JP2019044970A - Hydraulic cylinder with cooling medium chamber - Google Patents

Abstract

To provide a hydraulic cylinder having a fluid cooling part suited for a closed type circuit.SOLUTION: A hydraulic cylinder comprises: a cylinder tube 2 extending along a longitudinal axis 10, in which a plunger 32 can be received in the cylinder tube 2 displaceably along the longitudinal axis 10; and a sleeve tube 4 extending at least parallel to the longitudinal axis 10 and at least partially surrounding the cylinder tube 2 such that a cooling chamber 14 is formed between the cylinder tube 2 and the sleeve tube 4. A working fluid can flow through the cooling chamber 14, and the cooling chamber 14 is prepared to cool the working fluid flowing through the cooling chamber 14.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a hydraulic cylinder comprising a cylinder tube extending along a longitudinal axis, in which the plunger can be accommodated displaceably along the longitudinal axis. The invention also relates to a hydraulic cylinder arrangement comprising such a hydraulic cylinder.

BACKGROUND OF THE INVENTION In an open fluid circuit, a working fluid, such as hydraulic fluid, is normally pumped from a tank to a pump, from there to a consumer and from there to a tank, with the working fluid warming up Do. It is common to direct the working fluid between the consumer and the tank through a so-called reflux condenser, such as, for example, the SKI series or the EKM / SKM series of HBE hydraulic components, in order to dissipate the heat. Alternatively, separately pumped cooling circuits are known, connected to the tank, such as, for example, the TFS / A series of HBE hydraulic components. Alternatively, cooling devices arranged or immersed in a tank, such as, for example, the UKC-G series of HBE hydraulic components, are also known.

  In closed fluid circuits, the working fluid is normally pumped from the pump to the consumer and back to the pump, with the tank usually being provided at most to compensate for fluid volume and the fluid Not involved in the circuit. The relatively small total volume of fluid often does not provide a cooling device.

  An example of such a closed fluid circuit is the so-called free standing shaft (autarke Achse). This fluid circuit may, for example, be a hydraulic circuit which is electrically controlled and driven. The hydraulic circuit comprises a hydraulic cylinder having a plunger displaceable between two working chambers, and a pump disposed between the working chambers and fluidly coupled via the working chamber and the pipeline. In most cases, the pump provided for actuation is arranged directly on the hydraulic cylinder as a control block, together with a valve provided for control and a small tank provided for volume compensation. This makes it possible to obtain a structural group of compact dimensions. For exhaust heat, in most cases only heat dissipation from the surfaces of the hydraulic cylinder and control block is assumed. The cooling unit associated with the tank is often not sufficient for the fluid located in the closed circuit. Reflux cooling as a separate structural part is usually not used, for example to avoid pressure pulsations.

SUMMARY OF THE INVENTION The problem underlying the invention is therefore to propose a fluid cooling part which is suitable for closed circuits.

  The subject is a hydraulic cylinder, which extends along a longitudinal axis, in which a plunger can be accommodated displaceably along the longitudinal axis. A sleeve tube, the sleeve tube comprising a sleeve tube extending at least parallel to the longitudinal axis and at least partially surrounding the cylinder tube, whereby between the cylinder tube and the sleeve tube A cooling chamber is formed, through which the working fluid can flow, and the cooling chamber is solved by a hydraulic cylinder, which is arranged to cool the working fluid flowing through the cooling chamber . By flowing the working fluid through the entire fluid chamber, a surface that is greatly enlarged relative to the conventional fluid flow path and to the cylinder tube, ie, the surface of the sleeve tube, is provided for heat dissipation.

  Preferred refinements of the invention are the subject matter of the dependent claims.

  The cylinder tube, which is able to accommodate the plunger displaceably along the longitudinal axis, is provided to support the plunger and / or mechanically with a lateral force and / or pressure and / or the like. It can be understood as a cylinder tube which is arranged to absorb. Thus, this hydraulic cylinder is also suitable for high pressures and high loads.

  A sleeve tube at least partially surrounding the cylinder tube may be provided to surround the cylinder tube at least partially and radially outward with respect to the longitudinal axis, whereby the heat is interacted with by the interaction with the surroundings. It can be released efficiently.

  A further embodiment may be provided, in which the cylinder tube and the sleeve tube are arranged substantially coaxially with one another so that a uniform thickness of the cooling chamber and thus a uniform heat dissipation can be achieved.

  The cooling chamber is at least partially configured as an annular chamber, whereby the cooling chamber encloses the cylinder tube extensively, so that a further aspect is provided, by which the surface of the sleeve tube can be largely dimensioned. May be

  A further aspect may be provided in which the cooling chamber is configured fluid tight, thereby avoiding leakage.

  A further aspect may be provided in which the cooling chamber is configured in a working pressure, whereby leakage is avoided even when working pressure is applied.

  In the cylinder tube, at least one working chamber can be defined by the plunger, and the cooling chamber may be provided with a further aspect that is at least in fluid communication with the at least one working chamber or the aforementioned working chamber. Thus, the fluid can be cooled by flowing in the cooling chamber as it flows into and out of the working chamber. Even if the cooling chamber is in fluid communication with the working chamber, it is possible to realize free fluid exchange between the working chamber and the cooling chamber, at least to a limited extent, and And / or fluid loss can be avoided. The feature that at least one working chamber can be defined by the plunger in the cylinder tube may be combined separately with another feature for defining the working chamber.

  One cylinder end and / or one cylinder end is provided on the axial end side, the cylinder end closing the cooling chamber and / or the cylinder tube in a tight manner, respectively, so that separate cooling Additional aspects may be provided in which the chamber closure may be omitted. In this case, close closure is understood to mean, in particular, that the cylinder end comprises, for example, at least one, in particular a penetration guide with sealing means, such as a fluid line, a plunger rod, a sensor system feed or the like. be able to.

  For example, the working fluid to be moved by the pump has a small mass, since one cylinder end can connect the cooling chamber to one working chamber and thereby achieve a short pipeline path or fluid path. There may be further aspects provided that the system weight can be reduced. If the aforementioned working chamber is a working chamber adjacent to the cylinder end, even shorter pipeline paths can be achieved. If the aforementioned working chamber is one of a plurality of working chambers, it is technically easy to use a plunger which acts bi-directionally, for example for both rod cylinders or differential cylinders. If the cylinder end fluidically couples and / or communicatively couples the cooling chamber to one work chamber, a joint which saves costs can be selected in particular. If the cylinder end couples the cooling chamber with the working chamber via a switch, additional functions can be advantageously incorporated. Such switches may be one or at least one valve such as a pure line, directional control valve, switchable valve, non-switchable valve, pressure regulating valve, volume flow regulating valve, etc., end position damper , And a subset thereof and / or a combination thereof.

  One cylinder end couples the cooling chamber with the connection so that the cooling chamber can be integrated into the fluidic switch.

  A further embodiment may be provided in which one cylinder end couples one working chamber with one connection via a cooling chamber, whereby the cooling chamber can be integrated into the fluid switch . If the connection is an external connection, such as a connection leading out of the cylinder, another device can be connected suitably. If the connection is a fluid connection and / or a fluid connection, one can in particular select a cost saving connection. If the cylinder end couples the cooling chamber with the connection via a switch, additional functions can be preferably incorporated.

  A further embodiment may be provided in which one cylinder end couples one working chamber to one connection, whereby the corresponding working chamber can be coupled to a fluid source. The work rooms may be adjacent work rooms. The connection may be an external connection. The cylinder end may couple one working chamber in fluid connection and / or in fluid communication with the connection and / or via a switch. In doing so, reference is made to the aforementioned characteristics and advantages.

  A cylinder end couples one working chamber with one connection via a cooling chamber, and a cylinder end couples another working chamber with another connection, thereby both The working chamber has one connection at the same end of the cylinder, so that both connections can be arranged, for example, preferably in space.

  Although this is also independently claimable, a further embodiment may be provided in which the cooling chamber is divided into a working fluid section and a cooling medium section. Thereby, a cooling medium can be supplied.

  There may be further embodiments in which these sections are separated from one another in a fluid tight and / or working consolidation manner. This can avoid mixing of the cooling medium and the working fluid.

  A further embodiment may be provided, wherein the cooling medium section is arranged to be flowed by the cooling medium. Special suitability then preferably exists.

  A further aspect may be provided in which the cooling medium section is coupled to the connection, whereby the cooling medium can be coupled to the cooling medium source or the temperature reservoir. If the cylinder end joins the coolant section with the connection, the connection can avoid an increase in the cooling efficiency in the cooling chamber.

  A further embodiment may be provided, wherein the working fluid section and / or the cooling medium section are configured as a conduit extending in the cooling chamber. This allows the use of proven fabrication techniques of conduit structures.

  Although this is also independently claimable, a further embodiment may be provided, in which the conduit section is at least partially wound about the longitudinal axis. This allows the conduits to be mounted in the cooling chamber in a space-saving or high space proportion, which increases the efficiency.

  Although this is also independently claimable, a further embodiment may be provided, in which the conduit section is configured at least partially inclined along the longitudinal axis. This allows, for example, the fluid flowing through the cooling chamber along the longitudinal axis to exchange heat with the fluid flowing in the duct over a particular section.

  Although this is also independently claimable, a further embodiment is provided in which the conduit section is at least partially wound about the longitudinal axis and configured to be inclined along the longitudinal axis. It may be done. Thus, it is possible to provide a helically wound and inclined channel. This structure results in a particularly high space fraction of the conduit in the cooling chamber. For example, if the cooling chamber is configured as an annular chamber, the conduit configured as a spiral or coiled tube can occupy up to about 79% (= π / 4) of the space. If, for example, the cooling medium flows through the pipeline and the hydraulic fluid flows through the remaining annular chamber-like cooling chamber, it is possible to reduce the volume of the hydraulic fluid significantly, which should be moved by the pump Volume is reduced, response and cycle time are improved.

  There may be further aspects provided that the conduits are arranged in multiple layers, which can further improve the space utilization in the cooling chamber. Such measures are recommended to increase the efficiency, in particular for very short cylinders. The multi-layered pipeline can reduce the volume fraction of the remaining cooling chamber volume preferably to about 9%.

  The working fluid section and the cooling medium section can be flowed or overflowed in countercurrent connection, whereby a particularly efficient cooling can be achieved. For example, since the working fluid segment is used as a feedway to the hydraulic cylinder work chamber, if the working fluid segment is conducted in a changing flow direction, a flow redirecting switch for changing the coolant flow direction to the cooling media segment Or it can be connected to the upstream side of the pipeline. The 4-port 3-position directional control valve is a reliable flow redirecting switch.

  Although this is also independently claimable, the hydraulic cylinder arrangement may be provided with hydraulic cylinders as described above, which results in a structural group. Such a hydraulic cylinder arrangement may be provided with a plunger which is preferably accommodated in the cylinder tube. Such hydraulic cylinder arrangement may additionally or alternatively preferably be provided with a working fluid pump. Such a hydraulic cylinder arrangement may additionally or alternatively preferably be provided with a tank. If the tank is provided for temperature compensation and / or leak compensation for the working fluid and / or compensation for the plunger rod volume, a very small tank with small mass and small construction space can be provided. On the contrary, if the tank is only provided for temperature compensation and / or leak compensation for the working fluid and / or for compensation of the plunger rod volume, a particularly very small tank with a particularly low mass and a particularly small construction space is provided. be able to. Such a hydraulic cylinder arrangement may additionally or alternatively preferably be provided with a control unit. The control unit may be arranged to control and / or drive the plunger movement, the control unit being for example at least one control valve and / or a pump and / or for example an electrical pump, as described above. Control devices and / or logic such as may include drives and / or tanks and / or electrical switches and / or fluid switches and / or standardized interfaces and / or electronic control units (ECUs) It may include a switch. The control unit may be usually electromechanical, ie it comprises at least two, preferably mutually coordinated, various types of components or mutually integrated subcomponents, For example, it can be selected from the group comprising components related to mechanical, hydraulic, pneumatic, electrical, electronic, physical, chemical and / or internal combustion engines.

  In the following, two preferred embodiments of the invention will be described in detail on the basis of schematic drawings.

The hydraulic cylinder in the first embodiment of the present invention is shown in principle in longitudinal section. The hydraulic cylinder in the 2nd embodiment of this invention is shown with a longitudinal cross-sectional view roughly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows a hydraulic cylinder 1 in principle longitudinal section. The hydraulic cylinder 1 has one cylinder pipe 2, one sleeve pipe 4, two cylinder ends 6 and one pipe 8.

  The cylinder tube 2 extends along the longitudinal axis 10. The cylinder tube 2 defines a cylinder chamber 12. Within the cylinder chamber 12, a plunger (not shown) can be accommodated along the longitudinal axis 10 and can be displaced while exerting and / or forming a pressure differential. The sleeve tube 4 is arranged coaxially with the cylinder tube 2 so that the longitudinal axis of the sleeve tube 4 (not itself shown) is at a zero distance to the longitudinal axis 10 of the cylinder tube 2 Extend in parallel. In this case, the sleeve tube 4 encloses the cylinder tube 2 so that the sleeve tube 4 is provided radially outward of the cylinder tube 2 with respect to the longitudinal axis 10 and the sleeve tube 4 is at the longitudinal axis 10 It extends along the side next to the cylinder tube 2. The cylinder tube 2 and the sleeve tube 4 together define a cooling chamber 14, which is configured as an annular chamber or an annular intermediate chamber between the tubes 2, 4.

  The cylinder chamber 12 and the cooling chamber 14 are each defined by the cylinder end 6 at the axial end side. The cylinder end 6 seals the chambers 12, 14. Chambers 12 and 14 are configured to be operationally compacted not only for tubes 2 and 4 and cylinder end 6 but also for those joints not shown in detail, whereby chambers 12 and 14 are normally used in the industry. Works at least in a tight manner, even with internal / external pressure applied.

  A conduit 8 is arranged in the cooling chamber 14. The line 8 divides the cooling chamber 14 into two sections, a working fluid section 16 and a cooling medium section 18. In this case, the space in the conduit 8 is the cooling medium segment 18 and the space in the cooling chamber 14 outside the conduit 8 is the working fluid segment 16. The line 8 has three sections along the longitudinal axis 10, namely a feed section 20, a heat exchange section 22, which may also be referred to as a spiral section, and another feed section 20. The feed section 20 is arranged to fluidly couple the heat exchange section 22 with a source of coolant (not shown) and / or a coolant temperature reservoir (not shown). The heat exchange section 22 is arranged in the cooling chamber 14. The heat exchange section 22 extends obliquely upward to the right along the longitudinal axis 10. The heat exchange section 22 is wound around the longitudinal axis 10. The heat exchange section 22 is thus configured as a coil or a spiral or a winding.

  The feed section 20 extends through the cylinder end 6. A working fluid path 24 also extends through the cylinder end 6, which directs the working fluid into the cooling chamber 14, more precisely into the working fluid section 16 and out there. It is prepared as. The working fluid flow 26 and the cooling medium flow 28 are indicated by the arrows in FIG. The cooling chamber 14 with the line 8 is connected in the present embodiment as a countercurrent device, in which the flow of the working fluid flow 26 and the flow of the cooling medium flow 28 are directed oppositely to each other. They are guided by each other in the flow direction.

  Hereinafter, the second aspect of the present invention will be described with reference to FIG. The part corresponding to the first aspect has the same reference numeral, and the part will not be described anew.

  Unlike the hydraulic cylinder 1 of the first aspect, in the second aspect, the conduit 8 is not provided in the cooling chamber 14.

  FIG. 2 shows a hydraulic cylinder device 30. The hydraulic cylinder device 30 further includes a plunger 32 and a control unit 34 in addition to the hydraulic cylinder 1, the cylinder pipe 2, the sleeve pipe 4, the cylinder end 6, the cylinder chamber 12 and the cooling chamber 14. The plunger 32 is disposed and accommodated in the cylinder tube 2. Since the hydraulic cylinder 1, the hydraulic cylinder device 30 and the plunger 32 are configured in a differential structure, it is preferable that the plunger 32 be attached to the plunger head 36 in the opposite direction to each other. Have two plunger rods 38 having the same diameter. The control unit 34 does not draw in detail, but has an electric motor which drives the pump and which is controlled with the valve.

  The hydraulic cylinder device 30 is a closed or free standing system. The plunger head 36 divides the cylinder chamber 12 into two working chambers 40. One of the cylinder ends 6, ie here the left cylinder end 6 in FIG. 2, directly operates one of the working chambers 40, ie here adjacent in FIG. 2, ie the left working chamber 40 It is coupled to the connection 42 through the fluid path 24. The same cylinder end 6, here the left cylinder end 6 in FIG. 2, couples another connection (not shown) to the cooling chamber 14 via another working fluid path 24. The other cylinder end 6, ie here the right cylinder end 6 in FIG. 2, connects the cooling chamber 14 with the other working chamber 40, ie here adjacent or right working chamber 40 in FIG. . In order to displace the plunger 32 from left to right in FIG. 2, the pump on the suction side passes the working fluid from the right working chamber 40 through the right cylinder end 6 and through the cooling chamber 14 and The connection (not shown) is pumped into the control unit 34 and there from the outlet side the connection 42 and the left cylinder end 6 without any intervening tank or the like from there. It is pumped through the left working chamber 40. In this case, the working fluid is heated because energy is supplied to the working fluid. At the same time, the working fluid flowing through the cooling chamber 14 is via the sleeve tube 4 (the sleeve tube 4 may for example be made of metal, and in one variation may have cooling ribs or the like) Release heat energy to the surroundings.

  Thus, it is a hydraulic cylinder 1, which is a cylinder tube 2 extending along the longitudinal axis 10, in which a plunger 32 can be accommodated displaceably along the longitudinal axis 10. A cylinder tube 2 and a sleeve tube 4, the sleeve tube 4 extending at least parallel to the longitudinal axis 10 and at least partially surrounding the cylinder tube 2; Thus, a cooling chamber 14 is formed between the cylinder tube 2 and the sleeve tube 4 so that the working fluid can flow through the cooling chamber 14, and the cooling chamber 14 is a working fluid flowing through the cooling chamber 14. A hydraulic cylinder is disclosed that is provided to cool the

Claims (12)

A hydraulic cylinder,
A cylinder tube (2) extending along a longitudinal axis (10) in which the plunger (32) can be displaceably accommodated along said longitudinal axis (10) With the cylinder tube (2),
A sleeve tube (4) extending at least parallel to the longitudinal axis (10) and at least partially surrounding the cylinder tube (2);
Equipped with
A cooling chamber (14) is formed between the cylinder pipe (2) and the sleeve pipe (4), through which working fluid can flow, and the cooling chamber (14). A hydraulic cylinder, provided to cool the working fluid flowing through the cooling chamber (14).   The cylinder tube (2) and the sleeve tube (4) are arranged substantially coaxial to one another and / or the cooling chamber (14) is configured as an annular chamber. Hydraulic cylinder.   The hydraulic cylinder according to claim 1 or 2, wherein the cooling chamber (14) is configured in a fluid-tight and / or operative manner.   In the cylinder tube (2), at least one working chamber (40) can be defined by the plunger (32), and the cooling chamber (14) is at least fluidly coupleable with the at least one working chamber (40) A hydraulic cylinder according to any one of the preceding claims.   One cylinder end (6) is provided at each axial end, which cylinder end (6) tightly closes the cooling chamber (14) and / or the cylinder tube (2), respectively. A hydraulic cylinder as claimed in any one of the preceding claims.   The hydraulic cylinder according to claim 5, wherein one cylinder end (6) couples the cooling chamber (14) with one working chamber (40).   One cylinder end (6) couples one working chamber (40) with one connection via the cooling chamber (14) and / or one cylinder end (6) or 7. The hydraulic cylinder as claimed in claim 5, wherein the cylinder end (6) combines one working chamber (40) with one connection (42).   Said cooling chamber (14) is divided into a working fluid section (16) and a cooling medium section (18), said sections (16, 18) being separated from one another in a fluid-tight and / or working-tight manner 8. A hydraulic cylinder as claimed in any one of the preceding claims, characterized in that and / or the cooling medium section (18) is arranged to be flowed by means of a cooling medium.   9. A hydraulic cylinder as claimed in claim 8, wherein the working fluid section (16) and / or the cooling medium section (18) are configured as a conduit (8) extending into the cooling chamber (14).   The conduit (8) is at least partially wound around the longitudinal axis (10) and / or is formed inclined along the longitudinal axis (10) 10. A hydraulic cylinder according to item 9.   11. A hydraulic cylinder as claimed in claim 9, wherein the ducts (8) are arranged in multiple layers.   A hydraulic cylinder (1) according to any one of the preceding claims, a plunger (32) housed in a cylinder tube (2) and / or a working fluid pump and / or a working fluid A hydraulic cylinder arrangement comprising: a tank adapted for temperature compensation and / or leak compensation and / or a plunger rod volume compensation and / or a control unit (34).

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