JP2002527296A - Fluid driven actuator - Google Patents

Abstract

SUMMARY The present invention relates to a fluid driven actuator including a housing (2) and a piston rod (6) that can be moved relative to the housing (2) by fluid energy. At least one control valve (38, 38 ') that can be activated in response to the position of the piston rod (6) includes a control element. The control element controls the fluid connection between the two fluid spaces (46 and 47) in cooperation with a sealing part (43 and 43 ') fixed to the housing. The control element is constituted directly by a piston rod (6) whose outer peripheral surface is correspondingly shaped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] The present invention is a fluid-driven actuator including a housing, a piston rod movable relative to the housing by fluid energy, and at least one control valve operable in accordance with the position of the piston rod. The valve includes a control member for controlling a fluid connection in the two fluid spaces in cooperation with the sealing portion, wherein the sealing portion is fixed to the housing.
The present invention relates to a fluid-driven actuator.

[0002] Such a fluid-driven actuator known to the applicant is designed in the form of a pressure booster, whereby the pressure of the fluid is increased. In this case, the housing has two piston chambers in which the pistons connected by piston rods are provided to form a functional working unit. The piston chambers are each divided into two working spaces with the aid of a valve device, the valve means serving to make it possible to control the outer working space so that a reciprocating movement of the functional working unit takes place. I have. The fluid pushed out of the working space on the piston rod side during the reciprocating movement is supplied to the high-pressure space where the increased pressure is accumulated. A control integral with the housing, wherein a control member extends into the adjacent working space on the piston rod side for switching the valve means and is mechanically actuated towards the end of the stroke by the impact of the piston. It is possible to provide a valve.

[0003] A disadvantage of such a configuration is that the means for operating the control valve is unreliable and wears easily. Therefore, it has already been proposed to use an electrical signal to switch the function of the valve, this signal being generated by a sensor which responds to the piston without physical contact. However, this has the disadvantage that for control and energy purposes it results in a relatively expensive arrangement that must be operated with electrical energy.

[0004] It is therefore an object of the present invention to provide a fluid-driven actuator with an economical construction, which is less prone to wear, but which is nevertheless highly functionally reliable with respect to valve actuation. To this end, according to the invention, the control member of the control valve is directly constituted by a correspondingly formed shape of the outer circumference of the piston rod.

Thus, it is no longer necessary to provide each control valve with a separate control member which is to be actuated by a mechanical connection which is subject to wear. The control member is constituted directly by a piston rod which controls the fluid connection in the fluid space in cooperation with the sealing part, since the outer periphery is appropriately shaped. All that is required to completely shut off the fluid connection is to provide an external shape that makes liquid tight contact with the seal. If the fluid connection is to be released, it is only necessary to correspondingly reduce the cross-section of the external shape of the piston rod, so that between the piston rod and the sealing part a transfer gap allowing the transfer of the hydraulic medium Occurs. By selecting the position and length of the longitudinal section having the corresponding shape of the piston rod, the actuation of the control valve by stroke can be facilitated, so that any valve means can operate as well. it can. As a result, in a preferred application relating to a pressure booster, the function of the valve means, which serves to pre-adjust the direction of the stroke, can be switched over simply and without using wear-out mechanisms. If desired, one or more mass-produced valves can be combined to make the valve means, which may be external to the housing. It is also possible to provide a space saving configuration with integrated valve means in the housing, in which case the valve may be usefully designed as a multi-way pulse valve. Furthermore, expensive sensors, additional actuation elements (such as permanent magnets) and additional control system elements can be dispensed with.

[0006] Further useful developments of the invention are defined in the dependent claims. In a preferred configuration, the two fluid spaces on both sides are axially adjacent to the sealing part surrounding the piston rod, the piston rod having at least one longitudinal part which serves to block the fluid connection (such a part being sealed) The vertical portion is in close contact with the sealing portion when it takes a position overlapping the sealing portion, that is, when it is usually at the same position in the axial direction as the sealing portion, and thus is in a closed or sealed state. It has such a shape. Furthermore, the piston rod preferably has at least one longitudinal part (referred to herein as a transmission part), which assumes a position covering the sealing part, ie at least essentially A moving air gap is created that, when aligned with the sealing portion, connects the two fluid spaces, the air gap allowing a fluid flow for the hydraulic medium to pass.

At the same time, it is possible to simplify the production while enabling a high flow rate, provided that the transmitting portion is constituted by a groove-shaped recess extending on the outer peripheral surface of the piston rod. It should further be noted that, depending on the desired control function, the desired number of transmissions may be provided on the piston rod at a suitable axial distance from each other.

[0008] The piston rod is preferably connected to at least one piston separating the two working spaces in the piston housing, the first of the spaces to be controlled with respect to the connection being: It is connected to or formed by the working space on the piston rod side.

More particularly, if the fluid-driven actuator is configured in the form of a pressure booster, it is desirable to have one valve means adapted to be activated by at least one control valve. . Through the valve means, it is possible to preset the direction of the stroke of the piston rod. Thus, for example, the direction of the stroke can be reversed by a method corresponding to a predetermined axial position of the piston rod.

[0010] The sealing part of the control valve is preferably located in the wall of the housing through which the piston rod extends, particularly preferably by means of an annular seal in the form of a lip seal or a so-called groove ring. Is drawn. In one configuration of the device in the form of a pressure booster having two piston chambers, the pistons are connected by a piston rod to form a functional working unit, and a partition provided between the piston chambers is necessary. If any, the direction of the stroke is preset when the inside of the duct extending from the valve means to the working space outside the piston chamber is simultaneously in the no-pressure state or at the same time at the specified operating pressure (primary pressure). A logic control device for reversing the valve means to be operated may be accommodated. The present invention is described in detail below with reference to the accompanying drawings.

The invention is described with reference to a fluid-driven actuator 1 in the form of a pressure booster. However, it should be pointed out that the invention can be applied with respect to other types of fluid-driven actuators. The actuating device 1 according to the present example includes a housing 2 in which two piston chambers 4 and 4 ′ arranged in the axial direction and separated from each other by an intermediate wall 3 are formed. Each chamber is provided with an axially moving piston 5 and 5 ', and each piston chamber 4 and 4'
In close contact with the surface of the cylindrical hole.

The two pistons 5 and 5 ′ are fixed to one another by a piston rod 6 extending axially through the intermediate wall 3 so as to constitute a functional working unit which can be moved axially together. Are linked together. The intermediate wall 3 has an axially oriented passage hole 8 through which the piston rod 6 extends.

Each piston 5 and 5 ′ has an associated piston chamber 4 and 4 ′ with an inner working space 12 and 12 ′ on the piston rod side and connected to the intermediate wall 3, and a piston rod extending into it. Not axially facing outer working spaces 13 and 13
'And is divided into.

A first primary duct device 14, which extends at least partially inside the wall of the housing 2, is provided with an intermediate valve means 15 used for being actuated by fluid energy.
Through the two outer working spaces 13 and 13 ′ are provided on the outer surface of the housing and are connected to a supply port 16 to which a fluid, more particularly compressed air under pressure P 1, is supplied. I have. As part of the first primary duct device 14, there is more conveniently an intermediate pressure setting device 17 as shown diagrammatically in FIG. 2, which pressure setting device preferably takes the form of a pressure regulating device. ing. This device is arranged close to the supply port 16 and before the valve means 15 and provides for the possible setting of the appropriate primary pressure to be established in the valve means 15. If necessary, the pressure setting means 17 can be omitted.

The valve means 15 of the present embodiment relates to a so-called pulse valve.
It is configured in the form of a 5/2 valve, which can be switched by a short-time fluid operation, and retains each switching position even after the operating pressure stops. The first primary duct device 14 is connected by valve means 15 to one or more duct sections 18 following the supply port and to at least two duct sections 19 on the piston space side opening into two outer working spaces 13 and 13 '. It is further divided. Further, the valve means 15 is in communication with the two ventilation ducts 20. Depending on the switching position of the valve member 23 of the valve means 15 shown diagrammatically in FIG. 1, the fluid under primary pressure is thus supplied to the outer working spaces 13 and 13 'respectively, while at the same time The other outer working spaces 13 and 13 'are respectively ventilated. Thereby, the functional working unit 7 is moved to one side or the other along the axial direction.

The switching of the valve means 15 is effected by a fluid under operating pressure acting on an actuating means 24 cooperating with a valve member 23, for example in the form of a servo piston or servo diaphragm. In this embodiment, each actuating means 24 is associated with two axial ends of the valve member 23, and the fluid actuation of the means 24 is triggered via the actuating duct 22. A second primary device 25, also best connected to the supply port 16, is in communication with the two working spaces 12 and 12 'on the piston rod side via first check valves 26 and 26'. . In the embodiment shown, it comprises a common duct 27 starting from the supply port 16 and branching into two branches 28 and 28 'inside the housing wall, the branches being located on the piston rod side. Opening toward the working spaces 12 and 12 ', first check valves 26 and 26' are provided therein, respectively. The arrangement of the first check valves 26 and 26 'is such that fluid can flow toward the working spaces 12 and 12' on the piston rod side, and is blocked in the opposite direction.

Furthermore, a secondary duct device 32 is provided, which communicates on the one hand with the working spaces 12 and 12 ′ on the piston rod side and on the other hand on the outer surface of the housing 2 and has a large capacity, The high-pressure receiver 34 communicates with the outlet 33 connected thereto.
In the high-pressure receiver 34, a secondary pressure P2 higher than the secondary pressure P1 applied at the inlet
Occurs.

The secondary duct device 32 is also equivalent to the second primary duct device 25, and this device 32 also has a common duct portion 35 extending from the outlet 33 and a branch from the common duct portion 35 to the piston rod side. Into two branches 36 and 36 'which open to the working spaces 12 and 12'. Each branch 36 and 36 'has a second check valve 37 having a flow direction opposite to that of the first check valve 26 and 26'.
And 37 ', so that fluid flow is possible from the working space 12 and 12' on the piston rod side to the high-pressure receiver 34 and is blocked in the opposite direction.

The check valves 26 and 26 ′ and furthermore 37 and 37 ′ can be provided externally in principle, but are preferably arranged in the intermediate wall or the partition 3. During operation of the actuating device starting with the state shown in FIG. 1, by presetting the desired switching position of the valve means 15, a fluid of primary pressure P1 is supplied to the outer right working space 13 ', while the other The outside working space 13 is evacuated. Thus, the functional working unit 7 moves to the left and the right piston 5 ′ of FIG. 1 moving towards the bulkhead 3 transfers the fluid supplied via the second primary duct device 25 to the associated piston rod side. It compresses into the working space 12 ′ and passes the compressed fluid via a branch 36 ′ of the secondary duct device 32 leading to a high-pressure receiver 34 communicating with the working space 12 ′ on the piston rod side. Let it flow. At this time, the second check valve 37 in the other duct portion 36 prevents the outflow fluid from moving to the other work space 12 on the piston rod side.

During such a stroke movement, the fluid which has been exposed to the primary pressure P 1 via the primary duct device 25 has an increased volume on the piston rod side of the piston chamber 4 located on the left in FIG. Into the working space 12. When the functional unit 7 has reached the end of the stroke, the working space 12 of the piston chamber 4 on the piston rod side—the left side in FIG. 1—is at its maximum volume.
The next step is the switching of the valve means 15 so that the direction of movement of the functional working unit 7 is reversed and the fluid is now in the working space 12 on the piston rod side of the piston chamber 4 on the left side of FIG. And is exposed to the pressure prevailing there and flows through the secondary duct device 32 to the high pressure receiver 34.

Therefore, the secondary pressure P2 is gradually accumulated in the high-pressure receiver 34, and the primary pressure P1
Higher. Since the pressure in the high-pressure receiver 34 is reported to the pressure regulator 17 as a control pressure (as indicated by the dashed line), the desired predetermined secondary pressure P2
When pressure is reached, an actuation method is possible in which the pressure regulating device 17 stops the supply of fluid to the valve means 15.

The above-described method of actuation of the device 1 requires actuation of the valve means 15 depending on the axial position of the working unit 7 with respect to the housing 2. This is the valve means 1
5, two control valves 38 and 38 provided upstream of the actuation means 24.
In this embodiment using the piston rods 6 and 38 '
, And thus actuate or reverse the valve means 15, respectively. The latter effect occurs because the control valve controls the supply of working fluid to the actuating means 24 of the valve means 15.

The advantage here is that the piston rod 6 itself is a component of the two control valves. That is, the piston rod constitutes a control member of the control valve, and is fixed to the housing.
And 38 'cooperate with the sealing part to control the supply of working fluid to the working means 24.

The sealing parts 43 and 43 ′ are provided in the partition wall 3 of the housing 2 through which the piston rod 6 penetrates, and in the present embodiment shown are each delimited by at least one annular seal 44. However, the annular seal 44 has a through hole 8
Is fixed so that it does not move in the axial direction in the groove on the outer periphery of. Suitably, the seal 44 is a lip seal, also referred to as a groove ring.

The piston rod 6 is coaxially surrounded by the sealing portions 43 and 43 ′. Optimally, the sealing portions 43 and 43 'are located slightly axially away from the end faces 45 and 45' of the bulkhead 3 delimiting the associated piston chambers 4 and 4 '.

Each of the sealing portions 43 and 43 ′ is disposed axially between the first fluid space 46 and the second fluid space 47. The first fluid space 46 is, in the case of this embodiment,
Each of the working spaces 12 and 12 ′ on the adjacent piston rod side is connected to each other via an annular space that is relatively short in the axial direction between the passage hole 8 and the outer peripheral surface of the piston rod 6. The first fluid space 46 can also be formed directly by the adjacent working space on the piston rod side.

In the present embodiment, the second fluid space 47 is formed between the outer peripheral surface of the piston rod 6 and the inner peripheral surface of the passage hole 8 and is provided in the sealing portions 43 and 43 ′ in an annular direction. Is constituted by an intermediate space. In order to prevent the two fluid spaces 47 from communicating with each other via the through holes 8, the fluid spaces are respectively sealed in the partition walls 3 on the side surfaces facing the sealing portions 43 and 43 ′ in the axial direction. In the present embodiment, each of the second fluid spaces 47 includes the sealing portions 43 and 4.
Since the other sealing portion 48 is located on the side opposite to the axial direction 3 ′, such sealing is ensured. However, the other sealing portion 48 is always in close contact with the outer peripheral surface of the piston rod 6. Again, most preferably, it comprises an annular seal, particularly in the form of a lip seal or groove ring. In this connection, a leak-removing duct 49, shown in phantom, may be provided, which on the one hand is open in the longitudinal part of the through-hole 8 between two further sealing parts 48 and on the other hand the housing 2
To the outer surface of the housing, so that any leaks occurring are eliminated.

The fluid control function of the piston rod 6 is made possible by the fact that the piston rod 6 has a contour made over the entire length according to the desired control function. Since this profile changes over the entire length of the piston rod 6, two fluid spaces 4
In order to control the fluid connection between 6 and 47, a stroke-dependent cooperation between the piston rod 6 and the sealing parts 43 and 43 'can be produced. Since the second fluid space 47 is in communication with the aforementioned working duct 22 which leads to the working means 24, it ensures the actuation of the valve means 15 in which the working fluid and thus the actuation signals from the piston rod side spaces 12 and 12 'are obtained. Can be

The piston rod 6 of the present embodiment has the partition wall 3, and has a role of blocking fluid coupling between the two fluid spaces 46 and 47. It is quite long. The piston rod 6 has sealing portions 43 and 4
When in a position that overlaps one of the 3's, it closely fits or fits with the sealing portions 43 and 43 ', resulting in a closed position, between the two adjacent first and second fluid spaces 46 and 47. Has such an outer shape that the fluid connection of is interrupted. When in the closed position, the seal 52 is axially aligned with the associated sealing portion 43 and 43 'and is hermetically enclosed by the sealing portion or by the respective seal 44 respectively.

Furthermore, the piston rod 6 has on each side of the sealing part 52 two axially spaced longitudinal parts which are axially adjacent to each other, these longitudinal parts being two sets of fluid spaces 46 and 47. It serves to release the fluid connection between them according to the stroke and is therefore referred to as flow transmission parts 53 and 53 '. The flow transmitters 53 and 53 'are located at the locations of the associated sealing parts 43 and 43' and one of the fluid spaces 46 and 47.
When the at least one transfer cavity 54 is formed, the outer shape is arranged so as to be arranged at least partially radially away from the respective sealing portions 43 and 43 '. Each position is referred to as a transfer position because the transfer cavity 54 creates a coupling between the two fluid spaces 46 and 47, thereby allowing fluid to pass through the associated sealing portions 43 and 43 '. You.

In order to obtain a sufficient flow or flow rate of the fluid, the shape of each transmission part 53 and 53 ′ is formed by cutting a groove-shaped recess surrounding the piston rod 6, as shown in FIG. It is preferable that the moving gap 54 has a shape of an annular gap. However, one or more partial recesses could alternatively be provided in the transmissions 53 and 53 'on the outer circumference of the piston rod. Importantly, in the transmissions 53 and 53 ', the piston rod 6 has a smaller or smaller cross-section over a sufficient length than the closure 52 or the respective sealing 43 and 43'. It is.

Normally, the pistons 5 and 5 ′ are arranged such that the pistons 5 and 5 ′
The sealing portion 52 is shaped so as to always have an effect until it reaches a position adjacent to or fitted to the sealing member. Therefore, in this example, the transmission parts 53 and 53 'are provided at positions slightly away from one of the two pistons 5 and 5'.

For this reason, during the stroke, the sealing part 52 has two sealing parts 43 and 43 ′.
By cooperating with the control valve is closed. Conversely, when one of the pistons 5 and 5 'reaches the end position, the associated transmissions 53 and 53' assume the transmission position, so that the high-pressure fluid flows into the associated working space 12 and 12 'on the piston rod side.
Through the transfer cavity 54, which has been unsealed, and can pass as a working fluid to the valve means 15 via the adjacent working duct 22. Thus, the valve means 15 initiated by fluid energy without the need for mechanical valve actuation by a driven functional work unit and without resorting to specially used sensor means.
Switching or inversion occurs.

The pressure accumulated in the actuator 22 is controlled by the associated control valves 38 and 38
In order to lower rapidly after closing, each working duct 22 is provided with a suitable vent 55
It has. In the embodiment shown, such a means allows the respective working duct to communicate with the outside air and does not prevent the establishment of the pressure required for the switching, but can cause the pressure to equalize with the outside air. It takes the form of a nozzle or chalk.

It is convenient to provide a logic circuit, not shown, preferably in the bulkhead, such that the primary pressure is applied simultaneously in the two duct sections on the piston space side of the first primary duct device 14. Switchover or reversal of the valve means 15 if the primary pressure is not applied at all.

In the embodiment shown, the valve device 15 is mounted on a housing, more particularly with a sub-plate or an intermediate plate between them. However, it will be appreciated that the valve arrangement may be fully or at least partially integrated within the housing, more particularly within the septum. Further, as a supplement, FIG. 1 includes a symbolic circuit diagram for clarifying the valve function of the valve means 15.

In the case of differently configured actuators, more particularly in the case of a conventional fluid energy cylinder type construction having a single piston, a piston rod can be used as a control member for one or more control valves. It should be clear.

[Brief description of the drawings]

1 shows, by way of example, a configuration of a fluid-driven actuator in the form of a pressure booster in a preferred configuration and in a longitudinal section along the line II in FIG. 2;

2 is a cross-sectional view of the device shown in FIG. 1 along the line II-II in FIG. 1;

──────────────────────────────────────────────────続 き Continued on the front page (71) Applicant Ruiter Strasse 82, 73734 Esslingen, Germany (72) Inventor Muller Gerald Germany 70329 Stutt Gard Woolbacher Strasse 60 F-term (reference) 3D048 BB43 BB59 FF01 FF11 FF23 PP03

Claims (16)

[Claims] 1. A housing (2), said housing (2) being powered by fluid energy.
Piston rod (6) to be moved with respect to
6) A fluid-driven actuator including at least one control valve (28 and 28 ') operable in accordance with the position of (6), said control valve cooperating with a sealing part (43 and 43'). A control member for controlling the fluid connection between the two fluid spaces (46 and 47), the sealing part being fixed to the housing, the control member having a corresponding outer peripheral surface; Fluid actuated device characterized by being directly constituted by a piston rod (6). 2. The actuator according to claim 1, wherein the two fluid spaces are provided.
(46 and 47) are, on either side, axially adjacent to the sealing part (43 and 43 ') coaxially surrounding the piston rod,
6) has at least one vertical part (sealing part 52) which plays a role of blocking fluid coupling, and when the vertical part takes a position (sealing position) overlapping the sealing parts (43 and 43 '), the sealing part is closed. The piston rod (6) is formed so as to be in intimate contact with the parts (43 and 43 '), and has at least one vertical part (transmission parts 53 and 53') serving to release the fluid connection. The vertical portion takes a position (transmission position) that overlaps the sealing portion (43 and 43 ′), and the fluid space (46 and 47)
When at least one movement gap (54) is formed, the gap is formed so as to be at least partially radially separated from the sealing portions (43 and 43 '). Actuating device. 3. The actuating device according to claim 2, wherein the transmitting portions (53 and 5) are arranged in parallel.
3 ') is an actuating device characterized in that it comprises a groove-like recess surrounding said piston rod (6). 4. The actuating device according to claim 2, wherein one of the fluid spaces (47 and 47) is adjacent to the piston rod (6) and has one axial direction. There is a sealing portion (43 and 43 ') of the control valve (38 and 38') on the side surface of the valve, and another sealing portion (48) contacting the piston rod (6) on the other axial side surface. An actuating device characterized by having: 5. The actuating device according to claim 4, wherein the piston rod is adjacent to the further sealing part (48) on an axial side opposite the adjacent fluid space (47). An actuating device, wherein the surrounding space is connected to a leak elimination path 49. 6. The actuating device according to claim 1, wherein the piston rod (6) is provided in the housing (2) with two working spaces (12 and 12 ′; 13 and 13 ') are connected to at least one piston (5 and 5') separating them from each other, and one of the fluid spaces (46) is connected to the working space (12 and 12 ') on the piston rod side. Or an operating device constituted by the working space. 7. The actuating device according to claim 1, wherein the valve means (15) comprises at least one control valve (38 and 38 ').
An actuating device characterized by being actuated by: 8. The actuating device according to claim 7, wherein the valve means (15).
Is provided for presetting a magnitude of a stroke of the piston rod (6). 9. The actuating device according to claim 7, wherein a fluid actuation signal for the valve means (15) is issued from the second fluid space (47). Actuating device. 10. The actuating device according to claim 7, wherein:
An actuating device, characterized in that said valve means (15) is externally mounted on said housing (2) or at least partially integrated in said housing (2). 11. The actuating device according to claim 1, wherein the at least one control valve has a sealing portion.
Actuating device (43 and 43 ') provided in a wall (3) of said housing (2), said wall having a piston rod (6) extending therethrough. . 12. The actuating device according to claim 1, wherein the sealing part (43 and 43 ′) is delimited by an annular seal (44), more particularly by a lip seal. An actuating device characterized by being defined. 13. The actuating device according to claim 1, characterized by an arrangement in the form of a pressure booster, wherein the housing (2)
) Is 2 by pistons (5 and 5 ') connected to said piston rod (6).
Means (32), comprising at least one piston chamber (4 and 4 ') divided into two fluid pressurizable working spaces (12 and 12'; 13 and 13 ');
As a result, the working space (1 and 12 ′) on the piston rod side is removed from the working space (1).
During this stroke movement, which occurs as a reduction of the volume of 2 and 12 '), a supply is made to the high-pressure receiver (34) and the working space (12 and 12') on the piston rod side.
2.) An actuating device provided with control valves (38 and 38 ') to provide valve means (15) for reversing the direction of the stroke of said piston rod (6) by means of a fluid actuating signal resulting from (1). 14. The actuating device according to claim 1, wherein the housing (2) comprises two piston chambers (4 and 4 ') separated from one another by a partition (3). The piston chamber (5 and 5 ') respectively.
Are provided to separate the two working spaces (12 and 12 '; 13 and 13'), said two pistons (5 and 5 ') being fixedly connected to each other by said piston rod (6). A functional working unit (7) is formed, said piston rod (6)
) Extends through said bulkhead (3), and is further provided with two control valves (38 and 38 '), said sealing part (43 and 43') being penetrated by said piston rod (6). Provided in the passage hole (8) of the partition wall (3) extending in parallel, and having two associated fluid spaces (4).
6) each of the adjacent working spaces (12 and 12 ') on the piston rod side
Or the other two fluid spaces (47) formed by or connected to the working space, the working duct (22) extending at least partially into said bulkhead (3)
Connected to said actuating means (24) of the fluid-operated valve means (15) via: a further primary ducting device (14) is provided, via which the functional working unit (7) Fluid is alternately supplied to said outer working space (13 and 13 ') via said valve means (15) in order to shift axially one or the other, and a second primary duct device (25), through which the two working spaces (12 and 12 ') on the piston rod side are acted upon by the fluid exposed to the primary pressure via the intermediary of the first check valves (26 and 26'). The secondary duct device (32) receives the fluid that has flowed out of the working space (12 and 12 ') on the piston rod side via the second check valve (37 and 37'), and the high-pressure receiver (34) Return to It is provided in order to fulfill the split, actuating device characterized by construction as a pressure boost device. 15. The actuating device according to claim 14, wherein a logic circuit is more specifically provided in the partition (3) and the duct (25) of the second primary duct device (25).
19 the circuit causes the switching of the valve means (15) when there is simultaneously no pressure or primary pressure in the outer working space (13 and 13 ') from the valve means (15). Actuating device characterized by the above. 16. An actuating device according to claim 14 or claim 15, wherein
Venting means (55) for the working duct (22) are provided, said venting means being effective when the associated control valve (38 and 38 ') is shut off by said piston rod. Actuator.