Device for volume compensation

Abstract

The utility model relates to equipment for volume compensation, which at least comprises an equipment shell (10) and a compensation element (12) capable of being movably guided in the equipment shell, the compensation element can be supported on an energy accumulator (14) in a manner of being loaded by fluid pressure (p), and the equipment is characterized in that the equipment shell (10) is provided with at least two shell parts (16 and 18), the utility model relates to a device housing (10) comprising housing parts (16, 18) which are arranged one after the other when viewed along a longitudinal axis (20) of the device housing (10), the free cross-sections of the housing parts (16, 18) adjacent to one another differ, and wherein the transition of one housing part to the next adjacent housing part is implemented in the form of a step (22).

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of equipment, in particular for the equipment for carrying out volume compensation in fluid circuit, the equipment at least includes equipment shell and the compensation element that can be movably guided in the equipment shell, the compensation element can be supported on energy accumulator by fluid pressure loading. BACKGROUND

[0002] It is known from EP3191717B1 a device for pressure relief of hydraulic lines, in particular for pressure relief in connecting lines with coupling points between attachment devices with hydraulically actuatable actuators and working device rods supplying these attachment devices, which has a control block connected on the line to be relieved, which control block contains an unlockable non-return valve as pressure relief valve, which device has a pressure accumulator to accommodate the pressure relief volume when the non-return valve is unlocked and a handling element that can be moved manually for unlocking the non-return valve, which handling element is movably arranged on the device housing of the pressure accumulator, which pressure accumulator is designed as a spring accumulator, which spring accumulator has an accumulator piston that can be moved axially as compensation element, which accumulator piston is loaded on its side facing away from the fluid chamber by a pressure spring as accumulator and is penetrated by a coaxial handling rod, which handling rod extends with its inner end through a fluid inlet of the device housing to the closing body of the non-return valve. Furthermore, a handling knob for manually moving the handling rod is mounted on the outer end of the handling rod, which handling rod protrudes at the outer end of the device housing of the pressure accumulator. In the known solution, the device housing is composed of a pot-shaped, one-piece housing part, which has a hollow cylindrical outer shell and has an inner cross section, the diameter of which is constant.

[0003] The related spring accumulator provides a maintenance-free alternative to gas-filled pressure accumulators, since no refilling is required on the gas side. A further advantage is the temperature-independent characteristic curve, with which a wide temperature range can be covered without influencing the pressure-volume curve as in hydropneumatic accumulators. SUMMARY

[0004] Starting from this prior art, it is the task of the utility model to provide a device that further improves the known solution, in particular to improve the use possibilities of the known solution.

[0005] To this end, the utility model provides a kind of equipment for volume compensation, the equipment at least includes equipment shell and the compensation element movably guided in the equipment shell, the compensation element can be supported on energy accumulator by fluid pressure loading, the equipment shell has at least two shell parts, the shell part is successively arranged along the longitudinal axis of the equipment shell, the shell part adjacent to each other is different in its free cross section, and the transition of one shell part and next adjacent shell part is realized in the form of step, the equipment shell can be matched with the installation condition of site in a meaningful way in widened frame.By the matching of the shell part of the equipment shell mentioned, the equipment can be particularly placed in narrow installation space with structural space saving.Although cross section changes and different shell part designs accompanied thereby, rigid shell structure is realized in general, which also withstands high operating force without problem.

[0006] The equipment according to the utility model can preferably be used for volume compensation in a closed fluid circuit, so as to compensate the volume change with temperature thereby.The equipment can be used in both high pressure range and low pressure range.

[0007] The step mentioned is preferably composed of annular surface concentrically arranged with the longitudinal axis of the equipment shell, and the annular surface continuously establishes the transition between two adjacent shell parts.Here, the step is preferably composed of truncated cone, and the imaginary bottom surface of the truncated cone transitions into the shell part with larger free cross section, and the imaginary top surface of the truncated cone transitions into the adjacent shell part with smaller free cross section.Thereby, coordinated transition is realized between different shell parts of the equipment shell, so that possible stress peaks in this material area can be compensated without problem and load introduction via step is also distributed along the direction of two adjacent shell parts.

[0008] In a preferred embodiment of the equipment according to the utility model, it is provided that the shell parts adjacent to each other are respectively composed of hollow cylinder with circular cross section, and each hollow cylinder has cross section with diameter different from that of other cross section.

[0009] Here, it is preferably further provided that the shell part with relatively larger free cross section guides the compensation element, and the adjacent shell part with smaller cross section accommodates at least part of the energy accumulator.Thereby, hydraulic loading of the equipment can be realized via the outwardly open side in the equipment shell, without being damaged by energy accumulator installation into the equipment shell.

[0010] In a further preferred embodiment of the device according to the application it is provided that the energy accumulator consists of at least one, preferably two pressure springs, the spring wire of which extends in the spring chamber from the compensation element up to the closure in the device housing. Particularly in the case of the use of two helical pressure springs, a solution can be saved in terms of the constructional space length of the device housing with respect to a solution with only one spring and two springs of the same spring force.

[0011] Here, it is preferably provided that the outer spring wire surrounds the inner spring wire in a manner concentric to the longitudinal axis of the device housing and preferably has a greater spring stiffness than the inner spring wire. Here, it is preferably provided that at least a portion of the outer spring wire can be guided within a housing portion with a smaller free cross section and thereby supports outwardly against bending, which facilitates the overall guidance of the entire spring assembly in the device housing. The outer spring thereby additionally supports the inner spring.

[0012] For a particularly rigid configuration of the spring assembly it is provided that the coil pitch of the two pressure springs arranged concentric to one another differs from one another, the pressure springs being preferably configured cylindrically.

[0013] In a particularly preferred embodiment of the device according to the application it is provided that a guide is arranged within the device housing, which supports at least a portion of the pressure spring in the course of operation of the pressure spring in a manner projecting into the spring chamber. In the case of small pressures and relatively large volume movements, a correspondingly long spring is used, which in principle tends to bend. Due to the guide, which at least partially guides the inner spring wire, the associated bending is effectively counteracted.

[0014] Here, it is preferably provided that the guide consists of a tube, the interior of which is in media connection with the spring chamber, so that an obstruction in operation due to a possibly enclosed air volume is avoided. Particularly preferably, the tube consists of a telescopic tube, which can be reset from a retracted position achieved by means of a preferably piston-like configured compensation element into its pulled-out initial position by means of a reset device, in particular in the form of a magnet. Due to the telescopic guide it is possible to produce an effective support for the respective pressure spring on its respective inner side over a very wide movement path of the piston-like compensation element. Here, the piston-shaped compensation element can move the telescopic outer tube relative to the telescopic inner tube upon reaching a corresponding loading path within the device housing. Furthermore, the telescopic embodiment described makes it possible to stabilize the energy accumulator characteristic curve and to cause a reduction in the tipping tendency for the piston-shaped compensation element, which would otherwise normally be caused by the bending of the elongate spring. However, the device solution according to the application effectively eliminates the risk of tube bending.

[0015] In another preferred embodiment of the device according to this utility model, the tube body, in particular in the form of a telescopic tube, is inserted into a pressure compensation element on the side of a cap-like closure, the pressure compensation element passing through the cap-like closure. The device housing, together with its various housing parts, extends into the bottom of the housing at one of its free ends, the bottom of the housing forming the closure of the device housing. A pressure compensation element is inserted into the relevant cap-like closure, allowing ambient air to flow into or out of the interior of the device housing via the pressure compensation element, depending on the direction of movement of the compensation element. Due to the pressure compensation element, the enclosed air cannot be compressed inside the device housing (i.e., the spring chamber), enabling unobstructed operation of the device at all times. Thus, a breathing system, particularly in the form of a spring accumulator, is achieved.

[0016] Preferably, the hollow cylindrical shell portions interconnected via the stepped portions have the same wall thickness. Here, it is particularly preferred that the device shell and its shell portions be constructed as a single piece and preferably obtained in a single process step by means of cold extrusion. In this regard, the individual cylindrical outer shell surfaces of the shell portions interconnected via the stepped portions are preferably constructed together with the cap-like closure to form an integral cold-flow extruded part. Attached Figure Description

[0017] The device according to the present invention will now be explained in detail with reference to embodiments shown in the accompanying drawings. Here, the drawings are in principle and not to scale:

[0018] Figure 1 , Figure 2 Two different embodiments of the device according to the present invention are shown in a simplified longitudinal sectional view and in the initial state. Detailed Implementation

[0019] exist Figure 1 The device shown has a housing 10, which has a compensating element 12 that can be guided longitudinally therein, the compensating element being able to move along the direction of Figure 1 The line of sight is loaded by fluid pressure p on the left and supported on accumulator 14 on the right.

[0020] The device housing 10 has two housing portions 16 and 18, which are arranged sequentially when viewed along the longitudinal axis 20 of the device housing 10. The adjacent housing portions 16 and 18 differ in their free cross-sections, wherein the transition between one housing portion 16 and the immediately following, adjacent housing portion 18 is in the form of a stepped portion 22.

[0021] The step 22 is formed by an annular face 24 which is arranged concentrically to the longitudinal axis 20 of the device housing 10 and which establishes a transition between two adjacent housing portions 16, 18. The step 22 is formed in particular by a truncated cone, the imaginary, dashed circular base face 26 of which transitions into the housing portion 16 having the larger free cross section. The imaginary, also dashed top face 28 of the truncated cone transitions into the adjacent housing portion 18 having the comparatively smaller free cross section. The top face 28 also has a circular cross section like the base face 26.

[0022] The housing portions 16, 18 which are adjacent to one another, respectively, are formed by hollow cylinders having circular cross sections, wherein each hollow cylinder has a cross section whose diameter differs from the diameter of the other cross section. As is also derived from Figure 1 the larger free cross section guides the compensation element 12, and, conversely, the adjacent housing portion 18 which adjoins via the step 22 and which has the smaller cross section compared thereto accommodates at least a portion of the energy store 14.

[0023] The compensation element 12 is formed by a cylindrical hollow piston which has usual guide and sealing means on the outer peripheral side, insofar as in Figure 1 for the sake of simplicity only the associated annular groove 30 is shown. Via the associated, not shown guide and sealing means, the piston-like compensation element 12 slides with its outer periphery along the cylindrical inner peripheral face of the first housing portion 16. Insofar as the step 22 which tapers conically in the direction of the free end of the device housing 10 which is opposite the compensation element 12 is configured with a possible stop for the compensation element 12. Furthermore, the compensation element 12 is located in its initial position which is not actuated according to the illustration and insofar as on its side which faces the fluid pressure p supports on its piston top 32 along the outer periphery a circlip 34 which is accommodated in an associated inner peripheral groove 36 of the first housing portion 16 transversely to the orientation of the longitudinal axis 20. Figure 1

[0024] The energy store 14 mentioned is formed by two pressure springs 38, 40, the spring wire of which extends in a spring chamber 42 from the compensation element 12 up to a cover-like closure 44 in the device housing 10. The outer spring wire of the second pressure spring 40 surrounds the inner spring wire of the first pressure spring 38 in a manner which is arranged concentrically to the longitudinal axis 20, and the second pressure spring 40 has preferably a greater spring stiffness than the first pressure spring 38 which has its inner spring wire. The coil pitch of the two pressure springs 38, 40 which are arranged concentrically to one another differs from one another and is in particular along the direction of the longitudinal axis 20 increasing from the compensation element 12 to the closure 44. Figure 1 ​viewed in the direction of view, the coil pitch of the first pressure spring 38 is oriented to the right and the coil pitch of the second pressure spring 40 is oriented to the left. Furthermore, the pressure springs 38, 40 which are configured as helical pressure springs are substantially cylindrically configured. The two pressure springs 38, 40 support with their free end portions on the inside of the piston head 32 on the one hand and on the inside of the cover-like closure 44 on the other hand.

[0025] As further derived from the Figure 1 concentrically within the device housing 10 is provided a guide 46 which supports at least a portion of the pressure springs, in particular the inner pressure spring 38, in its operation in such a way that it projects into the spring chamber 42. In this regard, the guide 46 at least partially guides the inner spring wire of the pressure spring 38. The guide 46 is configured by a tube body, the interior 48 of which is in a media connection with the spring chamber 42. To this end, the tube body has individual openings 50 in the tube wall which extend in three groups diametrically around the longitudinal axis 20. Depending on the size of the respective passage 50, these can also be configured in the form of holes and together support the intended damping.

[0026] In the embodiment according to Figure 1 the tube body is configured by a telescopic tube 52 which has a telescopic outer tube 54 and a telescopic inner tube 56. The telescopic inner tube 56 is fixed stationary on the cover-like closure 44 on one of its free end regions, while the telescopic outer tube 54 is guided longitudinally movably along the outer circumference of the telescopic inner tube 56. In this regard, the two tubes 54, 56 are irrevocably in mutual engagement via a correspondingly configured stop 58. Furthermore, in the connection region 44 and on the telescopic inner tube 56 a sealing ring 60 is provided which seals the spring chamber 42 and the interior 48 of the telescopic tube 52 from the surroundings. The telescopic outer tube 54 has on its free end side facing away from the closure 44 a ring magnet 62 as part of a reset device 64. The other part of the relevant reset device 64 is a cylindrical steel body 66 which is preferably a one-piece component part of the piston head 32 of the compensation element 12. The ring magnet 62 releases a central opening 68 via which the interior 48 of the telescopic tube 52 is in media exchange with the spring chamber 42. Instead of the steel body 66, a similar body can also be manufactured in aluminum or in a plastic structure which then has on its end side a corresponding magnet piece or steel piece, for example in the form of a sheet.

[0027] If the fluid pressure p exerts a force on the outer piston face of the compensation element 12 which is greater than the spring force of the two pressure springs 38, 40, then the compensation element 12 is moved in the direction of the arrow Figure 1The spring force is thereby increased by the compression of the two pressure springs 38, 40. At the maximum fluid pressure p, the free end side of the steel body 66 comes into abutment with the free end side of the telescopic outer tube 54 and correspondingly entrains the telescopic outer tube to the right. Here, the telescopic outer tube 54 slides onto the telescopic inner tube 56 until the maximum possible stop position, in which the telescopic outer tube 54 comes into abutment with the cover-like closure 44.

[0028] However, as a rule the spring reaction force is already sufficient at an earlier point in time to effectively counteract the fluid pressure p, so that the telescopic outer tube 54 does not necessarily reach its stop position and / or the compensation element 12 comes into abutment with the step 22. If the fluid pressure p falls again completely, the two pressure springs 38, 40 relax and the piston-like compensation element 12 reaches its left-hand stop position again, in which the clamping ring 34 is fixedly arranged in the first housing part 16. Depending on the force balance between the fluid pressure p and the spring pressure, intermediate positions of the compensation element 12 are possible. During the reset movement, at least the steel body 66 entrains the ring magnet 62 in such a way that the telescopic tube 52 can again occupy its initial position with its two tubes 54, 56 in the Figure 1 position shown in the figure. For the associated reset movement, it is not absolutely necessary that the steel body 66 comes into abutment with the ring magnet 62; rather, the magnetic force must be just sufficient to perform the associated reset movement, at least to overcome the frictional force of the outer tube 54 on the outer circumference of the inner tube 56.

[0029] As is also derived from the Figure 1 diameter-reduced second housing part 18, the inner circumference provides support for the outward bending of the outer pressure spring 40, so that in this respect an outward bending in this region is not possible. Furthermore, an inward bending of the first pressure spring 38 is not possible, since the spring wire of the inner pressure spring 38 can support itself in its movement position on the outer circumference of the telescopic outer tube 54. Further support of the two pressure springs 38, 40 is derived from their concentric arrangement, in which the spring wire portions of the two pressure springs 38, 40 come into abutment with one another under load, if necessary.

[0030] Furthermore, the device also has a pressure compensation element 70 which passes through the cover-like closure 44 and opens on one side into the ambient environment and on the other side into the interior 48 of the stationary expansion sleeve 52. Since the pressure compensation element 70 implements a breathing system, in particular in the form of a spring accumulator, and depending on the direction of movement of the compensation element 12, ambient air can be introduced or removed into the interior of the device housing 10 in this way. Preferably, the pressure compensation element 70 has a not shown membrane in order to prevent the introduction of contaminants, such as water or dirt. Thereby, an exchange between ambient air and the interior of the device housing 10, in particular in the form of the spring chamber 42, takes place without compression of the air enclosed there, so that the variable pressure setting essentially depends on the prevailing fluid pressure p and the spring tension of the two pressure springs 38, 40. It goes without saying that the device solution according to the application is also sufficient with only one pressure spring, if appropriate, when the spring is designed correspondingly rigid.

[0031] The housing parts 16, 18 which are connected to one another via the step 22 have the same thin wall thickness, so that the device housing 10 is configured in one piece with its housing parts 16, 18 and is preferably obtained by means of a cold extrusion method. Depending on the extrusion method used, the respective wall thickness can also be implemented thicker or differently. The thin-walled design is preferred only for reasons of weight. In this regard, the device housing 10 can consist of a suitable steel material or preferably of aluminum with its bottom closure 44. Since the compensation element 12 is fixed outwardly via the circlip 34, the cover on the oil side of the device housing 10 can be omitted. If the proposed spring accumulator, whose device housing 10 guides air and in particular serves for volume compensation in a closed circuit at low pressure, is made of plastic, a plurality of parts, in particular in the form of the guide 46, can be made of plastic.

[0032] Furthermore, on the bottom side of the device housing 10, an outer thread 72 is mounted on the outer circumference adjacent to the circlip 34, so that the device can be screwed as a whole into a not shown housing block in a cartridge-like manner, which has at least one fluid guide which guides the fluid pressure p. The relevant fluid pressure p is usually generated via a fluid of a fluid circuit, for example in the form of a hydraulic medium. Overall, the device solution according to the application is implemented for a continuous radial spring guide of the respective pressure spring 38, 40. The construction of the device housing 10 as a cold flow extrusion allows a reliable reception of the occurring actuating forces in operation, which are determined by the fluid pressure p and the spring force of the respective pressure spring 38, 40. In the region of the outer thread 72, a further sealing ring 74 is provided, which performs a reliable sealing between the interior of the block and the ambient environment in the state in which the device housing 10 is screwed into the block or the like. Figure 1 ​

[0033] The following description is based on Figure 2 Another embodiment, only in this Figure 2 According to Figure 1 The implementation method is explained within the scope of substantially different Figure 2 If based on Figure 2 The implementation method uses according to Figure 1 For individual structural components, the same as that used in... Figure 1 The same reference numerals are used in the accompanying drawings, and the embodiments involved therein also apply to those described below. Figure 2 The solution. Based on... Figure 2 In one embodiment, a guide portion 46 with a separate tube body is used instead of the telescopic tube 52, on the outside of which the spring wire of the internal pressure spring 38 can be supported. The relevant tubular guide portion 46 engages with the actuating member, for example, in the region of a cylindrical steel body 66, via another retainer 76 and is further open at its opposite free end, allowing the interior 48 of the guide portion 46 to enter the spring chamber 42. Furthermore, in a relevant embodiment, the pressure compensation element 70 extends into the inner side of the device housing 10, or the spring chamber 42. The hollow cylindrical guide portion 46 is carried synchronously from left to right by means of the compensation element 12 until the free end of the guide portion 46 abuts against a wall-like closure 44, which in this respect constitutes a stable stop. Here, along the direction of this stop, the inner periphery of the guide portion 46 surrounds a portion of the outer periphery of the pressure compensation element 70, which allows for improved guidance in the stop region. In order to... Figure 1 In one embodiment, unloading of the stepped portion 22 can be at least specified such that the telescopic portion encounters a stop before the piston-shaped closing portion 12 contacts the stepped portion 22. Thus, in both embodiments, unloading of the accumulator housing 10 during operation is achieved.

Claims

1. Device for volume compensation, comprising at least a device housing (10) and a compensation element (12) movably guided in the device housing, which compensation element can be supported by fluid pressure (p) on an accumulator (14), characterized in that The device housing (10) has at least two housing parts (16, 18) which are arranged one after the other along a longitudinal axis (20) of the device housing (10), the housing parts (16, 18) adjacent to one another differ in their free cross section, and the transition of one housing part into the next adjacent housing part is realized in the form of a step (22).

2. The device for volume compensation according to claim 1, characterized in that, The device is a device for volume compensation in a fluid circuit.

3. The apparatus for volume compensation of claim 1, wherein, The step (22) is formed by an annular face (24) which is arranged concentrically to the longitudinal axis (20) of the device housing (10) and which establishes the transition between two adjacent housing parts (16, 18) continuously.

4. The device for volume compensation according to any one of claims 1 to 3, characterized in that, The step (22) is formed by a truncated cone, the imaginary base face (26) of which transitions into the housing part with the larger free cross section, and the imaginary top face (28) of which transitions into the adjacent housing part with the smaller free cross section.

5. The device for volume compensation according to any one of claims 1 to 3, characterized in that, The housing parts (16, 18) adjacent to one another are formed by hollow cylinders with circular cross sections, and each hollow cylinder has a cross section with a diameter which differs from the diameter of the other cross section.

6. The device for volume compensation according to any one of claims 1 to 3, characterized in that, The housing part with the correspondingly larger free cross section guides the compensation element (12), and the adjacent housing part with the smaller cross section accommodates at least a portion of the energy store (14).

7. The device for volume compensation according to any of claims 1 to 3, characterized in that, The energy store (14) is formed by at least one pressure spring, the spring wire of which extends in a spring chamber (42) from the compensation element (12) to a closure (44) in the device housing (10).

8. The device for volume compensation according to claim 7, characterized in that, The energy store (14) is formed by two pressure springs (38, 40).

9. The device for volume compensation according to claim 8, characterized in that, The spring wire located on the outside surrounds the spring wire located on the inside in a concentric arrangement with respect to the longitudinal axis (20) of the device housing (10).

10. The apparatus for volume compensation of claim 8, wherein, The spring wire located on the outside surrounds the spring wire located on the inside in a concentric arrangement with respect to the longitudinal axis (20) of the device housing (10) and has a greater spring stiffness than the spring wire located on the inside.

11. The device for volume compensation according to any one of claims 8 to 10, characterized in that, The coil pitches of the two pressure springs (38, 40) arranged concentrically to one another differ from one another.

12. The device for volume compensation according to any one of claims 8 to 10, characterized in that, The two pressure springs (38, 40) are configured cylindrically.

13. The device for volume compensation according to any one of claims 8 to 10, characterized in that, A guide (46) is arranged within the device housing (10), which at least for a portion of the pressure spring provides support in the operation of the pressure spring in the manner of a protrusion into the spring chamber (42).

14. The apparatus for volume compensation according to claim 13, characterized in that, The guide (46) guides at least the spring wire located on the inside.

15. The apparatus for volume compensation of claim 13, wherein, The guide (46) is formed by a tube, the interior (48) of which is in media connection with the spring chamber (42).

16. The apparatus for volume compensation of claim 15, wherein, The tube is formed by a telescopic tube (52) which can be reset into its pulled-out initial position from a displaced-in position realized by means of the compensation element (12) by means of a reset device (64).

17. The apparatus for volume compensation of claim 16, wherein, The reset device (64) is in the form of a magnet (62).

18. The apparatus for volume compensation of claim 16, wherein, The compensation element (12) is configured in the manner of a piston.

19. The apparatus for volume compensation of claim 15, wherein, The tube body opens out into a pressure compensation element (70) on the side of the closure (44) of the cap-like configuration, which passes through the closure (44).

20. The device for volume compensation according to any one of claims 16 to 18, characterized in that, The telescopic tube (52) opens out into a pressure compensation element (70) on the side of the closure (44) of the cap-like configuration, which passes through the closure (44).

21. The apparatus for volume compensation of claim 19, wherein, Ambient air can flow into or out of the interior of the device housing (10) in the form of a breathing system by means of the pressure compensation element (70) depending on the direction of movement of the compensation element (12).

22. The apparatus for volume compensation of claim 21, wherein, The breathing system is in the form of a spring accumulator.

23. The device for volume compensation according to any of claims 1 to 3, characterized in that, The hollow-cylindrical housing parts (16, 18) connected to one another via the step (22) have the same wall thickness.

24. The device for volume compensation according to any of claims 1 to 3, characterized in that, The device housing (10) is configured in one piece with its housing parts (16, 18).

25. The device for volume compensation according to any of claims 1 to 3, characterized in that, The device housing (10) is configured in one piece with its housing parts (16, 18) and is obtained by means of a cold extrusion method.

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