CN113994103A

CN113994103A - Hydraulic control block and servo hydraulic shaft with same

Info

Publication number: CN113994103A
Application number: CN202080046558.7A
Authority: CN
Inventors: M·伦佩尔; J·施瓦克
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2019-06-27
Filing date: 2020-06-18
Publication date: 2022-01-28
Anticipated expiration: 2040-06-18
Also published as: DE102019209322A1; WO2020260128A1; CN113994103B

Abstract

The application discloses a hydraulic control block for a servo hydraulic shaft, in particular a linear shaft, having at least a hydraulic connection for a hydraulic actuator for hydraulically connecting the shaft and having a first chamber in which a hydraulic machine or at least a drive train assembly of the hydraulic machine can be received at least partially for the supply of pressure medium to the actuator. A servo hydraulic shaft with the hydraulic control block is also disclosed.

Description

Hydraulic control block and servo hydraulic shaft with same

Technical Field

The present invention relates to a hydraulic control block according to the preamble of claim 1 and to a servo hydraulic shaft with said control block according to claim 14.

Background

The servo hydraulic shaft, in particular the linear shaft, is in particular in a closed circuit and, with a small oil quantity, allows the force development of a hydraulic actuator, for example a hydraulic cylinder, to be matched to the dynamics, accuracy and flexible crossability of an electrically actuable actuator, for example a servo motor. It can be squeezed, engaged or closed with a large axial force and positioned at the same time in the micrometer range. Generally involving a linear motion. A solution in a semi-closed loop is also possible.

The applicant's data page RD 08137/2018-02 shows a servo hydraulic spindle of this type. The compact shaft has a servo actuator, a hydraulic cylinder, a hydraulic accumulator and control elements such as, for example, valves, and power electronics.

In particular in the case of small available installation spaces, a compact, installation-space-optimized solution is important. In addition to the disassembled form of the shaft, in which the mentioned components are connected to the central hydraulic control block by means of hoses, lines, pipes, compact forms with direct mechanical and hydraulic and electrical connections to the control block are therefore also possible. There is a constant desire to improve the compact design with regard to the use of installation space and energy efficiency.

Disclosure of Invention

In contrast, the object of the present invention is to provide a hydraulic control block for a servo hydraulic shaft, which reduces the installation space requirement of the shaft while the energy efficiency remains the same or is improved. Furthermore, the object of the invention is to provide a servo hydraulic spindle having the hydraulic control block.

The first task is solved by a hydraulic control block having the features of claim 1, and the second task is solved by a servo hydraulic shaft having the features of claim 14.

Advantageous developments of the hydraulic control block are described in the respective dependent claims.

The hydraulic control block for a servo hydraulic shaft, in particular for a linear shaft, has at least one hydraulic connection for a hydraulic actuator, in particular a hydraulic cylinder, which is hydraulically connected to the shaft. Preferably, the hydraulic control block further has a mechanical interface for mechanically connecting the actuator. Preferably, a mechanical interface for connecting an electrical actuator, in particular a servo actuator, is also provided. According to a first variant of the pressure medium supply for the hydraulic actuator, the hydraulic machine or at least the drive train assembly of the hydraulic machine can be accommodated at least partially in the (first) chamber of the control block. The hydraulic machine can also be flanged or cased onto the block. According to the invention, a (second) chamber is provided in which a filter element for filtering the pressure medium can be received or accommodated at least in sections.

Since the filter or filter element is now no longer arranged outside but in the hydraulic component of the control block, which is already present in the center, a servo hydraulic shaft with a smaller installation space requirement can be realized. A separate filter housing is omitted, since the filter housing is now formed by the control block. Furthermore, with this arrangement, the filter can be fed in the vicinity of the hydraulic pump via very short inlets and outlets. This reduces the pressure loss. Overall, the installation space requirement of the shaft is reduced while the energy efficiency remains the same or is improved.

The cylinder can be cased, flanged or integrated. The low pressure can be supplied by an additional set (semi-closed circuit).

The control block preferably has a switching valve and, in addition, a relief valve, so that different drive modes of the hydraulic and/or electric actuators can be switched and protected.

The filter element is preferably a filter cartridge.

The opening of the second chamber is arranged at the outer surface of the control block in an easily accessible manner for rapid replacement of the filter element.

Preferably, the inlet and outlet of the second chamber are fluidly connected to the suction and pressure ports of the first chamber or the suction and pressure sides of the hydraulic machine, respectively, by passages configured in the control block.

The filter can also be integrated in the low-pressure circuit before the hydraulic machine.

Preferably, the second chamber is closed off towards the outside by a closing element, in particular a closing screw.

In a refinement, the chambers are spaced apart along the extension direction of the control piece and are arranged with at least partial overlap along a transverse direction relative to the extension direction of the control piece, whereby the control piece is constructed less in both directions.

In a space-saving development, the outer circumferential section is formed by a largely constant offset relative to the second chamber or its inner circumference.

One development is to realize the chamber partially or entirely by casting.

The control block is preferably cast, wherein at least one of the chambers is shaped by means of a casting core. Additionally, the chamber can be drilled or milled to reach its final dimensions.

In a development, the second chamber is designed in such a way that the filter, the filter element, can be supplied at different positions, whereby in particular an inlet optimization or a flow path optimization can be achieved.

In a development, a pressure medium flow path, in particular an inflow channel, is provided which connects the first or hydraulic machine with the second chamber. The pressure medium flow path has an inlet opening in the inner circumferential surface of the second chamber.

In one refinement, the inner circumferential surface extends circumferentially around a mounting axis for the second chamber of the filter element. Cylindrical chambers are also possible.

The pressure medium flow path advantageously has a direction component tangential to the inner circumferential surface at least at the inlet opening.

The inlet opening can optionally be implemented by a casting core in an even more flow-optimized manner.

In order to improve the separation, reduce the pressure loss caused by the filter element and increase the service life thereof, in a development the inner circumferential surface of the second chamber has a cutout which extends helically around the installation axis of the second chamber. This slit imparts a cyclonic flow pattern ("vortex") to the pressure medium, which causes a separation at the bottom of the second chamber that is independent of the filtering action of the filter element.

In one refinement, the incision starts directly at the inlet opening of the second chamber or in a manner spaced apart from the inlet opening.

In one refinement, the cutout extends circumferentially or at least once completely circumferentially around the insertion axis.

The cross-sectional shape which is advantageous in terms of flow technology is a truncated semicircular or elliptical cross section of the cutout.

The depth-to-width ratio of the cross section of the incision is preferably between 1:10 and 1:5, in particular about 1: 7.

The spiral shape can be milled or realized by additional components.

In a variant, the installation axes of the first chamber for the hydraulic machine or the power transmission assembly and of the second chamber for the filter element are parallel, transverse or perpendicular to one another.

The servo hydraulic shaft has a hydraulic control block constructed in accordance with at least one aspect of the foregoing description. Furthermore, the servo hydraulic shaft has at least a hydraulic actuator hydraulically connected thereto, a hydraulic machine for pressure medium supply thereof, which is received in the first chamber, or a power transmission assembly thereof, and a filter element for filtering the pressure medium, which is received in the second chamber.

Since the filter or filter element is now no longer arranged outside but in the hydraulic component of the center of the control block, which is present anyway, the servo hydraulic shaft has a smaller installation space requirement. A separate filter housing, which would otherwise be necessary, is dispensed with. The filter housing is now formed by a control block. Furthermore, with this arrangement, the filter is fed and unloaded near the hydraulic pump via very short inlets and outlets. This reduces the pressure loss. Overall, the installation space requirement of the shaft is reduced while the energy efficiency remains the same or is improved.

Drawings

In the drawing, various embodiments of a hydraulic control block according to the invention and a servo hydraulic shaft according to the invention are shown. The invention will now be explained more with the aid of the figures of these drawings.

Wherein:

figure 1 shows a side view of a servo hydraulic shaft according to the invention according to an embodiment,

figure 2 shows a partially transparent bottom view of the hydraulic control block according to the invention of the servo hydraulic shaft according to figure 1,

figure 3 shows the hydraulic control block according to figure 2 in a partial perspective view,

figure 4 shows the hydraulic control block according to figures 2 and 3 in a partially transparent top view,

FIG. 5 shows the area of the filter receptacle of the hydraulic control block according to the previous figures in a partially transparent side view, and

fig. 6 shows the filter receptacle according to fig. 5 with the inserted filter element in a longitudinal section.

Detailed Description

The servo hydraulic shaft 1 has according to fig. 1 a hydraulic actuator 2 in the form of a hydraulic cylinder or hydraulic cylinder, by means of which hydraulic actuator 2 an axial force can be applied to a tool or workpiece for pressing, engaging, closing and/or positioning, the servo hydraulic shaft 1 furthermore having an electric actuator 4 in the form of a servo motor and supplied by power electronics 6, a hydraulic accumulator 8 for storing and recovering the hydrostatic energy of the hydraulic cylinder 2, and a hydraulic control block 10, which hydraulic control block 10 is arranged centrally, and the mentioned components 2, 4 and 8 and a further valve control device 12 for controlling the hydraulic cylinder 2 are arranged and/or fixed and/or flanged and/or cased onto the hydraulic control block 10. The compact design shown in fig. 1 is particularly space-saving, but can also be designed partially or completely in an exploded arrangement. In this case, in particular the hydraulic assemblies 2 and 8 mentioned (only 2 is also possible) are removed from the control block 10 and connected to hydraulic lines or hoses.

The pressure medium of the hydraulic cylinder 2 used during operation flows in a closed hydraulic circuit which is essentially formed by the control block 10, the hydraulic pump (not shown) received therein and the hydraulic cylinder 2. The pressure medium is continuously filtered. The servo hydraulic shaft 1 therefore also has a hydraulic filter with a filter element (not shown in fig. 1) which is integrated according to the invention into the hydraulic control block 10, which is shown in more detail with the aid of the following figures. The low-pressure circuit can also be supplied by the aggregate.

Fig. 2 to 4 show a top view, a perspective view and a bottom view, respectively, of the control block 10 according to fig. 1. The illustration is chosen partly transparent, wherein the outer wall of the control block 10 allows to see into its interior, while the chambers, pressure medium channels and other recesses in the control block 10 are shown as opaque walls. Fig. 3 in particular shows a second chamber 14 designed as a filter element receptacle, into which second chamber 14 a filter element can be inserted.

By virtue of the arrangement of the filter element or filter integrated in the control block 10, a more direct hydraulic actuation and pressure medium application of the filter element of the servo hydraulic shaft 1 can be achieved and at the same time a more compact design thereof can be achieved. This results in a smaller installation space requirement and in a more compact appearance of the servo hydraulic spindle 1, since the filter is now "invisibly" arranged in the control block 10.

Furthermore, a shortening of the inlet to and outlet from the filter element is provided by this integration, so that the length of the pressure medium pipe or pressure medium hose to be installed can be reduced. This reduction of the pressure-elastic components improves the controllability of the shaft 1 and furthermore reduces the length-dependent pressure losses along the relevant flow path.

According to fig. 2, the hydraulic control block has a longitudinal axis 18, which longitudinal axis 18 extends transversely to the longitudinal axis 16 of the hydraulic cylinder 2 according to fig. 1, and a plane of symmetry extends through the longitudinal axis 18, which relates at least to the lateral outer circumference of the hydraulic control block 10. The axis of extension 21 of the receptacle 14 is arranged in this plane of symmetry.

The control block 10 has raised connection surfaces 24 on its longitudinal or

lateral sides

20, 22 arranged symmetrically with respect to the plane of symmetry for a compact and space-saving connection of the valves of the valve device 12 according to fig. 1. At the upper side 26 of the control block 10, which is partially parallel to the lower side 28, a recess 30 is provided for receiving a hydraulic pump (not shown) or at least a power transmission component of the hydraulic pump.

According to fig. 4, the recess 30 or the first chamber 30 has a high-pressure connection 34 and a further high-pressure connection 36 at its bottom 32, since pressure can build up in a closed circuit in both pump rotational directions. The high-pressure connections 34, 36 are connected via a pressure medium channel, not described further, which is formed in the control block 10, to a connection for supplying the hydraulic cylinder 2 with pressure medium.

In order to save even more installation space, the outer circumferential surface of the control block 10 according to fig. 3 at the lower side 28 is not parallel to the upper side 26 in the region of the second chamber 14, but only has an offset d with respect to the inner circumferential surface 38 of the second chamber 14.

The control piece 10 is at least partially formed narrower on both sides of the extended second chamber 14, i.e. in the direction of the side faces 20, 22, than the remaining section of the control piece.

At least one connection for a hydraulic assembly, in particular, is provided at least one transition of the narrower section to the remaining section, in particular at a shoulder of the control block 10 formed there.

For the same purpose of saving installation space, the control block 10 has a narrowing or

bevel

42, 44 at the upper side 26 and the lower side 28 of the end section 40 arranged diametrically opposite the second chamber 14 or the filter receptacle 14.

The same applies to the underside 28, which extends in the lateral longitudinal direction at the middle section of the control block 10, as shown in fig. 3. Here, too, a ramp is provided at the hydraulic control block 10.

The flow profile of the second chamber 14 and the pressure medium to be filtered will now be described with reference to fig. 5. The course of the flow from the inlet a to the outlet F is sketched in fig. 5 and 6. Fig. 6 shows a longitudinal section through the mentioned symmetry plane of the control block 10 and thus also through the extension axis 21 of the second chamber 14, according to fig. 6, the inlet opening 46 of the inlet a being arranged in the lateral bottom region B of the second chamber 14. At the inlet opening 46, the pressure medium flow path of the inflowing pressure medium, in particular the inflow channel merging therein, has a direction component tangential to the inner circumferential surface 38. Preferably, the inner circumferential surface of the inlet opening 46 is tangentially turned into the inner circumferential surface 38.

Preferably, the inlet opening 46 is designed such that in its region the pressure medium flow path is directed into an annular space 48 formed between the filter element 50 and the inner circumferential surface 38. In this way, the filter element 50 is mechanically protected, since it is not directly acted upon by a radial flow. This results in an increased durability of the filter element 50 and an extended maintenance interval. Smaller loads can also be used for smaller dimensions of the filter element 50, which in turn enables a saving in installation space.

In the inner circumferential surface 38, a cutout recess 52 extending helically around the extension or insertion axis 21 is connected to the inlet opening 46. As can be seen from fig. 6, the cutout recess 52 has a semi-elliptical cross section which is largely truncated in the exemplary embodiment, as can be seen better in the regions C and D. The three-dimensional, helical extension of this cut 52 is evident when viewing fig. 5.

From the opening region B, the pressure medium flows through the annular space 48 along the cut-out 52, also outside the cut-out 52 due to turbulence and undesired flow guidance, passes through the cross section C and the cross section D and is deflected there in the radial direction onto the filter element 50. There, the pressure medium flows through the filter element 50 and into the central outlet pipe 54. On the (preferably left) side leading to the outlet opening, there is an adapter which centers the element. The pressure medium continues to flow up to a cross section F, which represents the outlet on the bottom side of the filter element 50. By means of the spiral flow, a cyclonic separating effect is superimposed on the filter effect and the separation of impurities is further improved.

The penetration zone E extends over the entire filter element. The spiral shape causes a revolution around the filter element.

A hydraulic control block for a servo hydraulic shaft is disclosed having a filter or filter element received in the control block or at least having a chamber provided therefor.

Furthermore, a servo hydraulic shaft with the hydraulic control block is disclosed.

Claims

1. Hydraulic control block for a servo hydraulic shaft (1), in particular a linear shaft, having at least a hydraulic connection for hydraulically connecting a hydraulic actuator (2) of the shaft (1) and having a chamber (30), in which chamber (30) a hydraulic machine or at least a power transmission assembly of the hydraulic machine can be received at least partially for the pressure medium supply of the actuator (2), or wherein the hydraulic machine is flanged or cased, characterized by a preferably second chamber (14), in which second chamber (14) a filter element (50) for filtering the pressure medium can be received or received at least partially.

2. A control block as claimed in claim 1, wherein the chambers (14, 30) are spaced apart along the extension direction of the control block (10) and are arranged with at least partial overlap along a transverse direction (18) with respect to the extension direction of the control block (10).

3. Control block according to claim 1 or 2, having a peripheral surface section with a particularly mainly constant offset (d) relative to the preferably second chamber (14).

4. Control block according to any of claims 1 to 3, which is cast, wherein at least one of the chambers (14, 30) is shaped and/or drilled by means of a casting core.

5. Control block according to one of the preceding claims, having a pressure medium flow path, in particular an inflow channel (a), connectable or connected to the hydraulic machine, which has an inlet opening (46) in preferably the inner circumferential surface (38) of the second chamber (14).

6. A control block as claimed in claim 5, wherein the inner circumferential surface (38) extends circumferentially around a mounting axis (21) for a preferably second chamber (14) of the filter element (50).

7. Control block according to claim 5 or 6, wherein the pressure medium flow path has a direction component tangential to the inner circumferential surface (38) at least at the inlet opening (46).

8. A control block as claimed in any preceding claim, wherein the inner circumferential surface (38) of the preferably second chamber (14) has a cut-out (52), the cut-out (52) extending helically around the insertion axis (21) of the preferably second chamber (14).

9. Control block according to claim 8, wherein the cut-out (52) starts from an inlet opening (46) or starts spaced apart from the inlet opening (46).

10. Control block according to claim 8 or 9, wherein the cut-out (52) extends circumferentially or at least once completely circumferentially around the mounting axis (21).

11. The control block according to any of claims 8 to 10, wherein the cut-out (52) has a truncated semi-circular or elliptical cross-section (C, D).

12. Control block according to any of claims 8 to 11, wherein the cut-out (52) has a depth to width ratio of between 1:10 and 1:5, in particular 1: 7.

13. Control block according to at least claim 6, wherein the axis of introduction of the first chamber (30) for the hydraulic machine or the power transmission assembly is parallel or consecutive or in line or transverse or perpendicular to the axis of introduction (21) of the second chamber (14) for the filter element (50).

14. A servo hydraulic shaft having a hydraulic control block (10) constructed according to one of the preceding claims and having at least a hydraulic actuator (2) hydraulically connected at the hydraulic control block (10), a hydraulic machine for pressure medium supply of the hydraulic actuator (2) and a filter element (50) for filtering the pressure medium, the filter element (50) being received in a preferably second chamber (14).