

Wiring to and from the valves is much easier, partly because the lines from one valve device to another can go on and partly because the lines beyond parallel to the hydraulic cylinders, from terminal to terminal, can be attached, so that the route as possible becomes short.

FIGS. 7 and 8 show another embodiment of a valve device 35 according to the invention. This valve device 35 is as a Load-holding valve, which differs from that described above

Valve device 20 differs primarily in that it contains no directional valve and that instead it has a pressure-regulated valve 37 and a check valve 38. It can be seen from the diagram in FIG. 8 that a separate directional valve 36 is connected to the valve device 35. If the directional valve 36 is actuated to the left, the hydraulic fluid from pump P flows through the check valve 38 and into the chamber on the piston side of the hydraulic cylinder 1 through the first cylinder port A. The pressure-regulated valve 37 remains normally closed in this position. When the piston rod is pushed up, the hydraulic fluid from the piston rod side of the

Cylinder pushed out through the second Zylinderpforte B. The

Hydraulic fluid exiting the piston rod side of the cylinder is directed to tank T through the directional valve 36.

When the directional valve 36 is instead operated to the right or shifted, the pressure side PI is connected to the other Zylinderpforte B and the first cylinder port A is connected to tank T at the same time. Since no fluid flows in this direction through the check valve 38, SA and SB must jointly exceed the spring force of the spring 39 so that the pressure-regulated valve 37 into the next open position and the hydraulic fluid can leave the piston side of the cylinder through the first cylinder port A.

It is thus clear to a person skilled in the art that the

Valve means 35 with respect to the connection corresponds to a conventional load-holding valve. What is new is how it is connected to the hydraulic cylinder 1. This is shown schematically in FIG. 7 and corresponds the way in which the above-described valve device 20 to the

Hydraulic cylinder 1 is connected.

The valve device 35 thus in turn includes a through opening 21 a-21 b, through which a connecting pipe 10 is inserted. The connecting pipe 10 is at its first end 1 1 fixed to the first

Zylinderpforte A connected to the hydraulic cylinder 1. The

Connecting pipe 10 further has a connection element 15 with at least one radial hole 18. The connection element is integrated in FIG. 7 in the valve device 35 and thus can not be seen. However, the connection to the separate parts 15A and 15B of the connection pipe 10 may preferably have substantially the same configuration as in the above

described valve device 20, which is shown in Fig. 4. The difference is therefore that the valve device 35 in the form of a load-holding valve contains no directional valve. Instead, the valve means 35 includes a pressure-regulated valve 37 and a

Check valve 38 in the manner shown in FIG. 8.

From this other embodiment of the valve device also shows that the connections are designed differently to the valve device 35. Instead of being connected directly to pump P and tank T via a pump or tank connection port, the valve device 35 is connected to an external directional valve 36. That is why the

Valve means 35, a first relay connection A ", via the pressure-regulated valve 37 and the check valve 38 to the first

Zylinderpforte A is connected, and a second relay B "connected to the second Zylinderpforte B eventuel l via a not-shown pressure-regulated valve or a check valve, comparable as already explained for the cylinder port A. The load-holding valve should ensure that the hydraulic cylinder does not retract uncontrollably in the event of a hose breakage. Nevertheless, if the hose connection between the first relay A "and the external directional valve 36 fails, it is possible to control the lowering or retraction of the hydraulic cylinder If the pressure on the piston side of the hydraulic cylinder is sufficient to allow the signal pressure SA from the first cylinder port A If the spring force of the spring 39 alone exceeds that, then the pressure regulated valve 37 enters a partially open position so that the hydraulic fluid can leave the piston side of the cylinder in a controlled manner through the first cylinder port A. If the pressure is insufficient, the pump P must be sufficient provide great pressure, thus the signal pressure SA from the first

Zylinderpforte A and the signal pressure SB of the second Zylinderpforte B together exceed the spring force of the spring 39 and the pressure-regulated valve 37 opens. The greater the pressure mediated by the pump, the greater the signal pressure SB from the second cylinder port B and the more the pressure-regulated valve 37 is opened. thanks to the

Load holding valve 35, it is thus possible to control the lowering of the hydraulic cylinder 1 by operation of the external directional valve 36.

Both embodiments of the valve devices 20 and 35 can be used for both single-acting and double-acting hydraulic cylinders. When used for single-acting hydraulic cylinders, they preferably have only one cylindrical opening 21A into which one end of a connection pipe is inserted.

Thus, if they are double-acting, they also have a continuity connection to the second cylinder port B. A load-holding valve may also be configured to have a pressure-regulated valve and a check valve for both Zylinderpforten A and B has. This is important in applications where the load can act on both sides relative to the hydraulic cylinder.

The connection pipe has radial holes for connection to the first one

Cylinder Door A. An advantage of the radial holes (18 and 19) is that they are not axially mounted at the end of the connection pipe and that the pressure of the hydraulic fluid in this way can not generate forces in the axial direction. The forces are not just inside the

Valve device received, but also by the seals 28, 29 and 30th

In the above description of the invention has been made to various embodiments. However, the invention is not limited to any of these specific embodiments. Instead, it is limited only by the extent of protection, that in the following

Claims is defined.

Claims

P a n t a n s p r e c h e

Valve device (20, 35) for mounting on a

Hydraulic cylinder (1) having a first Zylinderpforte (A), wherein the valve means (20, 35) has a first Zylinderpfortenanschluss (Α ') for connection to the first Zylinderpforte (A) on the

Hydraulic cylinder (1), wherein the first

Zylinderpfortenanschluss (Α ') is arranged so that it via a directional valve (22, 36) optionally to a first pressure port (P1) on the pressure side (P) of a pressure supply device, such as a hydraulic pump, or to a first tank port (T1) to a Tank (T) is connected, characterized in that the valve means (20, 35) has a first cylindrical opening (21 A) for enclosing a cylindrical

Includes connecting element (15) having a first radial fluid port (18) which is connected to the first cylinder port (A), that the cylindrical opening (21 A) inside the first

Cylinder port connection (Α ') contains and that at least two seals (28, 30) are arranged so that they close on both sides of the first radial fluid port (18), so that a tight connection between the first Zylinderpfortenanschluss (Α') and first radial fluid opening (18) is formed when the connection element (15) in the first cylindrical opening (21 A) is inserted.

Second valve means (20, 35) according to claim 1, characterized

characterized in that it comprises a second cylindrical opening (21 B) for enclosing a cylindrical connecting element (1 5), which is arranged so that it to a second Cylinder gate (B) on the hydraulic cylinder (1) that the opening (21 B) inside a second Zylinderpfortenanschluss (Β ') contains, that the cylindrical connection element (15) has a second radial fluid port (19) with the second Zylinderpforte (19 B) is connected and that at least two seals (29, 30) are arranged so that they close the second radial fluid opening (19) on both sides, so that a tight connection between the second Zylinderpfortenanschluss (Α ') and the second radial Fluid opening (19) is formed when the

Connecting element (1 5) in the second cylindrical opening (21 B) is inserted.

Valve device (20, 35) according to claim 2, characterized in that it comprises a continuous cylindrical opening (21 A, 21 B) for an enclosing connection to a cylindrical connecting element (1 5), that the

cylindrical connection element (15) has a stable central part (1 7) which divides the connection element (15) into two separate parts (1 5A, 15B), of which a first part (1 5A) of the cylindrical element (1 5) first cylinder port (A) and a second part (15 B) to the second cylinder port (B) leads and that both separate parts radial fluid openings (18, 19), via which the respective Zylinderpforten (A, B) to the

corresponding Zylinderpfortenanschlüsse (Α ', Β') are connected.

Valve device (20, 35) according to claim 3, characterized in that the second part (15B) of the cylindrical connection element (1 5) contains a connection part (12a) which surrounds the end (12) of the cylindrical connection element (1 5). forms and that the connecting part (12 a) is arranged so that it from the second cylindrical opening (21 B) protrudes to be connected to the second cylinder port (B).

Valve device (20, 35) according to claim 3 or 4, characterized in that it comprises three seals (28, 29, 30) which are arranged around the cylindrical connecting element (1 5) around a first seal (28) so is arranged to close off the connection between the first cylindrical opening (21 A) and the cylindrical connection element (15) tight, a second seal (29) so that it connects between the second cylindrical opening (21 B) and the cylinder-shaped connecting element (15) tightly closes, and a third, intermediate seal (30) so that it separates the separate spaces in which the respective cylinder ports (A, B) to the corresponding Zylinderpfortenanschlüsse (Α ', Β') are connected ,

Valve device (35) according to one of the preceding

Claims, characterized in that the

Valve means (35) is a load-holding valve having a pressure-regulated valve and a check valve to hold the load in case of a hose break at the first cylinder port (A) on the hydraulic cylinder (1), and in that the valve means (35) to a separate directional valve (36) for optional connection to the first pressure port (PI) or the first tank port (T1).

Valve device (20) according to one of claims 1 to 5, characterized in that it comprises a directional valve (22) which can be adjusted between a closed position (22c) and two open positions (22a, 22b)

Directional valve in the first open position (22a) the first Pressure port (PI) with the first Zylinderpfortenanschluss (Α ') and the first tank connection (T1) with the second

Zylinderpfortenanschluss (Β ') connects and wherein the

Directional valve (22) in the second open position (22b) the first pressure port (PI) with the second Zylinderpfortenanschluss (Β ') and the first tank port (T1) with the first

Cylinder port connection (Α ') connects.

8. Valve device (20, 35) according to claim 7, characterized

in that it has a second tank connection port (T2) for a possible connection to a tank connection port of a further valve device (1 ', 1 ") and a second

Pump port (P2) for connection to the same further valve device (V, 1 ").

9. valve device (20, 35) according to claim 8, characterized

characterized in that the first and second tank ports (T1, T2) are mounted on opposite sides of the valve means (20, 35) and that all of these ports are substantially parallel to each other so that conduits connected thereto are parallel to each other

extending from opposite sides of the valve device (1).

10. Hydraulic cylinder (1) with a first cylinder port (A) for connection to a mounted on the hydraulic cylinder

Valve device (20, 35) according to one of the preceding

Claims, characterized in that the

Hydraulic cylinder (1) has a connecting tube (10) which is connected at its first end (1 1) fixed to the first Zylinderpforte (A), and a connecting element (1 5) having at least one radial hole (18), in a part (1 5a) of the

, Connecting element (1 5) of the hydraulic cylinder, which part (15A) leads to the first end (1 1) of the tube (10) that the radial hole (18) to a Umschließungselement (21) in the valve means (20, 35) are connected ought to do that in one

Cylinder port connection (Α ') for an enclosing connection to the radial hole (18) of the connection element (1 5) contains.

1 1. Hydraulic cylinder (1) according to claim 10, characterized

characterized in that the hydraulic cylinder (1) a

double-acting hydraulic cylinder, which also has a second cylinder port (B) for connection to the same valve means (20, 35) that the connecting element (1 5) of the connecting pipe (10) has separate radial holes (18, 19), which in separate parts (15A, 15B) of the connecting element (15) of the hydraulic cylinder (1), which parts (1 5A, 15B) by a stable central part (1 7) are separated from each other, that a first part (1 5A) of the two separate parts to the first end (1 1) of the tube (10) leads and a second part (15 B) to the second end (12) of the tube (10) leads to the further connection to the second Zylinderpforte (B), and that the radial holes (18 , 19) are to be connected to an enclosing element (21) in the valve device (20), the inside two Zylinderpfortenanschlüsse (Α ', Β') for a preferably

enclosing connection to the corresponding radial holes (18, 19) of the connection element contains.

12. Double-acting hydraulic cylinder (1) according to claim 1 1, characterized in that the second end (12) of the

Connecting pipe (10) includes a connecting part (12a) which protrudes from the enclosing element (21) of the valve device (20) and is connected to the second cylinder port (B) that the connecting part (12a) has a diameter which is smaller or at most as large as the inner diameter of the continuous cylindrical opening (21 A, 21 B) is.