DE102017215678A1 - Hydraulic cylinder with coolant chamber - Google Patents

Abstract

Disclosed is a hydraulic cylinder with a cylinder tube (2) extending along a longitudinal axis (10), in which a piston (32) can be received displaceably along the longitudinal axis (10), and with a cladding tube (4) which is at least parallel to the Extends longitudinal axis (10) and the cylinder tube (2) at least partially surrounds, so that between the cylinder tube (2) and the cladding tube (4) a cooling chamber (14) is formed, which can be flowed through by a working fluid and for cooling the cooling chamber (14) is prepared by passing working fluid.

Description

Field of the invention

The invention relates to a hydraulic cylinder having a cylinder tube extending along a longitudinal axis, in which a piston can be received displaceably along the longitudinal axis. The invention also relates to a hydraulic cylinder device with such a hydraulic cylinder.

Background of the invention

In an open fluid circuit, a working fluid, such as a hydraulic oil, is generally conveyed from a tank to a pump, from there to a consumer, and from there to the tank, with the working fluid being heated. To dissipate the heat, it is common practice to pass the working fluid between the consumer and the tank through a so-called return cooler, such as the SKI series or the EKM / SKM series from HBE hydraulic components. Alternatively, separately-connected cooling circuits connected to the tank are known, such as the TFS / A series from HBE hydraulic components. Alternatively, cooling devices disposed in or immersed in the tank are also known, such as the UKC-G series from HBE hydraulic components.

In a closed fluid circuit, the working fluid is generally conveyed from a pump to a consumer and back of the pump, a tank is usually provided at most for fluid volume compensation, and he does not participate in the fluid circuit. Also, because of the relatively small total fluid volume, a cooling device is often not provided.

An example of such a closed fluid circuit is a so-called autarkic axis. This may, for example, be an electrically controlled and driven hydraulic circuit which has a hydraulic cylinder with a piston displaceable between two work spaces and a pump arranged between the work spaces and fluidly connected to the latter via lines. In this case, often provided for driving the pump with valves provided for control and provided with a volume compensation, small tank as a control block directly to the hydraulic cylinder, so that an assembly with compact dimensions can be obtained. For heat dissipation often only heat radiation from the surfaces of the hydraulic cylinder and the control block is provided. Cooling associated with the tank often does not adequately cool the closed loop fluid. A return cooling as a separate component is usually not used for example to avoid pressure pulsations.

Disclosure of the invention

In contrast, the invention has for its object to propose suitable for closed circuits fluid cooling.

This object is achieved by a hydraulic cylinder having a cylinder tube extending along a longitudinal axis, in which a piston can be received displaceably along the longitudinal axis, and having a cladding tube which extends at least parallel to the longitudinal axis and at least partially surrounds the cylinder tube, so that between the Cylinder tube and the cladding tube, a cooling chamber is formed, which can be flowed through by a working fluid and for cooling the working fluid flowing through the chamber is prepared. By the entire fluid chamber is flowed through by the working fluid, is compared to a conventional fluid line and relative to the cylinder tube significantly enlarged surface, namely the surface of the cladding tube, for heat dissipation available.

Advantageous developments of the invention are the subject of the dependent claims.

A cylindrical tube in which a piston can be received in a displaceable manner along the longitudinal axis can be understood to mean a cylinder tube which is prepared to support the piston and / or which is prepared for this, a transverse force and / or a pressure force and / or the like pick up mechanically. Thus, the hydraulic cylinder is also suitable for high pressures and high loads.

The cladding tube, which surrounds the cylinder tube at least partially, the cylinder tube may be at least partially and provided radially outwardly with respect to the longitudinal axis surrounding to be able to effectively release heat by interacting with the environment can.

Developing can be provided that the cylinder tube and the cladding tube are arranged approximately coaxially with each other, so that a uniform thickness of the cooling chamber and therefore a uniform heat dissipation can be achieved.

Developing can be provided that the cooling chamber is at least partially formed as an annular space, so that it surrounds the cylinder tube to a large extent, so that the surface of the cladding tube can be large.

Developing can be provided that the cooling chamber is formed fluid-tight, to prevent leakage

Further education can be provided that the cooling chamber is formed working pressure-tight to prevent leakage even when exposed to a working pressure.

Further, it can be provided that at least one working chamber can be defined in the cylinder tube by a piston, wherein the cooling chamber is at least fluid-communicable with at least one or the working space. Thus, the fluid can be cooled each time it flows in and out of the working space by flowing through the cooling chamber. If the cooling chamber is connected to the working space even communicating fluidly, can - at least to a limited extent - come about a free fluid exchange between the working space and the cooling chamber and / or flow losses can be avoided. The feature according to which at least one working space can be defined in the cylinder tube by a piston can also be combined in isolation with other features for defining a working space.

Further, it can be provided that a cylinder head and / or each cylinder head is provided axially end, which closes the cooling chamber and / or the cylinder tube each sealing, so that can be dispensed with a separate cooling chamber closure. In this case, sealing sealing can be understood in particular to mean that the cylinder head contains at least one bushing, in particular provided with a sealing means, such as a fluid line, a piston rod, a sensor cable or the like.

Further, it can be provided that a cylinder head connects the cooling chamber with a working space, so that short line paths or fluid paths can be achieved, so that, for example, a working fluid to be moved by a pump has a low mass, and the system weight can be reduced. If the working space is the working space adjacent to the cylinder head, even shorter line paths can be achieved. If the working space is one of the working spaces, technically, a double-acting piston, such as in a synchronous cylinder or a differential cylinder, can be used. If the cylinder head fluidly and / or communicatively connects the cooling chamber with a working space, particularly cost-saving connections can be selected. If the cylinder head connects the cooling chamber with the working space with the interposition of a circuit, additional functions can be advantageously integrated. Such a circuit may be a pure line, or at least one valve, such as a directional control valve, a switchable valve, a non-switchable valve, a pressure regulating valve, a volumetric flow regulating valve, a cushioning, a subset and / or a combination thereof be.

Further, it can be provided that a cylinder head connects the cooling chamber with a connection, so that the cooling chamber can be integrated into a fluid circuit.

Further development can also be provided that a cylinder head connects a working space with interposition of the cooling chamber with a connection, so that the cooling chamber can be integrated into a fluid circuit. If the port is an external port, such as a port leading out of the cylinder, additional devices may be advantageously connected. If the connection is a fluidic and / or communicating connection, particularly cost-saving connections can be selected. When the cylinder head connects the cooling chamber to the port with interposition of a circuit, additional functions can be advantageously integrated.

Further, it can be provided that a cylinder head connects a working space with a connection, so that the relevant working space can be connected to a fluid source. The work space may be an adjacent work space; the connection can be an external connection; the cylinder head can connect the working space with a connection fluidly and / or communicatively and / or by interposing a circuit; in this case, reference is made to the properties and advantages described above.

Further, it can be provided that a cylinder head connects a working space with interposition of the cooling chamber with a port and the cylinder head connects the other working space with another port, so that both work spaces each have a connection to the same cylinder head, so that both connections are structurally favorable, for example, arranged side by side could be.

Further education and also independently claimable can be provided that the cooling chamber is divided into a working fluid portion and a coolant portion, so that a coolant can be supplied.

Further, it can be provided that the sections are fluid-tight and / or working pressure-tightly separated from each other, so that mixing of the coolant with the working fluid can be avoided.

Further, it can be provided that the coolant section is prepared for being flowed through by a coolant, so that advantageously a particular suitability is present.

Further, it can be provided that the coolant section is connected to a port, so that the coolant can be connected to a coolant source or a temperature sink. When a cylinder head connects the coolant portion to a port, communication within the cooling chamber can be enhanced to increase the cooling efficiency.

Further, it may be provided that the working fluid portion and / or the coolant portion is formed as a running in the cooling chamber pipe, so that can be made of proven production techniques of piping construction.

Further education and also independently claimable can be provided that the pipe is at least partially wound around the longitudinal axis around, so that the pipe is space-saving or with a high proportion of space in the cooling chamber can be accommodated to increase the efficiency.

Developing further and independently claimable can be provided that the pipe is formed rising at least in sections along the longitudinal axis, so that, for example, along the longitudinal axis of the cooling chamber flowing fluid can occur over a certain distance with the fluid flowing in the pipe into a heat exchange.

Further development and also independently claimable can be provided that the pipeline is at least partially wound around the longitudinal axis and rising along the longitudinal axis formed. Thus, a helix-like winding and rising formed pipe can be provided. This design leads to a particularly high proportion of space of the pipeline in the cooling chamber. For example, if the cooling chamber is designed as an annular chamber, the pipe formed as a helix or pipe helix can take up to about 79% (= π / 4) of the space. For example, when coolant flows through the pipeline and hydraulic fluid is flowed through the remaining annular chamber, the volume of hydraulic fluid can be greatly reduced, reducing the volume to be moved by a pump and improving response and cycle time.

Developing can be provided that the pipeline is arranged in multiple layers, so that a space utilization in the cooling chamber can be further improved. Especially with very short cylinders, this approach is recommended to increase the effectiveness. By a multi-layer pipe, the volume fraction of the remaining cooling chamber volume can be advantageously reduced to about 9%.

Further, it can be provided that the working fluid section and the coolant section are flowed through or flushed through in a countercurrent circuit, so that a particularly efficient cooling can be achieved. When the working fluid section is flowed through in an alternating flow direction, for example, because the working fluid section serves as a supply line to a hydraulic cylinder working space, a flow direction switching circuit for coolant flow direction change can be connected upstream of the coolant section or the pipeline. One 3 / 4 -Way valve is a proven flow direction changeover circuit.

Weiterbildend and also independently claimable Hydraulikzylindervorrichung can be provided with a hydraulic cylinder as described above to obtain an assembly. Such a hydraulic cylinder device may advantageously be provided with a piston received in the cylinder tube. Such a hydraulic cylinder device may additionally or alternatively be advantageously provided with a working fluid pump. Such a hydraulic cylinder device may additionally or alternatively be advantageously provided with a tank. If the tank is prepared for temperature compensation and / or leakage compensation and / or piston volume balance with respect to the working fluid, a very small tank with a small mass and a small installation space can be provided. If the tank is even prepared only for temperature compensation and / or leakage compensation and / or piston volume equalization with respect to the working fluid, a very small tank with a particularly small mass and a particularly small space can be provided. Such a hydraulic cylinder device may additionally or alternatively be advantageously provided with a control unit. The control unit may be prepared for controlling and / or driving the piston movement, and it may be at least one control valve and / or a pump and / or an example electric pump drive and / or a tank - for example as described above - and / or an electrical circuit and / or a hydraulic circuit and / or a standardized interface and / or a control device, such as an ECU (electronic control unit) and / or a logic circuit. The control unit can generally be mechatronic, so at least two - preferably designed to match each other - have different components or components integrated with each other, which are selectable from a group, which includes, for example, mechanical, hydraulic, pneumatic, electrical, electronic, physical, chemical, and / or combustion engine components.

list of figures

• 1 prinzipiell in einem Längsschnitt einen Hydraulikzylinder gemäß einer ersten Ausführungsform der Erfindung, und
• 2 schematisch in einem Längsschnitt den Hydraulikzylinder gemäß einer zweiten Ausführungsform der Erfindung.

Two preferred embodiments of the invention are explained in more detail below with reference to schematic drawings. Show it:

• 1 in principle in a longitudinal section a hydraulic cylinder according to a first embodiment of the invention, and
• 2 schematically in a longitudinal section of the hydraulic cylinder according to a second embodiment of the invention.

Detailed Description of the Preferred Embodiments

The 1 shows in a schematic, longitudinal sectional view of a hydraulic cylinder 1 , The hydraulic cylinder 1 includes a cylinder tube 2 , a cladding tube 4 , two cylinder heads 6 and a pipeline 8th ,

The cylinder tube 2 extends along a longitudinal axis 10 , The cylinder tube 2 defines a cylinder chamber 12 , In the cylinder chamber 12 is a piston (not shown) along the longitudinal axis 10 absorbable and displaceable under the action and / or generating a pressure difference. The cladding tube 4 is coaxial with the cylinder tube 2 arranged so that there is a (not shown) longitudinal axis of the cladding tube 4 parallel with distance zero to the longitudinal axis 10 of the cylinder tube 2 extends. It surrounds the cladding tube 4 the cylinder tube 2 so that the cladding tube 4 with respect to the longitudinal axis 10 radially outside the cylinder tube 2 is provided, and the cladding tube 4 along the longitudinal axis 10 next to the cylinder tube 2 runs. The cylinder tube 2 and the cladding tube 4 together define a cooling chamber 14 , which as an annulus or annular space between the tubes 2 . 4 is formed.

The cylinder chamber 10 and the cooling chamber 14 are axially end by one of the cylinder heads 6 limited. The cylinder heads 6 close the chambers tightly 10 . 14 from. The chambers 10 . 14 are in terms of both the pipes 2 . 4 , the cylinder heads 6 as well as the connection not shown in detail between working pressure-tight, so that they act at least reliably sealing even when concerns an industrially usual working inside / outside pressure.

In the cooling chamber 14 is the pipeline 8th arranged. The pipeline 8th divides the cooling chamber 14 in two sections, namely a working fluid section 16 and a coolant portion 18 , There is a space in the pipeline 8th the coolant section 18 and is a room in the cooling chamber 14 outside the pipeline 8th the working fluid section 16 , The pipeline 8th includes along the longitudinal axis 10 three sections, namely a supply section 20 a heat exchange section 22 , which may also be referred to as a helix section, and another feed section 20 , The feeder sections 20 are prepared to the heat exchange section 22 to fluidly connect to a coolant source (not shown) and / or a coolant temperature sink (not shown). The heat exchange section 22 is in the cooling chamber 14 arranged. The heat exchange section 22 extends upwards along the longitudinal axis 10 , The heat exchange section 22 is about the longitudinal axis 10 wound around. The heat exchange section 22 is thus formed as a helix or a helix or a spiral.

The feeder sections 20 run through the cylinder heads 6 , Through the cylinder heads 6 Run also working fluid lines 24 , which are prepared to a working fluid in the cooling chamber 14 - More specifically, in the working fluid section 16 - to lead in and out. A working fluid stream 26 and a coolant flow 28 are by arrows in the 1 shown. The cooling chamber 14 with the pipeline 8th is in the present case connected as a countercurrent system, wherein the streams of working fluid flow 26 and coolant flow 28 be directed past each other with opposite flow direction.

Hereinafter, the second embodiment of the invention with reference to the 2 described. Parts corresponding to the first embodiment have the same reference number and will not be described again.

In contrast to the hydraulic cylinder 1 The first embodiment is not a pipeline in the second embodiment 6 in the cooling chamber 14 intended.

The 2 shows a hydraulic cylinder device 30 , which next to the hydraulic cylinder 1 with the cylinder tube 2 , the cladding tube 4 , the cylinder heads 6 , the cylinder chamber 12 and the cooling chamber 14 , another piston 32 and a control unit 34 includes. The piston 32 is in the cylinder tube 2 arranged and recorded. The hydraulic cylinder 1 , the hydraulic cylinder device 30 and the piston 32 are designed in differential construction, so that the piston 32 next to a piston bottom 36 two piston rods mounted opposite thereto 38 preferably having the same diameter. The control unit 34 includes, without further illustration, an electric motor that drives a pump and that is controlled together with valves.

The hydraulic cylinder device 30 is a closed or self-sufficient system. The piston bottom 36 divides the cylinder chamber 12 in two workrooms 40 , One of the cylinder heads 6 , here the left cylinder head 6 in the 2 , connects one of the workrooms 40 , here namely the neighboring, ie left working space 40 in the 2 , directly via a working fluid line 24 with a connection 42 , The same cylinder head 6 , here the left cylinder head 6 in the 2 , connects another port (not shown) via another working fluid line 24 with the cooling chamber 14 , The other cylinder head 6 , here the right cylinder head 6 in the 2 , connects the cooling chamber 14 with the other of the workrooms 40 , here namely the adjacent, so right working space 40 in the 2 , To the piston 32 from left to right in the 2 To relocate, the pump sucks a working fluid from the right working space 40 through the right cylinder head 6 , through the cooling chamber 14 and through the (not shown) connection in the control unit 34 , and from there, without interposition of a tank or the like, pushing on through the port 42 and the left cylinder head 6 in the left working space 40 , In this case, the working fluid is supplied with energy so that it heats up. At the same time, this gives the cooling chamber 14 flowing working fluid through the cladding tube 4 , which is formed for example of metal, and may be provided in a variant with cooling fins or the like, a heat energy to the environment from.

Thus disclosed is a hydraulic cylinder 1 with one extending along a longitudinal axis 10 extending cylinder tube 2 in which a piston 32 along the longitudinal axis 10 displaceable is receivable, and with a cladding tube 4 , which is at least parallel to the longitudinal axis 10 extends and the cylinder tube 2 at least partially surrounds, so between the cylinder tube 2 and the cladding tube 4 a cooling chamber 14 is formed, which can be flowed through by a working fluid and for cooling the cooling chamber 14 is prepared by passing working fluid.

Claims (12)

Hydraulic cylinder with a cylinder tube (2) extending along a longitudinal axis (10), in which a piston (32) can be received displaceably along the longitudinal axis (10), and with a jacket tube (4) which extends at least parallel to the longitudinal axis (10 ) and the cylinder tube (2) at least partially surrounds, so that between the cylinder tube (2) and the cladding tube (4) a cooling chamber (14) is formed, which can be flowed through by a working fluid and for cooling the working fluid flowing through the cooling chamber (14) prepared is. Hydraulic cylinder according to the Claim 1 , wherein the cylinder tube (2) and the jacket tube (4) are arranged approximately coaxially with each other, and / or wherein the cooling chamber (14) is formed as an annular space. Hydraulic cylinder according to one of Claims 1 to 2 , wherein the cooling chamber (14) is formed fluid-tight and / or working pressure-tight Hydraulic cylinder according to one of Claims 1 to 3 , wherein in the cylinder tube (2) by a piston (32) at least one working space (40) is definable, wherein the cooling chamber (14) with at least one working space (40) is at least fluid-connectable. Hydraulic cylinder according to one of Claims 1 to 4 , wherein each axially end a cylinder head (6) is provided which closes the cooling chamber (14) and / or the cylinder tube (2) each sealing. Hydraulic cylinder according to the Claim 5 in which a cylinder head (6) connects the cooling chamber (14) to a working space (40). Hydraulic cylinder according to one of Claims 5 to 6 in which a cylinder head (6) connects a working space (40) to a connection with interposition of the cooling chamber (14) and / or one or the cylinder head (6) connects a working space (40) to a connection (42). Hydraulic cylinder according to one of Claims 1 to 7 wherein the cooling chamber (14) is subdivided into a working fluid portion (16) and a coolant portion (18), and wherein the portions (16, 18) are fluid tight and / or working pressure-tightly separated, and / or wherein the coolant portion (18 ) is prepared for flowing through a coolant. Hydraulic cylinder according to the Claim 8 wherein the working fluid portion (16) and / or the coolant portion (18) is formed as a pipe (8) extending in the cooling chamber (14). Hydraulic cylinder according to the Claim 9 wherein the pipe (8) at least partially wound around the longitudinal axis (10) and / or formed along the longitudinal axis (10) rising. Hydraulic cylinder according to one of Claims 8 to 9 , wherein the pipe (8) is arranged in multiple layers. Hydraulikzylindervorrichung with a hydraulic cylinder (1) according to one of the preceding Claims and with a in the cylinder tube (2) recorded piston (32) and / or with a working fluid pump and / or with a tank, which is prepared for temperature compensation and / or leakage compensation and / or piston rod volume compensation with respect to the working fluid, and / or with a Control unit (34).

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