Safety device

Abstract

A safety device comprising a screw body (10) having an integrally coupled screw head (36) as a rotational drive part, an integrally coupled screw part (30) as a fixed part, and a rupture device (12) disposed within a passage (16) of the screw body (10), wherein a sight glass (20) as an inspection device (14) for evaluating the state of the rupture device (12) is completely housed within the passage (16) of the screw body (10) together with the rupture device (12).

Description

【Technical Field】 【0001】 The present invention relates to a safety device. 【Background Art】 【0002】 According to Patent Document 1, a safety device having a connection portion for a pressure accumulator is known, and the pressure accumulator is connected to a rupture device on the gas side via this connection portion, and the rupture device is operable via a drivable force member, and in the actuated state, it enables the discharge of the gas side of the pressure accumulator. 【0003】 As the force member, an explosive object is used, and when the propellant is properly ignited, the object deforms or destroys a wall piece of the housing to operate the rupture device housed therein, or destroys the rupture disk of the rupture device by an operating pin. Thereby, for example, by reducing the pressure before a dangerous overpressure occurs due to overheating during a fire, the possibility of coping with a dangerous situation such as a fire is opened. Finally, due to the response of the safety device, the components of the connected hydraulic circuit stop functioning. 【Prior Art Documents】 【Patent Documents】 【0004】 【Patent Document 1】 German Patent Application Publication No. 102015014797 (A1) 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0005】 Therefore, an object of the present invention is to provide an equivalent safety device based on such prior art, in which the components of the connected hydraulic circuit can continue to function when the safety device responds. 【Means for Solving the Problems】 【0006】 This problem is solved by a safety device having the features of claim 1 as a whole. 【0007】 A safety device comprising a screw body having a screw head integrally coupled as a rotary drive part, a screw part integrally coupled as a fixed part, and a rupture device disposed within the passage of the screw body, wherein a sight glass as an inspection device for inspecting the state of the rupture device is completely housed within the passage of the screw body together with the rupture device, so that when a pressure limit value that can be determined in advance is exceeded, the rupture device as a safety member operates, and as a result, the passage of the fixing device is filled with fluid, and finally the inspection device attached opposite to the rupture device "responds" to report a defect. In this way, by means of relatively simple means, an overpressure that may be harmful in some cases, for example, to a hydraulic valve, occurs in a component connected in a hydraulic circuit, and as a result, the overpressure ruptures the rupture device, and the inspection device notifies an operator or a maintenance person of the occurrence of an undesirable overpressure or overload situation, but does not stop or damage the function of the connected hydraulic components. The sleeves for the rupture and inspection devices are extremely robust because they are integrally manufactured particularly from a metallic material. In that regard, there will be no sealing problems that cause undesirable leakage. Further, this safety device is permanently fixed to or within third-party components such as valve blocks, fluid connectors, etc. 【0008】 In a preferred embodiment of the safety device according to the present invention, the rupture device has a rupture disk, and the rupture disk is firmly coupled to the screw body as a self-standing component within the passage of the screw body, and is particularly firmly welded along the outer peripheral line of the rupture disk. The rupture disk is generally made of a thin metal membrane and also a noble metal material resistant to corrosion, and the membrane thickness is selected such that a defect occurs in the membrane or the rupture disk at a predetermined overpressure threshold value. Due to the joint seam being linear, the rupture disk is fixed at the edge side in the same manner as a vibrating membrane and is designed as a kind of cantilever, whereby even in the form of vibration, when an appropriate pressure load occurs, the load on the rupture disk is reduced. 【0009】 When the inspection device is formed of a sight glass, this sight glass enables easy visual confirmation of whether the rupture device has malfunctioned by the hydraulic medium flowing into the passage of the fixing device through the ruptured rupture disk, which is visually detectable from the outside through the sight glass. Often the hydraulic fluid is colored, for example, has a red color, so that even when the ambient light conditions are poor, the defect can be visually confirmed. 【0010】 The inspection device itself can also be formed by an ultrasonic detector, or can have a capacitive measuring device, or can also have a sensor technology for determining conductivity; however, such an inspection device or detection device requires an electric current for evaluation and information transmission, which is not necessarily considered preferable in cooperation with a combustible hydraulic medium from a safety perspective. Therefore, a visual inspection without the need for an electric current in each case takes into account such increased safety requirements. In particular, the safety device according to the present invention is self-stabilizing because no additional discharge passage is required on the housing side. In particular, the safety device according to the present invention is self-stabilizing because no additional discharge passage is required on the housing side. This is unprecedented in the prior art. The rupture disk has migrated to the fixing device almost seamlessly and is securely locked with the fixing device so as to be stretched over the inflow passage in a pressure-tight manner. 【0011】 In order to ensure the function particularly reliably, it has been clearly shown that it is preferable that the rupture disk is stretched over the inside of the free end of the passage, and this free end is adjacent to the threaded end portion of the threaded body, which is arranged on the side opposite to the threaded head. Preferably, the rupture disk has a raised portion starting from its fixed position in the passage of the threaded body and projecting in the direction of the sight glass. In this way, during rupture, a reliable fluid guide in the direction of the recess of the protrusion with a uniform introduction of force is ensured, so that malfunctions can be reliably considered, and the rupture disk deflects or breaks at a precisely defined limit value. 【0012】 Preferably, further, the passage is formed by a hollow cylindrical notch in the threaded body, the notch completely penetrates the threaded body without changing its diameter, and communicates with the surroundings at its free, opposite ends. The diameter of the rupture disk and the diameter of the sight glass, preferably formed in a cylindrical shape, are equal. Since the passage diameter is constant, no unwanted pressure peaks that could cause a negative effect in case of a malfunction are built up inside the passage. 【0013】 In a particularly preferred embodiment, the sight glass is formed as a solid cylinder and terminates in the same plane as the upper side of the screw head when inserted into the passage, and the insertion length it has in the passage is such that the sight glass, on a virtual extension, terminates in the same plane at the height of the (lower) side of the screw head, adjacent and opposite to the other end of the threaded portion. Thereby, a self - enclosed body with a symmetrical structure and a homogeneous pressure distribution in case of damage is produced. 【0014】 In another preferred embodiment of the safety device according to the invention, the sight glass is formed from a glass material, such as, for example, laminated safety glass, soda glass, borosilicate glass, glass ceramic, quartz glass or sapphire glass. The possible selection of the glass material makes it possible to select the sight glass as desired with respect to pressure stability, temperature stability, transparency and material stability with respect to the liquids and / or gases occurring in the hydraulic circuit, for each respective application. In particular, the exposed front side of the above - mentioned types of glass is polished for the improvement of the appearance and is preferably polished from time to time. To that extent, interfering scratches and irregularities are removed, forming a surface that gives a visually pleasing impression and can be easily cleaned if necessary. In this way, the use of the sight glass is maintenance - free and enables a reliable visual inspection within the passage inside the fixing device. Furthermore, the sight glass is provided with optical properties, such as magnification, coating and / or prism characteristics. Among other things, it has been shown that the use of borosilicate glass in this context is particularly preferred. 【0015】 In yet another preferred embodiment according to the present invention, the fixing device is formed from a metallic material, such as spring steel that is resistant to corrosion, and the metallic material surrounds the glass material. By heating both of them together within the manufacturing frame to a temperature at which the glass material becomes liquid and flows while adhering to the metallic material, and then cooling, the glass material hardens inside the passage of the fixing device and is clamped in a ring shape by the metallic material of the fixing device. In this way, the site glass is fluid-tightly incorporated into the fixing device, and at that time, a force-based bond is formed between the glass material of the site glass and the metallic material of the fixing device. The site glass thus melted by metal behaves like a ductile material under mechanical biasing and has higher safety compared to the thermally biased site glass in other cases. 【0016】 Each site glass is integrated by a certain type of insert melting within the screw insertion piece, and such screw insertion pieces are manufactured in large quantities with a standardized structure and can also be inserted later as a retrofit set into the hydraulic equipment that has already been installed. 【0017】 It has been clarified that it is particularly reliable functionally when the site glass terminates in the same plane as the upper side of the engagement part. The site glass is formed as a solid cylinder and has an entry depth in the passage that is equal to or greater than the diameter of the site glass. In this way, it is ensured that the site glass is particularly pressure-tightly locked within the screwing part. 【0018】 To make the inspection function more reliable, the free length of the passage within the screwing part is selected to be greater than or equal to the length of the external thread of the screwing part that concentrically surrounds the passage formed in a hollow cylindrical shape. The screwing part accommodates the hydraulic medium until it contacts the lower side of the site glass after the rupture disk fails, and in that regard, reports the occurrence of a malfunction to the site glass as a visual inspection device. 【0019】 Preferably, a hydraulic component as a component of the entire hydraulic equipment is also an object of the present invention. The hydraulic component has a housing, and at least one pressure transmission fluid passage extends therein. The safety device introduced above is fixedly secured in the component housing in a pressure-tight manner, and a fluid conveyance connection is established between the rupture device and the pressure transmission passage in the housing as follows: that is, when the safety-critical threshold pressure value in the fluid passage is exceeded, the rupture device operates, and the fluid flowing into the safety device accordingly can be confirmed, particularly by an inspection device in the form of a sight glass, so that an overload state that may occur due to a malfunction can be directly detected. 【0020】 Hereinafter, the safety device will be described in detail using the embodiments shown in the drawings. The figures are schematic and not to scale. 【Brief Description of the Drawings】 【0021】 【Figure 1】 Figure 1 shows the entire safety device in a perspective view from above. 【Figure 2】 Figure 2 shows the safety device shown in Figure 1 in a longitudinal sectional view. 【Figure 3】 Figure 3 shows the hydraulic component into which the safety device shown in Figures 1 and 2 is inserted in a perspective view from above. 【Figure 4】 Figure 4 shows the hydraulic component shown in Figure 3 in a longitudinal sectional view. 【Embodiments for Carrying Out the Invention】 【0022】 Figure 1 shows the entire safety device in a perspective view. The safety device has a fixing device in the shape of a screw body 10 equipped with a rupture device 12, and the rupture device is arranged at the lower end of the fixing device in the line-of-sight direction when looking at Figure 1. The fixing device further has an inspection device 14 on its upper side. As is clearly shown in the longitudinal sectional view particularly shown in Figure 2, a pipe-shaped passage 16 is provided inside the screw body 10, and the passage is defined by the rupture device 12 at the lower side and the inspection device 14 at the upper side in the line-of-sight direction when looking at Figure 2, and to that extent they are arranged at an axially defined interval relative to each other. The screw body 10 has an integrally coupled screw head 36 as a rotational drive part that engages with an operating tool (not shown in detail). Further, the screw body 10 has an integrally coupled screw part 30 as a fixing part for incorporation into the housing 42. 【0023】 The rupture device 12 is a ring-shaped rupture disk 18, and the inspection device 14 is formed from a plug-shaped sight glass 20, and the sight glass is inserted into the passage 16 so as to be flush with the outside. The ring-shaped rupture disk 18 is fixed to the fixing device at the end of the free end face of the passage 16, preferably welded appropriately along the ring-shaped joint 22. Further, the rupture disk 18 has a protruding part as a raised part 24 that extends convexly from the outside to the inside, and the raised part projects symmetrically into the passage 26 with respect to the longitudinal axis 26 of the fixing device. The protruding part or raised part 24 ends flush with the free end face of the passage 16 at the edge side, and thus transitions integrally to the flat abutting surface 28 of the rupture device 12. According to the view in Figure 2, the abutting surface extends horizontally in a plane transverse to the longitudinal axis 26. 【0024】 The protrusion is ultimately part of the rupture device 12, and that part is a component that ruptures in case of overload or malfunction. At the location of the ring-shaped weld seam 22, the abutting surface 28 of the rupture disk 18 communicates upward into the continuous thread section 30, so the fixing device is formed as a fixing screw 32 as a whole and has the thread section 30 as the original screwing part 33 in the form of an external thread part 34, but the external thread part is not shown in detail in FIG. 1 for simplification. Further, the fixing screw 32 continuously has a hexagonal-shaped engaging part 36 on the head side with respect to the screwing part 33, and that part is used for engagement with a mounting tool not shown in detail, such as a wrench of an appropriate standard size. As is common in this type of fixing screw 32, the outer peripheral side of the engaging part 36 on the head side projects beyond the screwing part 33 on the base side. In the direction of the engaging part 36, the thread section 30 or the external thread part 34 communicates into the circumferential groove 38, and the circumferential groove is used to accommodate a sealing means in the shape of, for example, a copper sealing ring (not shown). The screw body 10 is formed in a compact structure, that is, the nominal dimension of the screw head 36 substantially corresponds to the overall height of the fixing screw 32, so a certain cubic structure is formed, and that structure can particularly withstand high pressures. 【0025】 The sight glass 20 is made of a glass material, preferably borosilicate glass. In order to form a bond between the sight glass 20 and the metal material of the screw body 10, both the glass material and the metal material are heated to a temperature at which the glass material becomes liquid and flows while abutting against the metal material of the screw body 10. Then, when the glass material is cooled, the glass material hardens inside the passage 16 of the screw body 10 and is clamped in a ring shape by the metal material and fixed as determined in that way. Further, as is apparent from FIGS. 1 and 2, the sight glass 20 terminates in the same plane as the upper side of the engaging part 36, and the sight glass 20 is configured as a solid glass cylinder and has an engaging depth slightly larger than the free diameter of the sight glass 20 inside the passage 16. 【0026】 After the rupture device 12 ruptures, in order for the screw body 10 to be able to properly contain the fluid, in a direction parallel to the longitudinal axis 26, the free length of the passage 16 within the threaded portion 33 is selected to be greater than the length outside the external thread portion 34 of the threaded portion 33, and to that extent the threaded portion concentrically surrounds the passage 16 formed in a hollow cylindrical shape. 【0027】 The safety device described above is particularly suitable for incorporation into various types of hydraulic components having at least one pressure transmitting fluid passage 40. By way of example, and to simplify the illustration, this type of hydraulic component is shown in FIGS. 3 and 4 as a cuboid housing 42, and the fluid passage 40 extends along the longitudinal axis 44 of the housing. The housing 42 has two fluid connection points, for example in the form of a fluid inlet 46 and a fluid outlet 48. Both the inlet 46 and the outlet 48 have internal thread portions 50, and the internal threads enable connection of piping (not shown in detail) of a hydraulic circuit having a hydraulic component, such as a pressure supply pump, a hydraulic accumulator, a valve device, an actuator, etc. 【0028】 Furthermore, as is apparent from FIGS. 3 and 4, a safety device having a screw body 10 is attached at a central position on the housing 42, and in that case the engaging portion 36 can be partially screwed in the same plane into the upper notch 52 of the housing 42. The external thread portion 34 of the safety device component configured as the threaded portion 33 is screwed into a corresponding internal thread portion 56 within the upper housing wall 54 of the housing 42, and the internal thread portion 56 forms a screw section that is longer than the corresponding external thread portion 34 of the fixing device. In particular, the lower end of the fixing device having the rupture disk 18 is housed within the upper housing wall 54 so as to be slightly recessed with respect to the fluid passage 40 in a transverse direction with respect to the longitudinal axis 44, as seen radially. The lower side of the screw head 36 is directly supported by the housing wall 54, which helps to more securely lock the screw body 10 within the housing 54. 【0029】 Within fluid passage 40, in the event of an undesirable fluid pressure increase that may damage a connected valve device (not shown), such as a pressure limiting valve, rupture disk 18 yields by bursting or tearing, etc., and passage 16 is filled with fluid in the form of a colored hydraulic medium, such as gear oil. By an operator or maintenance personnel visually inspecting sight glass 20 within the defined inspection interval, it can be confirmed that passage 16 is filled with fluid, which can only occur when rupture disk 18 has actuated, and the rupture disk operates only when an unacceptably high pressure exists within the system, even if only for a short time. When such a report is made, it is possible to decide whether to inspect the valve device in detail or replace it immediately. In contrast, such an inspection was impossible with safety devices in the prior art.

Claims

[Claim 1] A safety device comprising a screw body (10), the screw body having a screw head (36) integrally coupled to the screw body as a rotational drive part, a screw portion (30) integrally coupled to the screw head as a fixed part, and a bursting device (12) disposed within a passage (16) of the screw body (10), wherein a sight glass (20) as an inspection device (14) for evaluating the state of the bursting device (12) is completely housed together with the bursting device (12) within the passage (16) of the screw body (10). [Claim 2] The safety device according to claim 1, wherein the bursting device (12) has a bursting disc (18), and the bursting disc is fixedly coupled to the screw body (10) as an independent component within the passage (16) of the screw body (10), and is particularly firmly welded along the outer circumference line of the bursting disc (18). [Claim 3] The safety device according to claim 2, characterized in that the burst disc (18) is stretched across the inside of the free end of the passage (16), and the free end is adjacent to the screw end portion of the screw body (10) that is located on the side opposite to the screw head (36). [Claim 4] The safety device according to claim 2, characterized in that the burst disc (18) has a raised portion (24) that starts from a fixing point in the passage (16) of the screw body (10), and the raised portion protrudes in the direction of the sight glass (20). [Claim 5] The safety device according to claim 1, characterized in that the passage (16) is formed by a hollow cylindrical notch in the screw body (10), the notch completely penetrates the screw body (10) while maintaining an equal diameter, and communicates with the surroundings at its opposite free ends. [Claim 6] The safety device according to claim 2, characterized in that the diameter of the burst disc (18) is equal to the diameter of the sight glass (20), which is preferably formed in a cylindrical shape. [Claim 7] The sight glass (20) is formed as a solid cylinder and, when inserted into the passage (16), terminates flush with the upper side of the screw head (36). The safety device according to claim 1, further characterized in that, within the passage (16), the virtual extension of the sight glass has an insertion length that terminates flush with the height of the (lower) side of the screw head (36), adjacent to and facing the other end of the screw portion (30). [Claim 8] The safety device according to claim 1, wherein the screw body (10) is formed from a metal material, the metal material surrounds the glass material of the sight glass (20), and together they are heated to a temperature at which the glass material becomes liquid or paste-like and flows in contact with the metal material, and subsequently cooled, the glass material hardens inside the passage (16) of the screw body (10) and is held in a ring shape by the metal material. [Claim 9] The aforementioned sight glass (20) is - Composite safety glass - Soda glass - Borosilicate glass - Glass ceramic, or - Quartz glass or sapphire glass The safety device according to claim 1, characterized in that it is formed from a glass material, such as the one described above. [Claim 10] A hydraulic component comprising a housing (42) having at least one pressure-transmitting fluid passage (40) inside, and a safety device according to any one of claims 1 to 9, wherein the safety device is compressed and fixed within the housing (42), and a fluid transport connection (57) is formed between the burst device (12) and the pressure-transmitting fluid passage (16) by the screw head (36) attached to the housing (42), and the burst device (12) is activated when the pressure in the pressure-transmitting fluid passage (16) exceeds a safety-critical pressure threshold, making the fluid flowing into the safety device detectable through the sight glass (20).

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