Safety device and hydraulic component having housing

Abstract

The utility model relates to a safety device, comprising a screw body (10), which has a screw head (36), which is integrally connected to the screw body, as a rotational drive part, and which has a thread (30), which is integrally connected to the screw body, as a fastening part, and which has a bursting device (12), which is arranged in a channel (16) of the screw body (10), the sight glass (20) is completely received as an inspection device (14) together with the bursting device (12) in the channel (16) of the screw body (10) for identifying the state of the bursting device (12). The disclosure also relates to a hydraulic component having a housing with such a safety device. The utility model relates to a safety device, by means of which it is ensured that the bursting device breaks as a safety element when a predefinable pressure limit value is exceeded, as a result of which the channel of the fastening device is filled with a fluid until an inspection device arranged opposite the bursting device "responds" and notifies a failure situation.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of safety equipment and a hydraulic component with shell. BACKGROUND

[0002] It is known from DE102015014797A1 a safety device with a coupling point for a pressure accumulator, which is connected on the gas side with a burst device by the coupling point, which burst device allows the pressure accumulator to be emptied on the gas side in a triggered state triggerably by means of a force element that can be actuated.

[0003] Here the pyrotechnic object can be used as force element, which, upon ignition of the detonation charge at the corresponding point, deforms or destroys the wall block of the housing so that the burst device received therein is triggered, or which destroys the burst disc of the burst device by means of a handling pin. Thereby the possibility is opened to react to a dangerous situation, such as in a fire situation, by means of a pressure reduction before a dangerous overpressure, such as caused by overheating in a fire situation, can occur. Ultimately the coupled hydraulic circuit together with its components will not be able to function in response to the safety device here. SUMMARY

[0004] Therefore, starting from the prior art, the utility model is based on the following task: to propose a comparable safety device, the coupled hydraulic circuit together with its components remains normal working in response.

[0005] The safety device, which comprises a screw body with a screw head connected in one piece with the screw body as a rotary drive part and with a thread connected in one piece with the screw body as a securing part and with a bursting device arranged in a channel of the screw body, in which a sight glass as a checking device is completely received together with the bursting device in the channel of the screw body for identifying the state of the bursting device, ensures that, upon exceeding a predefinable pressure limit value, the bursting device breaks as a safety element, as a result of which the channel of the securing device is filled with fluid until the checking device arranged opposite the bursting device "responds" and reports the failure situation. In this way, it is possible in a relatively simple manner to determine that, for example, in a hydraulic circuit together with its coupled components, an overpressure occurs which is harmful in certain cases for the hydraulic valve, which leads to the bursting of the bursting device, and then the checking device provides an indication to the operator or maintenance personnel about the occurrence of the undesired overpressure or overload situation, without the function of the coupled hydraulic system being lost or being negatively affected in any other way. The cover for the bursting device and the checking device is made from a single piece, in particular from a metal material, and is therefore high-strength. In this regard, there is no occurrence of sealing problems, which would lead to undesired leaks. The safety device can also be permanently fixed in or at third-party structural components, such as valve blocks, fluid couplings, etc.

[0006] In a preferred embodiment of the safety device according to the application, it is provided that the bursting device has a bursting disc which is fixedly connected to the screw body in the channel of the screw body as a separate component, in particular welded along the outer peripheral line of the bursting disc. The bursting disc is usually composed of a thin-walled metal film, also of a corrosion-resistant stainless steel material, the film thickness of which is selected in such a way that the film or the bursting disc fails at a predefinable overpressure threshold. Due to the linear connection seam, the bursting disc is fixed on the edge side in a comparable manner to a diaphragm and is thus designed as a kind of free vibrating element, which is relieved of load when a corresponding pressure load occurs, also in the form of vibrations.

[0007] If the checking device is formed by a sight glass, this allows a determination of whether the bursting device has failed by a simple visual check in such a way that the hydraulic medium enters the channel of the securing device just through the burst bursting disc, which is visually determinable from the outside via the sight glass. Since the hydraulic fluid is usually dyed, for example with a red color, the failure situation can be determined visually accurately even in difficult ambient light situations.

[0008] The checking device itself can also be formed by an ultrasonic probe, or contain a capacitive measuring device, or have a sensor system for determining the electrical conductivity; only such checking or detecting devices require an electric current for evaluation and information transmission, which from a safety point of view is not always considered advantageous in conjunction with a flammable hydraulic medium, so that in any case a visual check without electric current meets the heightened safety requirements. In particular, the safety device according to the application is so self-stable that no additional outflow channel is required on the housing side. In particular, the safety device according to the application is so self-stable that no additional outflow channel is required on the housing side. This is not the case in the prior art. The rupture disc almost seamlessly transitions into the securing device and is so reliably anchored with the securing device that it thus covers the input channel in a pressure-tight manner.

[0009] It has proven advantageous in order to realize a particularly safe function that the rupture disc covers (überspannen) the free end of the channel on the inside, which is adjacent to the thread end, which is arranged on the side of the screw body facing away from the screw head. The rupture disc is preferably provided with a curvature starting from the fixing point of the rupture disc in the channel of the screw body, which bulges in the direction of the sight glass. In this way, a safe fluid guidance in the direction of the deepening protrusion is ensured in the case of a uniform force introduction for the rupture case, so that failure cases can be reliably taken into account and the rupture disc breaks or fails at a precisely defined limit value.

[0010] It is furthermore preferably provided that the channel is formed by a hollow-cylindrical recess in the screw body, which remains constant in diameter completely through the screw body and leads out into the surroundings at the free, opposite ends of the screw body. The diameter of the rupture disc and the diameter of the sight glass, which is preferably configured as a cylinder, are identical. Due to the constant channel diameter, pressure peaks cannot inadvertently be built up in the channel, which can act disadvantageously in the case of a failure.

[0011] In a particularly preferred embodiment it is provided that the sight glass is configured as a solid cylinder, which ends in the inserted state in the channel flush with the upper side of the screw head and thus has an insertion length in the channel such that the sight glass ends flush with the (lower) side of the screw head at the height of the dummy extension, which (lower) side of the screw head is adjacently opposite the other end of the thread. Thereby an own closed body with a symmetrical structure and a uniform pressure distribution in the case of damage is created.

[0012] In a further preferred embodiment of the safety device according to the application it is provided that the sight glass consists of a glass material, such as composite safety glass, soda-lime glass, borosilicate glass, glass ceramic or quartz glass or sapphire glass. The selection of the possible glass material enables a targeted selection of the sight glass in terms of pressure resistance, temperature resistance, transparency and material resistance with respect to the liquids and / or gases occurring in the hydraulic circuit for the respective application. In particular, the aforementioned glass types can be ground at their exposed end side for better optical properties and are preferably polished during this time. In this regard, disturbing scratches and unevennesses are eliminated and a visually appealing and, if necessary, easily cleanable surface is created. In this way, the use of the sight glass is maintenance-free and allows a reliable visual inspection of the interior of the channel within the fixture. Furthermore, the sight glass can also be provided with visual properties, such as magnifying sections, protective layers and / or prism properties. The use of borosilicate glass has proven particularly advantageous in this regard.

[0013] In a further particularly preferred embodiment of the safety device according to the application it is provided that the fixture consists of a metal material, such as corrosion-resistant stainless steel, which surrounds the glass material, both the metal material and the glass material being heated together in the context of the manufacture to a temperature at which the glass material is in a liquid state and accumulates at the metal material in the case of a latching therewith, so that upon subsequent cooling the glass material solidifies within the channel of the fixture and is clamped annularly by the metal material of the fixture. This enables a fluid-tight installation of the sight glass into the fixture, wherein a force-locking connection is configured between the glass material of the sight glass and the metal material of the fixture. By means of the mechanical pre-tension, the sight glass thus fused with the metal behaves like a ductile material and has an increased safety compared to a sight glass which is otherwise thermally pre-tensioned. In some embodiments, the screw body consists of a metal material, which surrounds the glass material of the sight glass, the metal material and the glass material being heated together to a temperature at which the glass material is in a liquid or paste-like state and accumulates at the metal material in the case of a latching therewith, so that upon subsequent cooling the glass material solidifies within the channel of the screw body and is clamped annularly by the metal material.

[0014] The respective sight glass is integrated in the form of an embedded solution in the screw insert, and such a screw insert can be produced in a standardized constructional manner in large numbers and can also be used as a retrofit component in an already existing delivered hydraulic installation as required in this regard.

[0015] It has proven to be particularly functional and reliable if the sight glass ends flush with the upper side of the active portion, wherein the sight glass has a joining depth in the passage which is equal to or greater than the diameter of the sight glass in a manner constructed as a solid, pressure-tight cylinder. This ensures a particularly pressure-tight anchoring of the sight glass in the screw-in portion.

[0016] For a functionally reliable detection, the free length of the passage in the screw-in portion is selected to be greater than or equal to the length of the outer thread of the screw-in portion, which concentrically surrounds the passage designed in a hollow-cylindrical manner, which receives the hydraulic medium after failure of the burst disc, until it abuts against the lower side of the sight glass and in this respect informs the failure situation to the sight glass as a visual checking device.

[0017] The subject of the utility model is also a hydraulic component, preferably as an assembly of an entire hydraulic installation, which has a housing, in which at least one pressure-guiding fluid passage extends, wherein the safety device presented above establishes a fluid-guiding connection between the burst device and the pressure-guiding passage in the housing in a manner fixed in the housing in a pressure-tight manner, such that the burst device ruptures when a pressure threshold value which is critical to safety is exceeded in the fluid passage, and in accordance with this the fluid introduced into the safety device can be determined by a checking device, in particular a detection device in the form of a sight glass, so that an overload situation, which can also include a failure situation, can thus be directly detected. BRIEF DESCRIPTION OF DRAWINGS

[0018] The safety device is explained in detail below with the aid of an embodiment according to the drawings. Herein in a diagrammatic and not to scale illustration:

[0019] Figure 1 A perspective top view of the safety device is shown overall;

[0020] Figure 2 A longitudinal sectional view through the safety device according to Figure 1 is shown;

[0021] Figure 3 A perspective top view of a hydraulic component is shown, which has a safety device according to Figure 1 and Figure 2 placed in from the upper side; and

[0022] Figure 4 A longitudinal sectional view through the hydraulic component according to Figure 3 is shown. DETAILED DESCRIPTION

[0023] Figure 1 The safety device is shown overall in a perspective view. The safety device has a fixing device in the form of a screw body 10, which has a burst device 12, which ruptures in the direction of the Figure 1The fixing device is additionally provided with a checking device 14 on its upper side. Figure 2 As shown in the longitudinal section of FIG, there is a tubular passage 16 in the screw body 10, which is directed toward Figure 2 The screw body 10 is delimited on its lower side by the bursting device 12 and on its upper side by the inspection device 14, which are arranged at a predeterminable axial distance from each other when viewed in the direction of sight. The screw body 10 includes a screw head 36 integrally connected thereto as a rotational drive part for actuation by an operating tool (not shown in detail). The screw body 10 also has a thread 30 integrally connected thereto as a fixing part for installation in the housing 42.

[0024] The bursting device 12 is an annular bursting disc 18, and the inspection device 14 is formed by a plug-shaped sight glass 20, which is inserted flush outwardly into the channel 16. The annular bursting disc 18 is fixed to the fixing device at the end on the free end side of the channel 16, preferably welded accordingly along the annular connecting portion 22. In addition, the bursting disc 18 has a projection extending convexly from the outside to the inside as a bend 24, which extends into the channel 26 symmetrically with respect to the longitudinal axis 26 of the fixing device, wherein the projection or bend 24 ends flush with the free end side of the channel 16 on the edge side and thus transitions in one piece into a flat contact surface 28 of the bursting device 12, which is connected according to the embodiment of the present invention. Figure 2 The illustration of extends in a horizontal plane transverse to the longitudinal axis 26 .

[0025] The projection is ultimately a part of the bursting device 12 which is the component that bursts in the event of an overload or failure. At the location of the annular weld 22, the contact surface 28 of the bursting disk 18 opens into the upwardly adjoining threaded section 30, so that the fastening device as a whole is designed in the manner of a fastening screw 32 with the threaded section 30 as the actual screw-in part 33 in the form of an external thread 34, which is Figure 1 For the sake of simplicity, the illustration is not reproduced in detail. Furthermore, the fixing screw 32 has a hexagonal engagement portion 36 on the head side, adjacent to the screw-in portion 33, for engagement with an assembly tool (not shown in detail), such as a wrench of the appropriate nominal size. As is common in such fixing screws 32, the head-side engagement portion 36 projects beyond the foot-side screw-in portion 33 on the periphery. In the direction of the engagement portion 36, the threaded section 30 or external thread 34 opens into a circumferential groove 38, which is used to accommodate a sealing element, such as a copper sealing ring (not shown). The screw body 10 is designed in a compact form, i.e., the nominal width of the screw head 36 corresponds essentially to the total overall height of the fixing screw 32, resulting in a cubic structure that can withstand particularly high pressures.

[0026] The sight glass 20 consists of a glass material, preferably borosilicate glass, wherein, in order to establish a connection 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 is liquid and, while in contact with the screw body, accumulates on the metal material of the screw body 10, so that upon subsequent cooling, the glass material solidifies in the channel 16 of the screw body 10 and is clamped in a defined manner by the metal material and thus fixed in a defined manner. Figure 1 and Figure 2 It also turns out that the sight glass 20 ends flush with the upper side of the active part 36 and that the sight glass 20 is designed as a solid glass cylinder and has an engagement depth in the channel 16 that is slightly greater than the free diameter of the sight glass 20 .

[0027] In order to enable the screw body 10 to receive a corresponding amount of fluid after the bursting device 12 has burst, the free length of the channel 16 in the screw-in part 33, viewed in a direction parallel to the longitudinal axis 26, is selected to be greater than the external length of the external thread 34 of the screw-in part 33, which in this respect concentrically surrounds the hollow cylindrical channel 16.

[0028] The safety device explained above is particularly suitable for installation in any type of hydraulic component provided with at least one pressure-conducting fluid channel 40. By way of example and for simplicity of presentation, Figure 3 and Figure 4 In the figure, such a hydraulic component is reproduced as a cuboid housing 42, with a fluid channel 40 extending along its longitudinal axis 44. The housing 42 can have two fluid connections, for example in the form of a fluid inlet 46 and a fluid outlet 48. Both the inlet 46 and the outlet 48 are provided with internal threads 50, which respectively enable the connection of lines (not shown in detail) of the hydraulic circuit to hydraulic components such as, for example, a pressure supply pump, a hydraulic accumulator, a valve arrangement, hydraulic consumers such as actuators, etc.

[0029] So outside Figure 3 and Figure 4It is derived that the safety device with the screw body 10 is arranged centrally at the center of the housing 42, wherein the action portion 36 can be flushly partially screwed into the recess 52 on the upper side of the housing 42. The safety device component designed as a screw-in portion 33 is screwed with its outer thread 34 into a mating inner thread 56 in the upper housing wall 54 of the housing 42, wherein the inner thread 56 is configured with a longer thread section than the mating outer thread 34 of the securing device. In particular, the lower end of the securing device with the burst disc 18 is received in the upper housing wall 54 slightly recessed in the radial direction, transverse to the longitudinal axis 44, relative to the fluid channel 40. Here, the lower side of the screw head 36 is directly supported at the housing wall 54, which contributes to a reliable anchoring of the screw body 10 in the housing 54.

[0030] If an undesired fluid pressure rise now occurs in the fluid channel 40, which can be sufficient, for example, to possibly damage a coupled valve device (not shown), such as a pressure-limiting valve, the burst disc 18 breaks due to bursting or due to tearing, and the channel 16 is filled with fluid, for example in the form of a colored hydraulic medium, such as a transmission oil. In the context of a predefined inspection interval, an operator or maintenance personnel can then determine by visual inspection at the sight glass 20 that the channel 16 is full of fluid, which can only be the case when the burst disc 18 has broken, and the burst disc in turn only breaks when an unallowably high pressure rise is present in the system, such as possibly even only for a short time. It can be decisive in this notification situation whether the person carries out a more careful inspection of the valve device or whether the valve device is immediately replaced. In contrast to this, such an inspection cannot be carried out with the safety device in the prior art.

Claims

1. A safety device, characterized in that: The safety device comprises a screw body (10), the screw body having a screw head (36) integrally connected to the screw body as a rotation drive part, and the screw body having a thread (30) integrally connected to the screw body as a fixing part, and the screw body having a bursting device (12) arranged in a channel (16) of the screw body (10), wherein a sight glass (20) as an inspection device (14) is completely received in the channel (16) of the screw body (10) together with the bursting device (12) for identifying the status of the bursting device (12).

2. The safety device according to claim 1, characterized in that The bursting device (12) comprises a bursting disc (18), which is fixedly connected to the screw body in a channel (16) of the screw body (10) as an independent component.

3. The safety device according to claim 2, characterized in that The bursting disc (18) covers the free end of the channel (16) on the inside, the free end being adjacent to the thread end which is arranged on the side of the screw body (10) facing away from the screw head (36).

4. The safety device according to claim 2, characterized in that The bursting disc (18) is provided with an arch (24) starting from the fixing position of the bursting disc in the channel (16) of the screw body (10), and the arch protrudes in the direction of the sight glass (20).

5. The safety device according to any one of claims 1 to 4, characterized in that The channel (16) is formed by a hollow cylindrical recess in the screw body (10), which extends completely through the screw body (10) with a constant diameter and opens into the surroundings at the free, mutually opposite ends of the screw body.

6. The safety device according to claim 2, characterized in that The diameter of the bursting disc (18) is the same as the diameter of the sight glass (20).

7. The safety device according to any one of claims 1 to 4, characterized in that The sight glass (20) is designed as a solid cylinder and, in the inserted state, ends flush with the upper side of the screw head (36) in the channel (16) and has an insertion length in the channel (16) such that the sight glass ends with an imaginary extension flush at the height of one side of the screw head (36) which is adjacently opposite the other end of the thread (30).

8. The safety device according to any one of claims 1 to 4, characterized in that The screw body (10) is made of a metal material which surrounds the glass material of the sight glass (20). The metal material and the glass material are heated together to a temperature at which the glass material is liquid or pasty and accumulates on the metal material when in contact with the metal material, so that when subsequently cooled, the glass material solidifies in the channel (16) of the screw body (10) and is clamped in an annular manner by the metal material.

9. The safety device according to any one of claims 1 to 4, characterized in that The sight glass (20) is made of glass material.

10. The safety device according to claim 2, characterized in that The bursting disc is fixedly welded to the screw body along the outer peripheral line of the bursting disc (18) in the channel (16) of the screw body (10).

11. The safety device according to claim 6, characterized in that The sight glass is cylindrical in design.

12. The safety device according to claim 9, characterized in that The sight glass (20) is made of composite safety glass, soda-lime glass, borosilicate glass, glass ceramics, quartz glass or sapphire glass.

13. The safety device according to claim 7, characterized in that The sight glass (20) has such an insertion length in the channel (16) that it ends with a virtual extension flush at the level of a lower side of the screw head (36), which is adjacently opposite the other end of the thread (30).

14. A hydraulic component having a housing, characterized in that: At least one pressure-carrying fluid channel (40) extends in the housing, and the hydraulic component carries a safety device according to any one of claims 1 to 13, which is fixed in a pressure-tight manner in the housing (42) and, with the screw head (36) of the safety device resting on the housing (42), establishes a fluid-carrying connection (57) between the bursting device (12) and the pressure-carrying channel (16) in such a way that when a safety-critical pressure threshold is exceeded in the fluid channel (16), the bursting device (12) breaks and the fluid introduced into the safety device can be detected by means of a sight glass (20).

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