JP4862077B2 - Valve devices for hydraulic machines - Google Patents

Description

  The invention relates to a valve device according to the preamble of claim 1 or 3.

  Conventional valve devices include three components of a hydraulic machine that are arranged in contact with each other at their respective installation positions. That is, the valve receiving portion and the attachment that are adjacent to each other by the contact surfaces facing each other, and the end facing the attachment are arranged in the region of the joint portion formed by the two contact surfaces of the valve receiving portion and the attachment. And a valve stem guide inserted into the receiving hole of the valve receiving portion. In this case, the valve stem guide is separated from the attachment by a first cross section of the receiving hole and a second cross section adjacent thereto in the valve stem guide along its center line, which is also the center line of the receiving hole. And is defined and arranged in the direction of the attachment by a third cross section of the valve stem guide and a fourth cross section of the attachment.

  This axial mating of the valve stem guide between the valve seat and the attachment is pre-adjusted by a motion fit to ensure that the valve stem guide fits between the valve seat and the attachment during assembly. To be produced. Thanks to this movement fit, it is ensured that the valve seats and attachments are adjacent to each other by their respective contact surfaces, which is essential for a stable impervious installation position.

  In practice, however, the valve stem guide, in the mode of operation of the hydraulic machine, due to its axial installation play causes a slight longitudinal movement due to pressure fluctuations of the hydraulic medium or machine vibrations, which When the ring seal around the valve stem guide is disposed as an axial seal between the valve stem guide and the valve receiving portion, it may cause wear due to sliding movement. Also, considerable stress is present as a result of compression when the radial seal is disposed in the region of the junction between the valve stem guide and the attachment. In the case of radial seals, the associated seal ring is acted upon alternately by a slight axial movement of the valve stem guide with respect to its axial compression, i.e. the compression increases or decreases alternately as a result of the axial movement. To do. Wear in the case of this stress is clearly low, but in the case of permanent loads it still leads to a negative effect on the radial seal and its life.

  However, on the one hand, even if there is no axial seal between the valve stem guide and the valve receiver and / or no radial seal between the valve stem guide and the attachment, In the case of pressure fluctuations of rapidly changing magnitude, so-called valve chattering of the valve device can occur and the valve chattering is increased by an additional oscillating movement as the valve body concerned.

  The object underlying the present invention is to improve the valve device, in particular to extend the life of the axial seal and / or radial seal of the valve device. A further object is to make the manufacture of the valve device simpler and more cost effective. The sealing of the valve stem guide in the area of the joint, in particular between it and the attachment, is further improved.

  This object is achieved by the features of claim 1 or claim 3. Advantageous results of the invention are described in the dependent claims.

  4. A valve device according to the invention as claimed in claim 1 or 3, wherein the valve stem guide and / or attachment has an axial deformation zone which is compressed in each case in that region which lies opposite the valve stem guide. It is compressed by the clamping force. This results in a free seating of the valve stem guide between the valve seat and the attachment, thereby avoiding axial movement, for example vibration, of the valve stem guide in the operating mode of the hydraulic machine. This also means that the axial ring seal and / or radial ring seal of the valve stem guide are not adversely affected and the life is extended.

  Furthermore, the results according to the invention lead to an improved radial seal between the valve stem guide and the attachment. In this case, due to the deformation, a special surface fit of the abutting surfaces of the valve stem guide and the attachment occurs, this fit further improving the radial seal.

  Within the scope of the present invention, at least one deformation zone may be arranged in the valve stem guide and / or in the region of the attachment that is opposite the valve stem guide. This depends on the strength of the material of the valve stem guide and attachment. The deformation zone according to the invention is formed under a clamping force at a part having a lower material strength. If the valve stem guide and the attachment are made of the same material, the deformation area is formed in the area where both of these parts abut one another.

  According to the invention, the clamping force is generated by a clamping device associated with a hydraulic machine. In this case, the aforementioned cross-sectional dimensions depending on the existing clamping force are required in such a way that the local deformation according to the invention of the deformation zone is achieved while the valve seat and the attachment are assembled and clamped against each other. Is particularly advantageous. The associated clamping device is preferably formed by a screw connection between the valve seat and the attachment. With such a screw connection, the effect according to the invention is inevitably achieved during the assembly of the hydraulic machine, ie during the standard screw connection of the attachment to the valve seat.

  Compression of the deformation zone in the elastic region has the advantage that the deformation zone can be expanded and recompressed after disassembly and reassembly, for example after repair or maintenance, and the effect according to the invention can be completely reequipped. Have.

  In the case of compression and deformation in the plastic zone of the axial distance between its axial support surfaces, the valve device can be reused after disassembly due to the residual elasticity of the deformation zone.

  A further advantage of the results according to the invention is that the improved radial seal described above is very insensitive, especially to the high pressure loads of the supplied hydraulic fluid. For this reason, the results according to the invention are particularly suitable for valve devices in high pressure applications.

  Furthermore, the results according to the invention are particularly suitable for axial piston machines in which the piston movement in the mode of operation causes the vibration mentioned in the beginning of the valve stem guide and / or forcing it under the simultaneous action of pressure fluctuations. .

  Hereinafter, a valve device according to the present invention will be described with reference to embodiments and simplified drawings.

  The valve device generally indicated by 1 includes three main parts: a valve receiver 2, an attachment 3 and a valve stem guide 4, and the valve stem guide is spatially located between the valve receiver 2 and the attachment 3. And is installed in the receiving hole 5 with a slight movement gap from the contact surface 2a of the valve receiving portion 2 facing the attachment 3. In the partially assembled state of the valve device 1 shown in FIG. 1, the contact surface 3a of the attachment 3 facing the valve receiving portion is not in contact with the contact surface 2a but is described in more detail. Located at directional distance a. The attachment 3 can be connected to the valve receptacle 2 by means of a clamping device S, which is indicated by two arrow lines, preferably formed by a screw connection 6 consisting of a plurality of mutually spaced screws. The screw penetrates into the screw holes of the attachment 3 and the valve receiver 2 and is indicated by a dotted line. The clamping force that can be generated by the clamping device S is indicated by an axial arrow.

  The receiving hole 5 has a first cross section 8 at an axial distance b from the contact surface 2a, which is composed of an enlarged hole portion 5a open at the contact surface 2a and a reduced hole portion 5b extending from the hole portion 5a. Formed by the shoulder surface between. The valve stem guide 4 is locked to the first cross section 8 by the second cross section 9 and the latter is likewise arranged by a stepped surface between the enlarged guide body part 4b and the reduced guide body part 4c. The enlarged guide body portion 4b is fitted into the enlarged hole portion 5a with a slight movement gap. Since the reduction guide main body portion 4c is smaller than the reduction hole portion 5b, an annular flow path exists between them, which forms a flow path portion 11a described later.

  The valve stem guide 4 has a third cross-section 12 at its end that faces the attachment 3 and is formed by its end face, so that the guide is the axis of the attachment 3 that is part of the contact surface 3a. Lock to the fourth cross section 13 facing in the direction. These cross-sections 12, 13 are annular surfaces that abut one another, which will be described in more detail.

  In the embodiment, the valve 14 of the valve device 1 is configured in the valve stem guide 4 such that a prefabricated valve unit 15 that can be assembled by being inserted into the receiving hole 5 is formed together with the valve stem guide 4.

  In the embodiment, the valve 14 is a check valve, and the valve body 14 a is elastically preloaded against the edge of the valve opening 17 by the force and / or pressure of fluid flow. This elastic preload can additionally be further aided by the action of a spring.

  In the embodiment, the valve body 14 a is disposed at the opposite end of the valve stem guide 4 with respect to the enlarged guide main body portion 4 b and is formed by a tapered valve head 14 b, and the latter is the edge of the valve opening 17. The flow path portion 11b extends in a direction away from the attachment 3 from there. The flow path part 18a is a part of the hydraulic line 11, which continues as an annular flow path 11a, surrounds the reduced guide body portion 4c, extends to the valve stem guide 4 via the radial flow path 11c, It continues in the axial direction as a longitudinal flow path portion 11d formed therein, and opens at the end face related to the valve stem guide 4, and also faces the axial direction of the attachment 3 opened at the contact surface 3a. Continue to 11e.

  In the region of the valve unit 15 and / or the valve stem guide 4 and / or its valve stem guide body, a filter 23 is preferably installed, which in the embodiment is seated on the channel 11d.

  The valve stem guide 4 is sealed to the valve device 1 by an axial ring seal 24 and / or a radial ring seal 25. The axial ring seal 24 is disposed between the enlarged guide body portion 4b and the wall of the hole portion 5a and is formed by one or two seal rings 24a, 24b, which are preferably side portions of the valve stem guide 4. It sits in an annular groove 24c disposed on the surface.

  The radial ring seal 25 is connected to the valve stem guide 4 and the attachment 3 in the region of the joint 26 formed by the contact surfaces 2a and 3a between the attachment 3 on the one hand and the valve receiver 2 and the valve stem guide 4 on the other hand. It is arrange | positioned toward the front between.

  The radial ring seal 25 is formed by a seal ring 25a, for example an O-ring, which is preferably disposed in an outwardly opening annular groove 25b, which is preferably circular with the dimensions indicated by c. Of the valve stem guide 4 having an outer cross section, preferably surrounding the coaxial annular portion 4d.

  The object of the present invention is to improve the sealing between the valve stem guide 4 and the attachment 3. This is achieved by a clamping force which is oriented transversely at the joint 26 between the parts and preloads them against each other in the region of the respective cross section 12,13. In this case, the surface pressure on the cross-sections 12, 13 is arranged in the deformation zone 30 or in the valve stem guide arranged in the region of the attachment 3 shown in FIG. 2 and facing the valve stem guide 4. (FIG. 3) The deformation zone 30 is large enough to be deformed by compression, ie elastically deformed, or even plastically deformed.

  This is because the axial distance between the cross-section 9 of the valve stem guide 4 and its end facing the attachment 3 with respect to the distance b between the shoulder surface 8 of the valve receiver 2 and its contact surface 2a. Is prefabricated with an oversize corresponding to the distance a (FIG. 1) or the cross section 13 of the attachment 3 is prefabricated with a protrusion corresponding to the distance a with respect to its contact surface 3a (not shown) To achieve this.

  In the embodiment, the valve stem guide 4 is configured with this oversize, as shown in FIG. 1, the attachment 3 has a continuous planar contact surface 3a, and the annular cross section 13 is one of its parts. Part.

  Due to this prefabricated oversize, when the valve receiver 2 and the attachment 3 are clamped together by the clamping device S in the final assembly position according to FIG. 2 where the contact surfaces 2a, 3a are in contact with each other. The cross sections 12, 13 are pressed against each other. This leads in each case to a deformation zone 30 which has been compressed and deformed in the region of the relevant cross section 12, 13, which can also be arranged in both parts. The position of the deformation zone 30 in one part and / or the other part is determined by the strength of the material of the valve stem guide 4 and the attachment 3. The deformation zone 30 is formed in a portion with a lower material strength. If both parts are made of the same material, the deformation zone 30 may occur in the region of the cross section 12, 13 of both parts. In the current embodiment, the material of the attachment 3 is more flexible than the material of the valve stem guide 4. For this reason, the deformation zone 30 is formed in the region of the cross section 13 and hence in the attachment 3 during the integral clamping operation.

  The resistance applied to the clamping force is determined by the size of the cross sections 12 and 13. If the clamping force of the existing clamping device S has to be utilized to cause deformation in the deformation zone 30, the size of the cross sections 12, 13 must be adapted to the existing lower clamping force. This can be determined by adapting the cross-sectional dimensions and / or diameters d and / or e of the annular part 4d and / or the channel part 11e.

  Depending on the size of the oversize corresponding to the distance a, it is possible to determine whether the deformation zone 30 will be elastically or plastically deformed and / or whether it is actually deformed. In other words, the larger the selected oversize, the greater the deformation and / or compression in the deformation zone 30.

  Therefore, in the result of the present invention, not only is the valve stem guide 4 disposed in the axially non-displaceable manner in the receiving hole 5, but also the sealing between the valve stem guide 4 and the attachment 3 is improved, And / or a radially effective ring seal 31 (FIG. 2) is created. The greater the clamping force and the resulting deformation, the greater the impermeability of this seal. As a result of the deformation, the cross-sections 12, 13 come into specially adapted surface contact with each other, so that the impermeability is particularly great.

  Thus, within the scope of the present invention, this radial ring seal 31 based on the surface pressure of the abutting cross sections 12, 13 can be replaced by a radial ring seal 25. The arrangement of both radial ring seals 25, 31 is particularly advantageous when the flow path 11 is a high pressure flow path through which the hydraulic medium is transported at high pressure in the operating mode. The radial ring seal 31 is particularly capable of undertaking such pressures, in particular high pressure, and thus can reduce the burden on the radially outer ring seal 25 and extend its life, In this case, the life of the ring seal 31 is also extremely long.

  In the embodiment according to FIG. 3, in which the same or corresponding parts are given the same reference characters and the valve device 1 is illustrated in the final assembled state according to FIG. 1, the annular part 4d or at least the end of the annular part 4d is , Formed and / or replaced by an additional component, i.e. ring 4e, which is arranged in the valve stem guide body, the latter being shortened with respect to its axial dimension and surrounding the channel part 11d. ing. The side surface of the ring 4e can be adapted to the internal dimensions of the seal ring 25a in such a way as to form a seat for the seal ring 25a.

  The advantage of this result is that the ring 4e can be made of a material that is independent of the material of the other parts of the valve stem body and can be chosen to be harder or softer than the material of the attachment 3. In the latter case, the deformation zone 30 occurs in the region of the cross section 12, i.e. in the contact region of the ring 4e.

  The invention is not limited to the illustrated embodiment. For example, instead of an O-ring, any other configuration of an elastic seal can be used. The elastic seal can be made of rubber or a synthetic polymer material. All of the features described or illustrated can be combined with each other in any desired manner within the scope of the invention.

1 shows a valve device according to the invention in an intermediate assembly position in an axial section. The valve device in the final assembly position is shown. Fig. 4 shows the valve device in a modified result in the final assembly position.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Valve apparatus 2 Valve receiving part 2a Contact surface 3 Attachment 3a Contact surface 4 Valve stem guide 5 Receiving hole S Tightening device 6 Screw connection part 8, 9 Cross section 11 Flow path 12, 13 Cross section 14 Valve 15 Valve unit 17 Valve Opening 18a Flow path 23 Filter 24 Axial ring seal 25 Radial ring seal 26 Joint 30 Deformation area 31 Ring seal

Claims (12)

A valve device (1) for a hydraulic machine, in particular an axial piston machine,
A valve receiver (2) and an attachment (3), which are in contact with each other by mutually facing contact surfaces (2a, 3a),
A valve stem guide (4) arranged in a receiving hole (5) which is arranged in the valve receiving part (2) and which opens toward the attachment (3);
And a flow path (11) extending longitudinally in the valve stem guide (4), exiting at an end face facing the attachment (3), and further extending into the attachment (3),
A radial ring seal (25) surrounding the flow path (11) is disposed between the valve stem guide (4) and the attachment (3),
The compressed axial deformation zone (30) provided in the region of the valve stem guide (4) faces the attachment (3) and / or is compressed in the region of the attachment (3) The valve device characterized in that the axial deformation zone (30) faces the stem guide (4) and is compressed by a clamping force for clamping the valve stem guide (4) and the attachment (3) together. The valve stem guide (4) is supported by the cross section (8) of the valve receiver (2) in the direction away from the attachment (3), and is tightened by the clamping device (S). 3. The valve device according to claim 1, wherein 3) are preloaded against each other . A valve device (1) for a hydraulic machine, in particular an axial piston machine,
A valve receiver (2) and an attachment (3), which are in contact with each other by mutually facing contact surfaces (2a, 3a),
A valve stem guide (4) arranged in a receiving hole (5) which is arranged in the valve receiving part (2) and which opens toward the attachment (3);
And a flow path (11) extending in the longitudinal direction in the valve stem guide (4), exiting at an end face facing the attachment (3), and further extending to the attachment (3),
The valve stem guide (4) is supported by the cross section (8) of the valve receiver (2) in a direction away from the attachment (3). The valve receiver (2) and the attachment (3) S) are tightened together,
The compressed axial deformation zone (30) provided in the region of the valve stem guide (4) faces the attachment (3) and / or is compressed in the region of the attachment (3) The valve device characterized in that the axial deformation zone (30) faces the stem guide (4) and is compressed by a clamping force for clamping the valve stem guide (4) and the attachment (3) together.   The deformation zone (30) is either elastically deformed in the elastic region of the material or plastically deformed beyond the elastic limit of the material. The valve device according to item.   The valve stem guide (4) is disposed between the axial ring seal (24) disposed around the valve stem guide (4) and / or between the valve stem guide (4) and the attachment (3). 5. The valve device according to claim 3, wherein the valve device is sealed by a radial ring seal (25) surrounding the flow path (11).   The fastening device (S) is formed by a screw connection (6) between the valve receiver (2) and the attachment (3). Valve device. The valve stem guide (4) and attachment in the region of the joint (26) formed by the contact surface (2a, 3a) between the attachment (3) and the valve receiver (2) and the valve stem guide (4) 7. A valve device according to any one of the preceding claims, characterized in that a radial ring seal (25) is provided between (3). The radial dimension of the deformation zone (30) is the cross-sectional dimension (d) outside the annular part (4d) on which the radial ring seal (25) is seated and the channel part (11e) connected to the attachment (3). The valve device according to claim 7, wherein the valve device is determined by a cross-sectional dimension (e).   The attachment (3) is made of a softer material than the valve stem guide (4), and the deformation area (30) is disposed in the region of the attachment (3) facing the valve stem guide (4). The valve device according to any one of claims 1 to 8, wherein:   The annular part (4d) or the end part of the annular part (4d) is a ring (4e) provided on the valve stem guide (4) and surrounding the flow path part (11d). The valve device according to any one of 9. The receiving hole (5) has an enlarged hole portion (5a) opened on the contact surface (2a) side and an axial width from the hole portion (5a) at a distance b in the axial direction from the contact surface (2a), and becomes narrower inward in the axial direction. A first cross section (8) formed on the shoulder between the extending reduced hole portion (5b) is provided, is opposed to the first cross section (8) and is reduced with the enlarged guide portion (4b). In the valve stem guide (4) having the second cross section (9) positioned between the guide portion (4c), the second cross section (9) leans against the first cross section (8). The valve device according to any one of claims 2 to 10 , wherein: A valve opening (17) is disposed at the bottom of the receiving hole, and the valve body (14a) interacts therewith so that the valve body can be displaced in the axial direction in the valve stem guide (4). 12. The valve device according to claim 1 , wherein the valve opening is pre-pressurized by a flow force and / or pressure.

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