Rock crusher and method for storing pressure energy

Abstract

A pressure accumulator, a hydraulic rock breaker and a method for storing pressure energy. The pressure accumulator comprises a housing and an elastic diaphragm arranged inside the housing. The elastic diaphragm divides the internal space of the housing into two independent pressure spaces. The gas space is pre-filled with pressurized gas. On the opposite side of the elastic diaphragm is a hydraulic space for receiving hydraulic fluid. The elastic diaphragm is a cap-shaped element, which comprises a side wall, a mounting flange at its open end and a closed end. The mounting flange of the elastic diaphragm is mounted between the housing and a flange element. The pressure accumulator has no screen. The flange element is provided with a seal for sealing the piston.

Description

Technical Field

[0001] The invention relates to a pressure accumulator which can be mounted to a hydraulic system of a rock breaker and is intended to store pressure energy when an impact piston of an impact device of the rock breaker moves in a return direction.

[0002] The invention also relates to a rock breaker provided with a pressure accumulator for storing pressure energy during operation of the machine and its reciprocating impact piston. Furthermore, the invention relates to a method for storing pressure energy. Background Art

[0003] A breaker is a rock breaker used to break boulders, stones and other rock materials. The breaker includes a percussion device for generating impact pulses to a breaking tool that can be connected to the breaker. The breaker is usually installed in an excavator instead of in a bucket as an auxiliary device, and the breaker is usually operated by the hydraulic device of the base machine. Hydraulic breakers and other rock breakers provided with percussion devices use different pressure accumulators, for example, to smooth the pressure changes caused by the operating cycle of their percussion devices. The pressure accumulator includes a space that is divided into a gas space containing a pre-filled gas and a hydraulic space capable of receiving a hydraulic fluid by a pressure-sealed diaphragm. When hydraulic fluid is supplied to the hydraulic space, the hydraulic fluid pushes the diaphragm towards the gas space, thereby compressing the pre-filled gas on the opposite side of the diaphragm. The structure then simultaneously stores energy that can be released in order to supply the pressure fluid back to the hydraulic circuit. In this way, a certain volume of pressurized fluid can be temporarily stored in the pressure accumulator. However, the known solutions have been shown to include some disadvantages. Summary of the invention

[0004] It is an object of the present invention to provide a novel and improved rock crusher.It is a further object to provide a novel and improved method of storing pressure energy in a rock crusher.

[0005] The idea of ​​the disclosed solution is that the pressure accumulator comprises a housing defining an internal space, inside which an elastic gas-tight diaphragm is arranged. The diaphragm divides the internal space into two independent pressure spaces. The gas space is pre-filled with pressurized gas, and the hydraulic space is intended for receiving a hydraulic fluid. The diaphragm has radial side walls, an edge at its open first axial end and a closed top end at its opposite second axial end. The edge of the diaphragm comprises a transverse mounting flange, whereby the diaphragm has a cap-like configuration. The edge of the diaphragm is mounted between the housing and the mounting flange and is squeezed in the axial direction of the accumulator by a flange element. In addition, the flange element comprises one or more pressure channels for feeding hydraulic fluid to the hydraulic space and for discharging hydraulic fluid. The pressure channel allows a flow of hydraulic fluid from a hydraulic operating system of a rock breaker to be supplied to the hydraulic space and a flow of hydraulic fluid from the hydraulic operating system of the rock breaker to flow out of the hydraulic space during operation of the machine. The inner surface of the support portion of the flange element is provided with a seal for sealing the end portion of the impact piston of the hydraulic rock breaker.

[0006] In other words, the disclosed accumulator has no screen supporting the diaphragm, but only the lowermost part of the diaphragm is supported by the supporting part of the flange element and the upper part of the diaphragm is without any mechanical support.

[0007] Furthermore, in the disclosed barrier-free or barrier-free construction, the diaphragm is arranged between the housing and the flange element, whereby the housing, the diaphragm and the flange element are arranged one after the other in the axial direction of the pressure accumulator.

[0008] An advantage of the disclosed solution is that the accumulator can have a compact construction due to the absence of a barrier inside the accumulator. In the disclosed barrier-free accumulator, the volume of the barrier can be used to store pressure fluid inside it, instead of having a dead barrier volume. Furthermore, when the barrier is omitted, the structure of the accumulator can be simple, light and cheap.

[0009] Since the diaphragm has a mounting flange, it is easy to handle and install. In addition, the fastening between the housing and the flange element is firm and reliable.

[0010] The diaphragm is made of an elastic material and is configured to expand radially and axially in the space between the inner surface of the housing and the outer surface of the flange element due to the relative pressure prevailing in the gas space and the hydraulic space. Due to the simultaneous expansion in the axial direction and the radial direction, the expansion of the diaphragm can be relatively small and the desired flow of hydraulic volume can still be received in the hydraulic space.

[0011] Since the pressure accumulator is located at the rear end portion of the rock breaker, i.e. at the opposite end with respect to the tool-side end of the machine, the accumulator is located away from the front end portion which may be exposed to harmful influences of external forces and dust during use of the machine. This is very important, especially when there is no protective housing around the impact device. Furthermore, the accumulator is easy to install and service when it is located at the extension of the machine. Since the accumulator is easily accessible, service measures can be carried out under job site conditions.

[0012] According to an embodiment, the accumulator is suitable for use in a breaker hammer and a rock drill, both of which include a hydraulically operable impact device provided with a reciprocating impact piston. The breaker hammer and the drill are intended for rock breaking. In other words, the term rock breaker includes hydraulic breaker hammers and hydraulic rock drills.

[0013] According to an embodiment, the flange element comprises an annular mounting portion transverse to the axial direction of the accumulator.The above-mentioned pressure channel for feeding and discharging hydraulic fluid is located at said mounting portion.

[0014] According to an embodiment, the flange element comprises a central sleeve-like support portion axially protruding inside the housing, whereby an outer surface of the support portion is configured to provide axial support for the diaphragm at least when the hydraulic rock breaker is not pressurized.The support portion has a truncated configuration.

[0015] According to an embodiment, the housing of the accumulator is provided with a feed port for feeding pre-fill gas into the gas space, whereas the hydraulic space is connectable to an operating hydraulic system of the hydraulic rock breaker.

[0016] According to an embodiment, the flange element of the accumulator is provided with hydraulic fluid conduits for feeding hydraulic fluid to and discharging hydraulic fluid from the hydraulic space, whereby the pressure of the hydraulic fluid inside the hydraulic space is configured to be regulated during operation of the accumulator.

[0017] According to an embodiment, the edge of the diaphragm is pressed between the housing and the flange element in the axial direction of the accumulator. The resulting axial force ensures pressure sealing and secure fastening of the diaphragm. In addition, due to the imposed axial mounting direction, the housing and the diaphragm are easy to install and remove.

[0018] According to an embodiment, the edge of the diaphragm comprises a transverse mounting flange, whereby the diaphragm has a cap-like configuration. The mounting flange of the diaphragm extends radially away from the side wall and has an annular shape. In other words, the cap-like diaphragm has a cup-shaped portion and a rim around its open end portion.

[0019] According to an embodiment, the mounting flange of the diaphragm is provided with at least one protrusion at least on one side of the flange, and the mounting flange serves as a sealing element. Furthermore, at least one of the axial mounting surfaces between the housing and the flange element is provided with a groove for receiving the at least one protrusion. An advantage is that no separate sealing element is required, since the integrally integrated sealing arrangement comprises compatible protrusions and grooves.

[0020] According to an embodiment, the axial length of the sleeve-shaped support portion of the flange element is at least 1 / 4 of the axial length of the accumulator.The support portion then provides suitable support for the diaphragm.

[0021] According to an embodiment, the outer side surface of the sleeve-shaped support portion of the flange element is inclined towards the distal end of the support portion, so that the support portion tapers towards the distal end. In other words, the shape of the support portion may correspond to the shape of a truncated cone. The inclined side surface then provides axial support for the diaphragm when the hydraulic system is not pressurized.

[0022] According to an embodiment, the outer side surface of the sleeve-like support portion of the flange element is curved at least at its distal end portion.The curved surface is gentle to the diaphragm.

[0023] According to an embodiment, at a distal portion of the sleeve-like support portion of the flange element is a central inwardly tapered portion extending a limited axial distance towards the mounting portion of the flange element, whereby an outermost portion of the inner surface widens towards the distal end of the support portion.

[0024] According to an embodiment, the diaphragm is configured to close the pressure channel at the end of the discharge phase of the hydraulic space, thereby being configured to act as a non-return valve for the pressure channel. In other words, when the hydraulic space is not pressurized, the diaphragm can prevent the hydraulic space from being completely emptied. The remaining hydraulic fluid remaining in the hydraulic space can support the diaphragm and thus can prevent the diaphragm from being stretched and worn. Another advantage is that when the diaphragm is provided with a non-return valve feature, no other valve device is required.

[0025] According to an embodiment, the pressure channel of the flange element is located at the joint portion or root of the flange element, ie at the section where the annular mounting portion of the flange element becomes the supporting portion.

[0026] According to an embodiment, the pressure channel is axially directed.Then, the channel is easy and cheap to manufacture.

[0027] According to an embodiment, the number of pressure channels is at least 12, but may be up to 24.

[0028] According to an embodiment, all pressure channels are located on the same imaginary perimeter on the mounting portion of the flange element.

[0029] According to an embodiment, the closed end of the diaphragm comprises a top surface portion facing the gas space. The top surface comprises an annular edge portion, a center portion and an annular recessed portion therebetween. Furthermore, according to an embodiment, all of the mentioned portions (i.e. the edge portion, the center portion and the recessed portion) have a curved cross section.

[0030] According to an embodiment, the diaphragm is provided with a curved connecting portion having an increased material thickness between the lateral mounting flange and the side surface.Thereby, the durability of the diaphragm may be increased.

[0031] According to an embodiment, the sidewalls of the diaphragm are angled relative to the axial centerline of the accumulator. Thus, the sidewalls are open towards the open end of the diaphragm. The angled sidewalls may have a positive effect on the controlled expansion movement of the diaphragm. They may also be advantageous for the durability of the diaphragm.

[0032] According to an embodiment, the diaphragm is made of an elastic polyurethane (PU) material. Polyurethane has excellent mechanical properties and durability. In addition, polyurethane has good fatigue resistance, and polyurethane exhibits large and reversible ductility.

[0033] According to an embodiment, the membrane is made of another polymer or plastic material than polyurethane.

[0034] According to an embodiment, the diaphragm is made of a rubber material (e.g., nitrile rubber). The advantage of rubber is that rubber provides good sealing properties because rubber is relatively soft. In addition, nitrile rubber is cheap and has good resistance to hydraulic oil.

[0035] According to an embodiment, the inner surface of the side wall of the diaphragm is provided with a number of ribs which protrude inwardly towards the outer surface of the support portion of the flange element. The ribs keep the inner surface of the diaphragm at a short distance from the outer surface of the flange element, whereby hydraulic fluid can flow between the support portion of the flange element and the diaphragm. The ribs may contribute to a controlled operation of the diaphragm. The direction of the ribs may be substantially in the axial direction of the accumulator.

[0036] According to an embodiment, the solution relates to a hydraulic rock breaker, which can be a hydraulic breaker hammer or a rock drill. The machine is provided with a percussion device or impact device, which comprises a frame and a piston arranged in the frame. The piston is constructed to perform a reciprocating longitudinal movement due to the pressure of a hydraulic fluid fed to the percussion device. A crushing tool or a drilling tool can be connected to the percussion device and can receive an impact pulse from the percussion device. The percussion device has a hydraulic system, which comprises a feed port for feeding hydraulic fluid into the percussion device and a discharge port for discharging the pressure fluid out of the percussion device. A pressure conduit is also required to guide the pressure fluid into and out of the working pressure space of the piston so that the piston can move in the impact direction and the return direction. A pressure accumulator is connected to the hydraulic system to store hydraulic pressure energy. The pressure accumulator is located at the extension of the piston so that during the operation of the percussion device, the upper end of the piston moves inside the hydraulic space of the accumulator. The pressure accumulator comprises a housing, a diaphragm and a flange element, which are arranged one after another in the axial direction of the percussion device. The top end portion of the piston is sealed to the flange element of the accumulator. Thus, there is a dynamic seal between the flange element and the piston. Furthermore, the flange element is also provided with a pressure fluid conduit for feeding hydraulic fluid to the hydraulic space and for discharging hydraulic fluid from the hydraulic space. Thus, the flange element can form the top end of the impact device. Furthermore, the pressure accumulator has no barrier and no mechanical fixing structure between the piston and the diaphragm in the axial direction of the accumulator. Thus, the top end of the piston directly faces the inner surface of the diaphragm. The accumulator may also include the above-mentioned more detailed features disclosed in this document.

[0037] According to an embodiment, the diaphragm may contact the top end of the impact piston when the impact device is not pressurized.

[0038] According to an embodiment, the top end of the impact piston comprises a rounded edge. Thus, the piston is gentle to the diaphragm if or when the piston and the diaphragm come into contact with each other.

[0039] According to an embodiment, a hydraulic rock breaker (e.g., a hydraulic breaker hammer) comprises a high-pressure circuit, a low-pressure circuit, and a tank pressure circuit. The disclosed accumulator is connected to the low-pressure circuit. The low-pressure circuit is continuously connected to the hydraulic space of the accumulator, and the top of the impact piston is continuously affected by the low pressure of the low-pressure circuit. The pressure of the low-pressure circuit can be adjusted by a valve. The low-pressure circuit is also called a medium-pressure circuit because its pressure is between the high-pressure circuit and the tank pressure circuit or the discharge pressure circuit. For example, the average operating pressure in the low-pressure circuit can be 40 bar.

[0040] According to an embodiment, the pre-fill pressure inside the gas space is 15-20 bar.During operation, the diaphragm compresses the pre-fill gas and causes the pressure in the gas space to increase.

[0041] According to an embodiment, the working cycle of the percussion device is controlled by a pressure-controlled sleeve-like control valve arranged around the piston. The top part of the control valve extends inside the flange element of the accumulator. The flange element can then be provided with a control pressure channel.

[0042] According to an embodiment, the flange element may include a sleeve-like protrusion extending from the rear end of the impact device toward the front end of the impact device. Then, the sleeve-like protrusion and the base of the impact device may have an overlapping connection. The protrusion may provide a support surface for the control valve of the impact device.

[0043] According to an embodiment, the pressure accumulator is only partially positioned around the impact piston along its axial length.The top portion of the piston can move inside the hydraulic space of the accumulator, but not through the accumulator as it would in a sleeve-like accumulator.

[0044] According to an embodiment, the hydraulic space of the accumulator is connected to the hydraulic system of the striking device, and the pressure fluid is configured to flow to and from the hydraulic space during operation of the striking device. Therefore, the hydraulic space of the accumulator is affected by the hydraulic fluid flow of the striking device. In other words, the hydraulic space is not a closed pressure space provided with a pre-filled amount of hydraulic fluid, but the hydraulic fluid circulates in the hydraulic space.

[0045] According to an embodiment, the crusher further comprises at least one valve for regulating the pressure of the hydraulic fluid prevailing in the hydraulic system connected to the pressure accumulator. The valve may be configured to automatically regulate the pressure of the hydraulic space of the accumulator. The valve may be integrated as part of the machine or, alternatively, the valve may be a separate component external to the body of the machine.

[0046] According to an embodiment, the pressure in the hydraulic space of the accumulator is 30-45 bar, with a typical average being 40 bar. The accumulator is therefore connected to a low-pressure or medium-pressure circuit.

[0047] According to an embodiment, the top end of the impact piston facing the hydraulic space of the accumulator is rounded. In other words, the top of the piston is shaped so that it has a curved surface facing the inner surface of the diaphragm, whereby the piston is gentle to the diaphragm in case of contact between the piston and the diaphragm when the machine is not hydraulically pressurized. Therefore, the piston will not damage the diaphragm in any case.

[0048] According to an embodiment, the piston is provided with a central protrusion for supporting the diaphragm against tensile deformation when the machine is not pressurized and the diaphragm is subjected to the force of the pre-fill gas pressure. The top of the protrusion may be curved or rounded so that it does not damage the diaphragm.

[0049] According to an embodiment, the method comprises controlling the flow of hydraulic fluid from the hydraulic space by means of a diaphragm. The diaphragm then acts as a check valve and the diaphragm prevents the hydraulic fluid space from being completely emptied. Due to the check valve feature, harmful stretching of the diaphragm can be prevented when the hydraulic system is not pressurized.

[0050] According to an embodiment, the solution relates to a method for storing hydraulic energy in a hydraulic breaker or in a hydraulic rock drilling machine. The method comprises providing a percussion device of a hydraulic machine having at least one pressure accumulator, the at least one pressure accumulator comprising a gas space and a hydraulic space separated by a diaphragm. The method further comprises pre-filling the gas space with pressurized gas and receiving the top end portion of a reciprocating piston of the percussion device of the breaker inside the hydraulic space during operation of the percussion device. The hydraulic volume inside the hydraulic space then changes due to the protruding top end portion of the piston. The accumulator compensates for the volume change of the hydraulic space by allowing the diaphragm to expand towards the gas space. The diaphragm has a cap-like configuration and the diaphragm may have the detailed features disclosed in the present document. Furthermore, the diaphragm is axially mounted between two axial mounting surfaces by squeezing a mounting flange located at the open end of the diaphragm. Another concept is to leave the diaphragm without any support constituted by a barrier element.

[0051] According to an embodiment, the method comprises receiving hydraulic fluid from a hydraulic circuit of the rock breaker into a hydraulic space during operation of the rock breaker, and correspondingly discharging hydraulic fluid from the hydraulic space to the hydraulic circuit. In other words, the hydraulic fluid circulates inside the hydraulic space, whereby the hydraulic space is not a closed pressure space.

[0052] According to an embodiment, the method comprises: when the impact device of the rock breaker is in operation and the hydraulic space is not pressurized, under the influence of the pre-filling gas pressure, pressing the inner surface of the radial side wall of the cap-shaped diaphragm against the outer surface of the support portion of the flange element. For the same reason, the diaphragm can also be pressed against the top surface of the piston.

[0053] According to an embodiment, the method comprises: regulating the hydraulic pressure prevailing inside the hydraulic space by means of a valve. The valve can set a pressure that constantly prevails in the low-pressure system of the percussion device.

[0054] According to an embodiment, the method comprises using a diaphragm having a cap-like configuration. The mounting of the diaphragm comprises axially pressing a mounting flange located at the open end of the diaphragm between two axial mounting surfaces. In other words, the diaphragm has an axial mounting system. The mounting surfaces are formed to the flange element and the housing. There is free space on the rear end side of the impact device, whereby handling of the components at the rear end side is easy.

[0055] It is worth mentioning that the disclosed pressure accumulator and pressure storage principle are also suitable for use in other types of percussion devices than those disclosed in this document.

[0056] The above disclosed embodiments can be combined to form a desired solution having the disclosed necessary features. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Some embodiments are described in more detail in the accompanying drawings, in which:

[0058] Figure 1 is a schematic side view of an excavator provided with a hydraulic breaker,

[0059] Figures 2 to 4 is a schematic cross-sectional side view of the impact device and its accumulator,

[0060] Figures 5 to 7 is a schematic diagram of the cap-shaped diaphragm of the accumulator,

[0061] Figure 8 and Fig. 9 is a schematic diagram of a flange element provided with a truncated support portion and a sleeve element,

[0062] Fig.10 is a schematic diagram illustrating some of the problems associated with hydraulic rock breakers, and

[0063] Fig.11 is a schematic diagram of a rock drilling unit.

[0064] For the sake of clarity, the drawings show some embodiments of the disclosed solution in a simplified manner. In the drawings, the same reference numerals represent the same elements. DETAILED DESCRIPTION

[0065] Figure 1 A breaker hammer 1 is shown which is arranged on the free end of a boom 2 of a working machine 3, such as an excavator. Alternatively, the boom 2 can be arranged on any movable carrier or on a fixed platform of a crushing device. The breaker hammer 1 comprises an impact device 4 for generating impact pulses. The breaker hammer 1 can be pressed against the material 5 to be crushed by the boom 2 and a tool 6 connected to the breaker hammer 1 can be impacted simultaneously with the impact device 4. The tool 6 transmits the impact pulse to the material 5 to be crushed. The impact device 4 is hydraulically operable, whereby the impact device 4 can be connected to the hydraulic system of the working machine 2. The impact pulse can be generated in the impact device 4 by an impact piston which moves back and forth in an impact direction and a return direction under the influence of a hydraulic fluid. A hydraulic pressure accumulator is located at the rear end 7 of the breaker hammer, which is located at the rear end 7 of the breaker hammer. Figures 2 to 4 Shown in.

[0066] Figure 2 The rear end 7 or upper end portion of the breaker 1 is disclosed. A hydraulic accumulator 8 is located in the extension of the percussion device 4, which comprises a piston 9 that can move in an impact direction A and a return direction B. Figure 2 In the embodiment of the present invention, the piston 9 has performed its striking movement and is located in its lowest position. The accumulator 8 comprises a housing 10, which is mounted against an axial mounting surface 11 of a body 12. The accumulator 8 also comprises a flange element 13, which can be pressed against the mounting surface 11 by means of a fastening screw of the housing 10. An elastic diaphragm 16 is located inside the accumulator 8, and the edge of the elastic diaphragm 16 is mounted between the housing 10 and the flange element 13. The diaphragm 16 divides the internal space of the housing 10 into a gas space 17 and a hydraulic space 18. The hydraulic space 18 is located in the interior of the accumulator 8. Figure 4 1 is best shown in FIG. 1 . As can be seen, the flange element 13 provides support for the diaphragm 16. Pressurized gas is located inside the gas space 17. The housing 10 is provided with a feed port 19 for feeding pre-filled gas into the gas space 17. The hydraulic space 18 is connected to the operating hydraulic system of the impact device 4 via a pressure channel 20. The top end 22 of the piston 9 moves inside the flange element 13 and causes a volume change of the hydraulic fluid inside the hydraulic space 18. The top end portion of the piston 9 is sealed to the flange element 13 by a seal 23. The reciprocating movement of the piston 9 is controlled by a sleeve-like control valve 24, which is arranged around the piston 9 and is provided with control surfaces for controlling the hydraulic pressure acting on the working pressure surfaces of the piston 9. The first working pressure surface (not shown) is continuously pressurized and moves the piston 9 towards the return direction B. The hydraulic pressure acting on the second working pressure surface and the third working pressure surface is controlled by the control valve 24. The working pressure surfaces selectively receive the hydraulic fluid flow of the high pressure circuit and the tank pressure circuit. Since the accumulator 8 is connected to the low-pressure circuit, the top end 22 of the piston 9 is constantly subjected to low pressure. When the control valve 24 connects the working pressure surface to the high-pressure circuit, the piston 9 moves toward the impact direction A because the surface area of ​​the working pressure surface is greater than the surface area of ​​the first working pressure surface. Likewise, the low pressure prevailing in the accumulator 8 and acting on the top surface 22 generates a force for moving the piston 9 in the impact direction A.

[0067] Figure 2 It is also disclosed that the flange element 13 may include a sleeve-like portion 28, which protrudes toward the front end and surrounds the control valve 24. Thus, the flange element 13 can provide support for the control valve 24 and also be provided with a pressure channel. Due to the sleeve-like portion 28 of the flange element 13, the structure of the base body 12 can be simple. Different collars, fittings and pressure channels are easier to form in a separate component 13 than in a large-sized main body 12.

[0068] Figure 2It is also disclosed that both the inner surface of the housing 10 and the diaphragm 16 have a shape that substantially corresponds to the shape of a hat. The housing 10 may include a protective sleeve 32 surrounding the accumulator 8 .

[0069] exist Figure 2 In FIG. 1 , the gas space 17 is pre-filled with pressurized gas and the hydraulic space 18 is unpressurized because the impact device is not active. Therefore, the gas pressure presses the diaphragm 16 against the outer surface of the protruding support portion 14 of the flange element 13. As can be noted, the central part of the diaphragm 13 can then contact the top surface 22 of the piston 9 and also the inclined surface of the recess 53 at the top of the support portion. Figure 3 In the embodiment of the present invention, the hydraulic space 18 is still unpressurized, but the piston 9 has moved in the return direction B because the tools of the crusher 1 are pressed against the material to be crushed.

[0070] exist Figure 4 In the embodiment of the present invention, the impact device 4 is pressurized and the piston 9 moves to its rearmost position in the return direction B. The hydraulic fluid is then pushed by the piston 9 and the diaphragm 16 is pushed towards the inner surface of the housing 10. The volume of the gas space 17 decreases. The small arrows indicate that during the return movement of the piston 9, the diaphragm 16 expands axially and laterally.

[0071] Figures 2 to 4 It is also shown that the edge 33 of the diaphragm 16 comprises an annular mounting flange 21, which is provided with a protrusion 34 facing the top surface of the annular mounting portion 15 of the flange element 13. The mounting portion of the flange element 13 is provided with a groove 35 or other form of surface that can receive the protrusion 34, whereby they can together form a sealing element. Alternatively or additionally, the protrusion 34 can be formed on the top side of the mounting flange 21, and the housing 10 can be provided with said groove 35. The accumulator 8 and all its components are mounted and disassembled in the axial direction. The housing 10 is fastened to the rear mounting surface 11 of the body 12 by means of fastening screws. As a result, the mounting flange 21 of the diaphragm 16 is tightly pressed between the axial mating surfaces of the housing 10 and the flange element 13 by the axial force F.

[0072] Figure 4 It is also disclosed that the top end 22 of the piston 9 may include a rounded outer edge 50. Alternatively, the entire top end may have a curved configuration 51.

[0073] Figures 2 to 4 It is also disclosed that the pressure channels 20 are located at the root of the flange element 13 and that the diaphragm 16 is arranged to close these pressure channels 20 when the pre-filling gas pressure of the gas space 17 pushes the diaphragm 16 towards the flange element 13 and the hydraulic space 18 is not pressurized. The diaphragm then closes the pressure channels, as Figure 2 and Figure 3As shown. Figure 4 In this embodiment, the diaphragm 16 is in its expanded state and the pressure channel 20 is of course open.

[0074] Figures 5 to 7 A diaphragm 16 having a hat-like shape is disclosed, which has a closed end 53 and an annular mounting flange 21 at an open end 54. Then, the edge 33 of the diaphragm 16 is provided with an annular transverse portion. The mounting flange 21 may include a protrusion 34, which may be a sealing protrusion. There may or may not be several ribs 55 inside the diaphragm 16. The closed end 53 of the diaphragm 16 may include a curved central portion 39. An angled side wall 40 is between the top surface and the mounting flange 21, and there is a curved middle portion 41 or recess between the side wall and the top surface. The annular edge 56 may also be curved. In addition, there may be a curved section 57 with increased material thickness at the root. As disclosed above in this document, this portion of the diaphragm 16 can be used as a valve portion. The shape of the diaphragm 16 can resemble a cowboy hat.

[0075] Figure 8 and Fig. 9 A flange element 13 is disclosed which is provided with an integral support portion 14 and a sleeve-like portion 28. The disclosed flange element 13 is a multi-purpose component which serves to axially support the diaphragm, as a mounting support for the diaphragm, and also provides the required control pressure passage and support for the control valve and operating system.

[0076] The top of the support portion 14 is open so that the piston can pass through it. The side surface 58 of the support portion 14 is inclined so that the support portion tapers towards its distal end. The outermost edge 59 is rounded. All other features have been disclosed above in this document.

[0077] Fig.10 4 is a schematic diagram showing that the hydraulic rock breaker 43 can be a hydraulic breaker 1 or a rock drill 44. The common feature of these machines is at least the fact that they all include a hydraulic percussion device 4 and a hydraulic accumulator 8. In addition, they are used to break rocks or rock materials. The structure of the percussion device 8 and its detailed operating principle can be different from those already described. Figures 2 to 4 Therefore, the disclosed accumulator 8 can be applied in a universal manner with different configurations.

[0078] Fig.11A rock drilling unit 45 is disclosed, which comprises a rock drill 44 supported in a movably manner on a feed beam 46. The rock drill 44 comprises a percussion device provided with a reciprocating piston 9, which is arranged to strike an impact surface of a shank 47. A drilling tool 48 is connected to the shank 47, and the shank 47 can be rotated by a rotating device 49. When a drill bit 60 is pushed and, at the same time, an impact pulse is directed toward the drilling tool 48, the drill bit crushes the rock material and forms a borehole 61. In order to compensate for the pressure fluctuations caused by the reciprocating movement of the piston 9, there is a hydraulic accumulator 8 in the axial extension of the percussion device 4. The accumulator 4 comprises a housing, a flange element and an elastic diaphragm between the housing and the flange element. The basic structure of the accumulator 4 is consistent with the features and problems disclosed in this document.

[0079] The drawings and the related description are intended only to illustrate the idea of ​​the invention. The invention may vary in its details within the scope of the claims.

Claims

1. A hydraulic rock breaker (43), comprising: a percussion device (4) comprising a frame and a piston (9) arranged inside the frame and configured to perform a reciprocating longitudinal movement due to the pressure of a hydraulic fluid fed to the percussion device (4); a tool (6, 48) connectable to the impact device (4) and configured to receive an impact pulse from the impact device (4); A hydraulic system of the impact device (4), the hydraulic system comprising a feed port, a discharge port and a pressure conduit, wherein the feed port is used to feed hydraulic pressure fluid into the impact device (4), the discharge port is used to discharge the pressure fluid from the impact device (4), and the pressure conduit is used to guide the pressure fluid to the working pressure space of the piston (9) and guide the pressure fluid out of the working pressure space of the piston (9); as well as a pressure accumulator (8) for storing hydraulic pressure energy and connected to the hydraulic system; wherein the pressure accumulator (8) is located in extension of the piston (9) so that during operation of the impact device (4), the upper end of the piston (9) moves inside the hydraulic space (18) of the pressure accumulator (8), and wherein the pressure accumulator (8) comprises: A housing (10), wherein the housing (10) defines an internal space; an elastic diaphragm (16) arranged inside the interior space and configured to divide the interior space into two independent pressure spaces, wherein a gas space (17) is pre-filled with pressurized gas and on the opposite side of the elastic diaphragm (16) is a hydraulic space (18) for receiving a hydraulic fluid; Flange element (13); and wherein the elastic diaphragm (16) has a radial sidewall (40), an edge (33) and a closed end (53), wherein the edge (33) is at an open first axial end of the elastic diaphragm (16), and the closed end (53) is at an opposite second axial end of the elastic diaphragm (16); and the edge (33) of the elastic diaphragm (16) is mounted between the housing (10) and the flange element (13); It is characterized in that The edge (33) of the elastic diaphragm (16) comprises a transverse mounting flange (21), whereby the elastic diaphragm (16) has a cap-like configuration; The mounting flange (21) of the elastic diaphragm (16) is pressed between the housing (10) and the flange element (13) in the axial direction of the pressure accumulator (8); the flange element (13) comprising at least one pressure channel (20) for feeding hydraulic fluid into the hydraulic space (18) and for discharging hydraulic fluid, whereby the pressure channel (20) allows a flow of hydraulic fluid from a hydraulic operating system of the hydraulic rock breaker to be supplied to the hydraulic space (18) and a flow of hydraulic fluid from a hydraulic operating system of the hydraulic rock breaker to flow out of the hydraulic space (18) during operation of the hydraulic rock breaker; The flange element (13) comprises a central sleeve-like support portion (14) which protrudes axially inside the housing (10), whereby the outer surface of the central sleeve-like support portion (14) is configured to provide axial support for the elastic diaphragm (16) at least when the hydraulic rock breaker (43) is not pressurized; and The inner surface of the central sleeve-like support portion (14) of the flange element (13) is provided with a seal (23) for sealing the end portion of the piston (9) of the hydraulic rock breaker (43).

2. The hydraulic rock breaker according to claim 1, characterized in that The flange element (13) comprises an annular mounting portion (15) which is transverse to the axial direction of the pressure accumulator (8); and The pressure channel (20) is located at the annular mounting portion (15).

3. The hydraulic rock breaker according to claim 1 or 2, characterized in that: The edge (33) of the elastic membrane (16) is provided with at least one protrusion (34) at least on one side of the elastic membrane (16), and the at least one protrusion (34) serves as a sealing element; and At least one of the axial mounting surfaces between the housing (10) and the flange element (13) is provided with a groove (35) for receiving the at least one protrusion (34).

4. A hydraulic rock breaker according to any one of the preceding claims 1-2, characterized in that The axial length of the central sleeve-shaped support portion (14) of the flange element (13) is at least 1 / 4 of the axial length of the pressure accumulator (8).

5. A hydraulic rock breaker according to any one of the preceding claims 1 to 2, characterised in that The outer side surface (58) of the central sleeve-shaped support portion (14) of the flange element (13) is inclined toward the distal end of the central sleeve-shaped support portion (14), so that the central sleeve-shaped support portion (14) gradually tapers toward the distal end.

6. A hydraulic rock breaker according to any one of the preceding claims 1 to 2, characterised in that The closed end of the elastic diaphragm (16) includes a top surface portion facing the gas space (17), and the top surface includes an annular edge portion (56), a center portion (39), and an annular recessed portion between the annular edge portion (56) and the center portion (39).

7. A hydraulic rock breaker according to any one of the preceding claims 1 to 2, characterised in that The side wall (40) of the elastic diaphragm is angled relative to an axial centerline of the pressure accumulator (8) whereby the side wall (40) opens toward an open end (54) of the elastic diaphragm (16).

8. A hydraulic rock breaker according to any one of the preceding claims 1 to 2, characterised in that The hydraulic space (18) of the pressure accumulator (8) is connected to the hydraulic system of the percussion device (4), and pressure fluid is configured to flow to and from the hydraulic space (18) during operation of the percussion device.

9. A hydraulic rock breaker according to any one of the preceding claims 1 to 2, characterised in that The hydraulic rock breaker (43) further comprises at least one valve for regulating the pressure of the hydraulic fluid prevailing in the hydraulic system connected to the pressure accumulator (8).

10. A hydraulic rock breaker according to any one of the preceding claims 1 to 2, characterised in that The top end (22) of the piston (9) facing the hydraulic space (18) of the pressure accumulator (8) is rounded.

Images