Rapid air valve for pneumatic use

Description

The invention is a quick-release valve for pneumatic use. Pneumatically operated equipment, machines, such as cylinders, pneumatically operated tools are usually supplied with compressed air via rigid or flexible pressure pipes, pressure lines, which are part of a compressed air supply system. In such a system, it often happens that the pneumatic equipment needs to be vented, for example when the pressure in the compressed air system is reduced by means of a pressure reducer. According to the applicant's knowledge, venting is usually carried out by means of a valve built into the pressure line, which is operated when necessary. However, this method is relatively complicated and, due to the small outflow cross-section, the venting process takes a long time. The object of the invention is therefore to provide a quick-release valve which, in simple operation, provides a large flow cross-section for air release.The invention is therefore a quick-release valve for pneumatic use. According to the invention, the quick-release valve is characterized by an inlet and an outlet for compressed air, which are in flow connection with each other via a main channel, in which a check valve is inserted, which allows the flow of compressed air from the inlet to the outlet and prevents the backflow of compressed air in the opposite direction, which divides the main channel into a first channel section that can be placed under inlet pressure and a channel section that is under outlet pressure, and further characterized by a venting channel in connection with the outlet channel section, in which an automatically operated shut-off valve is connected, which has a closing member that can be switched between an open venting position that allows the flow of the venting channel and a closed position that prevents the flow of the venting channel, which is in operative contact with two actuating surfaces directed opposite to each other,one of which is constantly acted upon by the inlet pressure on the actuating surface acting in the closing direction and by the outlet pressure on the actuating surface acting in the opening direction, and thus the closing member is in a switching position resulting from the pressure difference., In this way, the quick-release valve automatically closes or opens the venting channel depending on the pressure change, i.e. the difference between the inlet pressure and the outlet pressure. The two actuating surfaces working together with the closing member act as a pressure balance for the inlet and outlet pressures, while the operation of the shut-off valve can be influenced by the appropriate selection of the surface conditions. The surface conditions should be selected in such a way that the venting channel is closed as long as the inlet pressure is greater than or equal to the outlet pressure, while in the event of the inlet pressure falling below the outlet pressure, the shut-off valve switches to the venting position.As a result of the subsequent discharge of compressed air - namely through the venting port - the pressure on the inlet side decreases and when a lower limit value is reached, the shut-off valve switches back to the closed position. The associated check valve prevents the compressed air from flowing back towards the inlet side, so that it can only flow out through the venting port. This venting port can have a large cross-section to ensure rapid venting. Preferred embodiments of the invention are described in the subclaims. In a preferred embodiment of the invention, the actuating surfaces are arranged at least partially on a flexible solid membrane extending between the closure member and the valve housing. This membrane provides a reliable seal between the closure member and the valve housing without affecting the movement of the closure member. The closing element is preferably designed as a pressure-compensated seat element, while a mechanical closing spring is also preferably present, which presses the closing element in the closing direction. This closing spring advantageously provides support for overcoming the friction, which friction is produced by an advantageously annular seal, which seal is arranged between a guide cutout on the valve housing side and a guide piston which is displaceably guided therein. A particularly compact design is achieved if the check valve and the shut-off valve are arranged in a common valve housing, which can also be designed in several parts. This valve housing is preferably provided with a cut-out in the area of ​​the discharge side of the venting channel for the connection of a functional unit, so that, for example, an oil separator or a silencer or even a connecting air line can be connected to the valve housing. It is particularly advantageous to connect the quick-release valve according to the invention to a so-called control unit, i.e. to a device that is installed in a compressed air network for the production of compressed air. The invention is described in detail with reference to exemplary embodiments based on the drawings, where the Figure 1 is a drawing of an exemplary embodiment of a quick-deaeration valve according to the invention for installation in a treatment device, Figure 2 is a larger scale drawing of detail II indicated by dotted lines in Figure 1. In Figure 1, we start with a treatment device 1 for producing compressed air, which is connected to a compressed air line 2, indicated by dotted lines. A specific embodiment of the treatment device 1 is an air deoiler, which has a filter device 3 acting as an oil separator and is intended to separate oil particles from the air. This means that the discharged air can enter the environment without oil contamination. The treatment device 1 has, as an essential part, the quick-deaeration valve 4, which has a valve housing 5, to which an operating element 7 is attached at an intersection 6. HU 220 929 Β1 roof unit is detachably connected. In this embodiment, this is an 8 oil separator. The valve housing 5 according to the embodiment has a multi-part block-like structure. The valve housing has an inlet 12 connected to a section 14 of the compressed air line 2 and an outlet 13 connected to a further section 15 of this compressed air line 2. The section 14 is connected, for example, to a compressed air source 16, while a pressure reducer 17 is interposed, with which the pressure prevailing at the inlet 12 can be adjusted as required. The further section 15 can, for example, lead to one or more connection points, not shown in more detail, to which pneumatic consumers can be connected, and control valves, not shown, can optionally be interposed. In the valve housing 5, the inlet 12 can be connected to the outlet 13, for example by means of a straight main channel 18. A check valve 22 is inserted in its course. It has a closing member 23, which can be moved in the longitudinal direction of the channel, and which is biased in its closed position above the dotted longitudinal axis 21 in FIG. 1 by means of a return spring 24. In this closed position, it rests on our valve 26, which surrounds the main channel 18 in the form of a ring, with a seal 25. By means of the check valve 22, the main channel 18 is divided into an inlet-side channel section 27 and an outlet-side channel section 28. The check valve 22 is designed so that the flow of pressure medium in the main channel 18 from the inlet 12 to the outlet 13 is uniform, as long as the closing member 23 is lifted from our valve 26, which occurs when the inlet-side pressure or the force exerted by the pressure is greater than the outlet-side pressure and the force exerted by the return spring 24. Conversely, the check valve 22 prevents the return flow of compressed air in the opposite direction when the closing member 23 is pressed against our valve 26, which occurs when the outlet-side pressure is greater than the inlet-side pressure.The return spring 24 is intended to ensure stable switching states of the check valve 22 if it is arranged downstream of the closing member 23 in the outlet-side channel section 28 and is supported there between the closing member 23 and a support part 33 connected to the housing. The closing member 23 has several guide rails 34 extending in the axial direction and displaceably resting on the inner circumference of the main channel 18, while there is always a space 35 between the guide rails 34 adjacent in the circumferential direction, which ensures an unobstructed flow of compressed air when the check valve 22 is open. The outlet-side channel section 28 of the main channel 18 is connected to a venting port 36, which leads into a venting channel 37 opening into the intersection 6 of the valve housing 5. Along this venting channel 36, an automatically actuated shut-off valve 38 is arranged, which, like the check valve 22, is integrated into the valve housing 5 and thus forms a compact structural unit. The shut-off valve 38 divides the venting channel 36 into a channel section 42 communicating with the outlet-side channel section 28 of the main channel 18 and an outlet-side channel section 43 leading into the venting channel 37. The shut-off valve 38 has a valve 44 connected to the housing concentrically surrounding the venting port 36, to which a closing element 47 is assigned, which can be switched between a closed position 45 and an open venting position. In FIG. 2, the closing position 45 is shown to the left of the longitudinal axis 48 of the closing element 47, which coincides with the switching direction. Here, the closing element 47 rests sealingly on the valve seat 44 with an annular sealing portion 50 on the front face 49. In the venting position 46, which is shown to the right of the longitudinal axis 48, the closing element is raised from the valve seat 44 and leaves the port passage free. The closing element 47 is preferably designed as a seat element, as can be seen. For example, the valve seat 44 is arranged on the free end face of a housing-side projection 53 extending coaxially into the fluid chamber 51 of the valve housing 5. In this way, the mouth of the outlet-side channel section 44 surrounded by our valve is concentrically surrounded by a substantially annular fluid chamber 51. The fluid chamber 51 forms the end region of the inlet-side channel section 42, which is in permanent communication with the outlet-side channel section 28. Between the movable closing member 47 and the valve housing 5, a membrane 56 is arranged, preferably concentrically to the closing member 47, made of a flexible sealing material. This membrane 56, together with the closing member 47, forms a movable wall for the fluid chamber 51. In addition, the membrane 56 defines a control chamber 57 on its side opposite the fluid chamber 51, which is connected to the inlet-side channel section 27 of the main channel 18 by means of a control channel 58 arranged in the valve housing. The membrane 56 ensures an airtight seal between the control chamber 57 and the fluid chamber 51 without affecting the mobility of the closing member 47. Since the diaphragm 56 is statically fixed with its radially inner and radially outer ends to the closure member 47 and to the valve housing 5 on the other hand - in particular by clamping - the seal is very reliable and frictionless. The side or surface of the membrane 56 facing the control chamber 57 forms, according to the exemplary embodiment, an actuating surface 59 effective in the closing direction, which is under the influence of the inlet pressure prevailing in the main channel 18 via the control chamber 57 and the control port 58. This pressure is independent of the current position of the closing member 47. An actuating surface 62 is provided opposite the aforementioned actuating surface 59 and is effective in the opening direction of the shut-off valve 38. This is formed by the surface of the diaphragm 56 and the surface of the closing element 47 facing the closing direction 63 of the closing element 47, which in the closed position delimit the fluid chamber 51. In the exemplary embodiment, this is made up of the surface of the diaphragm 56 and the surface section of the closing element 47 lying radially outside the valve seat. The aforementioned actuating surface 62, which is effective in the opening direction, is constantly under the influence of the outlet pressure of the main channel 18 via the inlet-side channel section 42 of the venting channel 36. HU 220 929 Bl In this way, the actuating surfaces 59, 62 arranged opposite each other practically form a pressure balance, which is responsible for the current switching position of the closing member 47. The current switching position of the closing member 47 depends on the relationship between the two actuating surfaces 59, 62, i.e. the pressures, namely the relationship between the inlet pressure and the outlet pressure. In the exemplary embodiment, the actuating surface 59 of the shut-off valve 38, which is effective in the closing direction, is slightly larger than the actuating surface 62, which is effective in the opening direction. As a result, with the same inlet and outlet pressures, a small residual force acts on the closing member 47 in the closing direction 63, which holds the closing member 47 in the closed position. Due to the relationship of the actuating surfaces 59, 62 chosen in the exemplary embodiment, it was achieved that the shut-off valve 38 closes the venting port 36 until the inlet pressure in the inlet-side channel section 27 is greater than or equal to the pressure in the outlet-side channel section 28. In the event of a sufficiently large pressure difference, flow occurs from the inlet 12 to the outlet 13 through the main channel 18. However, as soon as the outlet pressure exceeds the inlet pressure due to operational conditions, for example due to a decrease in the inlet pressure, a compressive force is exerted on the closing member 47 in the opening direction 64 via the two actuating surfaces 59, 62, at which point it switches to the venting position and the compressed air can flow out of the outlet-side channel section 28 via the venting port 37 and its venting port 37, or out of the valve housing 5.This reduces the initial pressure, i.e. the pressure in the downstream section 15, until it reaches the inlet pressure level again. The non-return valve 22, which is closed during the venting phase, prevents air from flowing back into the section 14 of the compressed air line 2 and into the equipment connected to this line. In the closed positions of the shut-off valve 38, the outlet-side channel section 36 is closed by a closing surface 65 on the aforementioned end face 49 of the shut-off valve 47. This closing surface 65 is under the influence of the pressure prevailing in the channel section 42 of the venting channel 36 in the venting position 46. In order that this does not adversely affect the desired mode of operation of the shut-off valve, the closing element 47 has a compensation surface 66 directed opposite to the closing surface 65 and thus pointing in the opening direction 64. If a compensation channel 67 penetrates the closing element 47, preferably coaxially, and opens out at the compensation surface 66 at the other end, the two aforementioned surfaces are exposed to the same pressure. If the compensation surface 66 is at least substantially the same as the closing surface 65, then no significant compressive forces arise in the respective position of the closing member 47.This ensures that the shut-off valve 38 is operated solely as a function of the current pressure difference, namely in accordance with the relationship between the inlet pressure and the outlet pressure, and accordingly the shut-off valve 38 is automatically switched as a function of the current pressure conditions. The closing element 47 advantageously has a particularly cylindrical continuous guide piston 68 in its end region axially opposite the closing surface 65. The free end face of this guide piston 68 forms the compensation surface 66. By means of this guide piston 68, which is arranged in a longitudinally displaceable manner in the guide cutout 69 of the valve housing 5, the closing element 47 is guided stably relative to the valve housing 5. In order to prevent compressed air from flowing between the contact surface between the guide piston 68 and the guide cutout 69 and the compensation chamber 70 connected to the side of the control chamber 57 and bounded by the compensation surface 66, an annular seal 71 is preferably arranged between the guide piston 68 and the guide cutout 69. This is preferably seated in a circumferential groove of the guide piston 68. To compensate for the friction caused by the seal 71, a closing spring 74 is additionally arranged in the compensation chamber 70, which is supported on the valve housing 5 on the one hand and on the guide piston 68 on the other hand and thus biases the guide piston 68 - including the closing member 47 - in the closing direction 63. This is important, for example, as long as the compensation surface 66 is slightly smaller than the closing surface 65. Instead of the diaphragm 56, another actuator can also be used, for example a piston which is guided movably in the switching direction on the wall of the fluid chamber 51. The friction which still occurs due to the sealing required here is somewhat greater than in the case of the diaphragm. The compact design of the quick-release valve 4 also has the special advantage that it is always automatically actuated by the prevailing pressure conditions without manual intervention. Due to the correspondingly large cross-section of the air release channel 36, when the shut-off valve 38 is open, the excess compressed air can escape, and thus a practically automatic quick-release valve is available. The compressed air discharged or discharged via the venting port 36 can be treated as required. For example, this treatment can be the deoiling of the discharged air. For this reason, an oil separator 8 is connected to the device at the intersection 6, the filter device 3 of which is connected to the venting port 37. Thus, the exhaust air flows through the filter device 3 in the direction of the arrow 75 and is discharged cleanly from the shell-shaped or vessel-shaped housing 77, which houses the filter device 3, through the openings 76 on the side. The filtered oil drips into the lower part of the shell-shaped housing 77 and can be removed from there via a drain device 78. Depending on the condition of the compressed air and the application conditions, other functional units 7 can be used instead of the oil separator 8. For example, a silencer, a silencer or a large-diameter transmission line can be used, through which the air can be transported to a location outside the treatment device 1. Of course, the intersection 6 can be equipped with switches of different designs depending on the functional unit 7 to be connected at any given time.

Claims

PATENT CLAIMS 1. A quick-release valve for pneumatic use with an inlet (12) and an outlet (13) for compressed air, which are in flow communication via a main channel (18), in which a check valve (22) is inserted, which allows the flow of compressed air from the inlet (12) to the outlet (13) and prevents the backflow of compressed air in the opposite direction, which divides the main channel (18) into a first channel section (27) that can be put under pressure on the inlet side and a channel section (28) that is under pressure on the outlet side, characterized in that a bleeder connection (36) is connected to the outlet side channel section (28), in which an automatically operated shut-off valve (38) is connected, which has an open bleeder position (46) that allows the flow of the bleeder connection (36) and the venting channel (36) has a closing member (47) that can be switched between a closing position (45) preventing the passage of air,which is in effective contact with two oppositely directed actuating surfaces (59, 62), one of which, the actuating surface (59) acting in the closing direction (63), is constantly acted upon by the inlet pressure and the actuating surface (62) acting in the opening direction (64) is constantly acted upon by the outlet pressure, and thus the closing member (47) is in a switching position resulting from the pressure difference., 2. A quick-release valve according to claim 1, characterized in that the actuating surface (59) of the shut-off valve (38) effective in the closing direction (63) is formed by a movable wall of a control chamber (57), which is connected to the inlet-side channel section (27) of the main channel (18) via a control channel (58).

3. A quick-release valve according to claim 1 or 2, characterized in that the actuating surfaces (59, 62) are at least partially on a flexible membrane (56) extending between the closure member (47) and the valve housing (5).

4. A quick-release valve according to any one of claims 1-3, characterized in that the actuating surface (59) effective in the closing direction (63) is at least as large or preferably slightly larger than the actuating surface (62) effective in the opposite opening direction (64).

5. A quick-release valve according to any one of claims 1-4, characterized in that the closing member (47) is designed as a pressure-compensated seat member cooperating with the closing seat (44) on the valve housing side.

6. A quick-release valve according to claim 5, characterized in that the bleeder passage (36) is divided by the closing valve (38) into an inlet-side channel section (42) communicating with the outlet-side channel section (28) of the main channel (18) and a bleeder-side channel section, while the closing member (47) in the closed position (45) has a closing surface (65) exposed to the effect of the bleeder pressure prevailing in the outlet-side channel section (43) and an at least substantially identical large compensation surface (66) opposite the closing surface (65), and the compensation surface (66) defines a compensation chamber (70) which communicates with the bleeder passage (36) via a compensation channel (67) preferably penetrating the closing member (47).

7. A quick-release valve according to claim 5 or 6, characterized in that it has a closing spring (74) urging the closing member (47) in the closing direction (63).

8. Quick-release valve according to any one of claims 1-7, characterized in that the closing member (47) is displaceably guided in a guide recess (69) of the valve housing (5) by means of a guide piston (68), and an annular seal (71) is preferably arranged between the guide piston (68) and the guide recess (69).

9. A quick-release valve according to any one of claims 1-8, characterized in that the check valve (22) and the shut-off valve (38) are arranged in a common valve housing (5).

10. Quick-release valve according to claim 9, characterized in that the release port (36) opens out at a cut-out (6) in the valve housing (5) which allows the connection of a functional unit (7), for example an oil separator, a silencer and / or a further air port.

11. A quick-release valve according to any one of claims 1-10, characterized in that it is part of a compressed air treatment device (1).