Pneumatic control block for safely reduced speed

Abstract

Pneumatic control block for safely reduced speed for controlling pneumatic drive components, characterized in that the control block (1) is designed with a first shut-off valve (19) designed as a 7 / 2-way valve, a second shut-off valve (18) designed as a 7 / 2-way valve, two throttles (28, 29), two fixed orifices (16, 17), two check valves (26, 27), two manually actuated vent valves (20, 21), with primary channel A (2), primary channel B (3), first control air channel (5), second control air channel (4), first test air channel (7), second test air channel (6), that the primary channel A (2) and the primary channel B (3) pass through the first shut-off valve (19) and the second shut-off valve (18), and that the housing of the control block is designed in one or more parts.

Description

The invention relates to a pneumatic control block for safely reduced speed for controlling pneumatic drive components, such as double-acting pneumatic cylinders in machines, robotics, and production automation. Pneumatic controls for safely reduced speed are known; for example, in publication FBHM-058 (dated October 11, 2019) of the German Social Accident Insurance (DGUV) Wood and Metal Division for the subject area of ​​machinery, robotics, and production automation, pneumatic controls are proposed which limit the movement of pneumatic drive components to a safely reduced speed for setup, changeover, troubleshooting, and cleaning / maintenance work on machines with the safety device open (switched off). The publication further points out that the design can be achieved with additional control engineering effort using commercially available fluid power components. However, a disadvantage is that the material costs, assembly, and connection of the individual components require a considerable increase in effort. The standardized, safe two-speed valve type VZM5-300-CEW20057, manufactured by pneumatic components company SMC, integrates several fluid power components, thus reducing the additional effort required for assembly and connection of the individual components. However, a disadvantage is that a second valve is required for a second direction of movement. The implementation of pneumatic controls for safely reduced speeds to control pneumatic drive components ultimately has the disadvantage of a considerable increase in effort in the implementation of pneumatic and also electrical controls, especially when a large number of pneumatic drive components are used, which is why machine manufacturers often shy away from the effort and the DGUV publication FBHM-058 refers to the fact that "a reduced speed, e.g. for setup operation, is (still) not implemented in many cases". As part of an overhaul of existing systems, in addition to the need to retrofit pneumatic controls for safely reduced speed, there is often also the need to add pneumatic shut-off valves to ensure the required performance level (e.g. PLd or PLe), for example if directional valves that are not considered safe or digitally controlled valve manifolds are used, or if the performance level needs to be increased. The invention specified in claim 1 is based on the problem of creating a pneumatic control block to complement an external directional control valve, which includes, ready for installation, the fluidic components required for a safely reduced speed of the connected pneumatic drive component, which minimizes the effort required to implement the associated electrical control, and which is preferably also supplemented by one or more shut-off valves to increase the performance level. The aforementioned problems are solved by the features listed in claim 1. The invention achieves that the ready-to-install pneumatic control block includes the fluidic components required for a safely reduced speed of the connected pneumatic drive component, that depending on the design variant, only one control block is required per pneumatic drive component as well as for a second direction of movement, that the performance level is increased by adding shut-off valves, and that, in particular, the effort required to implement the associated electrical control is minimized by using pneumatically actuated valves and pneumatic valve switching position monitoring. Advantageous further developments of the subject matter of claim 1 result from the features of the dependent claims as well as from the description. Exemplary embodiments of the invention are explained with reference to Figures 1-11. Figure 1 shows a pneumatic switching diagram of a pneumatic control block in a maximal embodiment with a first shut-off valve and a second shut-off valve designed as a 7 / 2-way valve, primary channel A and channel B, fixed orifice A and fixed orifice B for limiting the safely reduced speed, and throttle A and throttle B for limiting the maximum speed. Figure 2 shows a pneumatic switching diagram of a pneumatic control block according to Figure 1, but without throttle A and throttle B for limiting the maximum speed. Figure 3 shows a pneumatic switching diagram of a disc-type pneumatic control block similar to Figure 2, and a second control block of the same type, with an inlet plate and an outlet plate. Figure 4 shows a pneumatic switching diagram of a pneumatic control block similar to Figure 1.Fig. 2, but only with fixed orifice B to limit the safely reduced speed in channel B. Fig. 5. Pneumatic switching diagram of a pneumatic control block similar to Fig. 2, but supplemented by unlockable check valve A and unlockable check valve B. Fig. 6. Pneumatic switching diagram of a pneumatic control block similar to Fig. 2, but supplemented by check valve A, check valve B and a vent channel. Fig. 7. Pneumatic switching diagram of a pneumatic control block in a maximum embodiment similar to Fig. 1, but with 4 shut-off valves in the form of a 5 / 2-way valve. Fig. 8. Pneumatic switching diagram of a pneumatic control block similar to Fig. 7, but with only 3 shut-off valves and limitation of the safely reduced speed by means of fixed orifice B only in channel B.Fig. 9 Pneumatic switching diagram of a pneumatic control block with only one primary channel, featuring a 5 / 2-way valve (check valve A1) and a check valve A2, a primary channel A, a fixed orifice plate A to limit the safely reduced speed, and a throttle A to limit the maximum speed. Fig. 10 Pneumatic switching diagram of a pneumatic control block according to Fig. 10, but without throttle A to limit the maximum speed. Fig. 11 Pneumatic switching diagram with a pneumatic control block and a second pneumatic control block, each designed as a disc block, with an inlet plate and an outlet plate. The control blocks are each designed without a second check valve and without throttles to limit the maximum speed. Fig. 1 shows the pneumatic switching diagram of a pneumatic control block 1 in a maximum embodiment with a first shut-off valve 19 and a second shut-off valve 18 designed as a 7 / 2-way valve, primary channel A 2 and channel B 3, fixed orifice A 16 and fixed orifice B 17 for limiting the safely reduced speed, throttle A 28 and throttle B 29 for limiting the maximum speed, check valve A 26 and check valve B 27, first control air channel 5, second control air channel 4, first test air channel 7, second test air channel 6, vent valve A 20 and vent valve B 21. Primary channel A2 and primary channel B3 are used for the reversing control of a pneumatic drive component, such as a double-acting pneumatic cylinder. Channel connections A2 9 and B2 11 are used to connect the external pneumatic drive component. Channel connections A1 8 and B1 10 are used for connecting an external directional control valve. In channel A 2 and channel B 3, the first monostable shut-off valve 19 with spring return is used, which in its rest position 2040 shuts off channel A 2 and channel B 2. If the first shut-off valve 19 is switched to position 2345 by means of pneumatic control air pressure from the first control air channel 5, then channel A 2 and channel B 2 are no longer blocked, and the air flows can then flow freely limited by throttles 28, 29 set to the maximum speed of a connected pneumatic drive component. Parallel to the first shut-off valve 19, bypass channels A 12 and B 13 are used, each of which has a check valve 26, 27 and a fixed orifice 16, 17. The fixed orifices 16, 17 can alternatively be designed as fixed throttles or tamper-proof throttles. If the first shut-off valve 19 is in its rest position 2040 and thus shuts off channel A 2 and channel B 2, it is ensured that the airflow returning from a connected pneumatic drive component flows over one of the two fixed orifices 16, 17, which limit the airflow in such a way that a safely reduced speed of the pneumatic drive component is ensured. The check valves 26, 27 in the bypass channels A 12 and B 13, designed for exhaust air throttling, ensure free airflow to the channel connections A2 9 and B2 11. Furthermore, a first test air channel 7 passes through the first shut-off valve 19, whereby, when an external pressure switch is connected to the first test air channel outlet 25, the switching position of the first shut-off valve 19 can be reliably monitored by an external electrical control, thus advantageously avoiding the use of electrical valve switching position monitoring switches. In addition to the described function of the volume flow which can be switched by means of the first shut-off valve 19, the second shut-off valve 18 is used, which in its rest position 2040 completely blocks channel A 2 and channel B 2, thereby increasing the performance level of the control block 1. If the second shut-off valve 18 is switched to position 2345 by means of pneumatic control air pressure from the second control air channel 4, then channel A 2 and channel B 2 are no longer blocked. In the same way as with the first shut-off valve 19, a second test air channel 6 passes through the second shut-off valve 18, whereby, when an external pressure switch is connected to the second test air channel outlet 23, the switching position of the second shut-off valve 18 can be reliably monitored by an external electrical control. The vent valves 20, 21 are used, if necessary, for the manual venting of air trapped in channel A 2 and channel B 3 before maintenance and repair work. The housing of the pneumatic control block 1 can be made of one or more parts. The valves can be applied from the outside, or alternatively, they can be fully or partially inserted / screwed into the housing. The channel connections 8, 9, 10, 11, 14, 15, 22, 23, 24, 25 can be fitted with threads, or alternatively with push-fit hose quick connectors. This ready-to-install version of the pneumatic control block 1 offers a simplified and error-free installation compared to the cable assembly of individual components. Fig. 2 shows the pneumatic switching diagram of a pneumatic control block 1 according to Fig. 1, but without throttle A and throttle B to limit the maximum speed of a connected pneumatic drive component. This design is particularly suitable for use when external, commercially available throttle check valves are used, which are mounted directly on a connected pneumatic drive component to limit the maximum speed. Fig. 3 shows the pneumatic switching diagram of a disc-type pneumatic control block 1 similar to Fig. 2, a second control block 45 of the same type, with input plate 43 and output plate 44. The housing of each pneumatic control block 1, 45 is designed in disc construction with a left and a parallel right separating plane 42, which allows several control blocks to be advantageously linked together in a modular and space-saving manner in series. The first control air channel 5, the second control air channel 4, the first test air channel 7 and the second test air channel 6 are each passed through the control blocks 1, 45 from the right to the left separating plane 42. The air-carrying channels are sealed at the separation levels 42 by means of seals or sealing plates. The connection of the control blocks 1, 45, the input plate 43 and the output plate 44, which are constructed in disc form, is made by individual screw connections, or alternatively by tie rods. The line connections to be installed for the first control air duct 5, the second control air duct 4, the first test air duct 7 and the second test air duct 6 are advantageously only required at the inlet plate 43 and the outlet plate 44. The drawing shows two control blocks 1, 45 as examples, but it is possible to add further control blocks. Fig. 4 shows the pneumatic switching diagram of a pneumatic control block 1 similar to Fig. 2, but only with fixed orifice B 17 to limit the safely reduced speed in the B-channel 3, and furthermore the first shut-off valve 19 only blocks the B-channel 3, which is why it is sufficient to design it as a 5 / 2-way valve. This design is particularly suitable for use when limiting the safely reduced speed of a connected pneumatic drive component is only required in one direction. Fig. 5 shows the pneumatic switching diagram of a pneumatic control block 1 similar to Fig. 2, but supplemented by unlockable check valve A 30 and unlockable check valve B 31, which are opened in normal operation by control pressure from the check valve control line 32 or the second control air channel 4. When the second shut-off valve 18 closes and the control pressure in the second control air channel 4 is vented, both check valves 30, 31 close and hermetically seal off the air pressure of the connected pneumatic drive component at channel connection A2 9 and channel connection B2 11, thus advantageously keeping it in its current position for a very long time or holding it there. The unlockable check valves 30, 31 are located near the channel connection A2 9 and channel connection B2 11, thereby advantageously compensating for air losses of downstream valves 18, 19 designed in gate valve form. Figure 6 shows the pneumatic circuit diagram of a pneumatic control block 1 similar to Figure 2, but supplemented by a vent check valve A 33, a vent check valve B 34, and a vent channel 35. Under normal operating conditions, air pressure from the vent channel 35 and the second control air channel 4 is present at the vent check valves 33 and 34, respectively, preventing air pressure from escaping from channels A 2 and B 3. When the second shut-off valve 18 closes and the control pressure in the second control air channel 4 is vented, both check valves 33 and 34 open and vent the air pressure present at channel connection A 2 9 and channel connection B 2 11 of the connected pneumatic actuator component, thus ensuring its safe venting. Fig. 7 shows the pneumatic circuit diagram of a pneumatic control block 1 similar to Fig. 1, but with four shut-off valves 36, 37, 38, 39 in a 5 / 2-way valve configuration. The functions are comparable to Fig. 1, however, the shut-off valves are advantageously used in the more common 5 / 2-way valve configuration instead of the 7 / 2-way valve configuration. Fig. 8 shows the pneumatic switching diagram of a pneumatic control block 1 similar to Fig. 7, but with only 3 shut-off valves 36, 38, 39 and limitation of the safely reduced speed by means of a fixed orifice B 17 only in channel B. This design is particularly suitable for use when limiting the safely reduced speed of a connected pneumatic drive component is only required in one direction. Fig. 9 shows the pneumatic circuit diagram of a pneumatic control block 1 with only one primary channel, featuring a 5 / 2-way shut-off valve A1 37 and a shut-off valve A2 36, a primary channel A2, a fixed orifice A16 to limit the safely reduced speed, and a throttle A28 to limit the maximum speed of a connected pneumatic actuator. The addition of a check valve A26, a manual vent valve A20, and their functions are analogous to Fig. 1. This design is particularly suitable for use when the limitation of the safely reduced speed of a connected pneumatic drive component is only required in one direction of movement. Figure 10 shows the pneumatic circuit diagram of a pneumatic control block 1 according to Figure 9, but without throttle A for limiting the maximum speed. This design is particularly suitable when an external, commercially available throttle check valve is used, which is mounted directly on a connected pneumatic drive component to limit the maximum speed. Fig. 11 shows the pneumatic circuit diagram with pneumatic control block 1 and a second pneumatic control block 45, each constructed in disc form, analogous to Fig. 3 with inlet plate 43 and outlet plate 44. However, control blocks 1 and 45 are each designed without a second shut-off valve and without throttles to limit the maximum speed. Pneumatic control block 1 has a function analogous to Fig. 10, and the limitation of the safely reduced speed is thus implemented only for one direction of movement in channel B 3. The second pneumatic control block 45 has a function analogous to Fig. 2, and the limitation of the safely reduced speed is thus implemented for two directions of movement in channel A 2 and channel B 3. The design of pneumatic control block 1 and pneumatic control block 45 are exemplary; alternatively, any switching schemes with, for example, a locking function analogous to Fig. 5 or a venting function of Fig. 6 can be used. The drawing shows two control blocks 1, 45 as examples, but it is possible to add further control blocks. The manual venting valves 20, 21 can alternatively be omitted if manual venting is not required or is implemented externally. As an alternative to the disc-type construction shown, the pneumatic control blocks 1, 45 can also be designed as connection plates with connecting plates on the underside. This simple and cost-effective design of the pneumatic control blocks 1, 45 according to Fig. 11 is suitable if it is only necessary to reliably reduce the speed of a connected pneumatic drive component, and a further increase in performance level by means of an additional shut-off valve is not required. Reference symbol list 1 Pneumatic control block 2 Channel A 3 Channel B 4 Second control air channel 5 First control air channel 6 Second test air channel 7 First test air channel 8 Channel connection A1 9 Channel connection A2 10 Channel connection B1 11 Channel connection B2 12 Bypass channel A 13 Bypass channel B 14 Second control air channel inlet 15 First control air channel inlet 16 Fixed orifice A 17 Fixed orifice B 18 Second shut-off valve 19 First shut-off valve 20 Vent valve A 21 Vent valve B 22 Second test air channel inlet 23 Second test air channel outlet 24 First test air channel inlet 25 First test air channel outlet 26 Check valve A 27 Check valve B 28 Throttle A 29 Throttle B 30 Unlockable check valve A 31 Unlockable check valve B 32 Check valve control line 33 Vent check valve in A 34 Vent check valve in B 35 Vent channel 36 5 / 2-way shut-off valve A2 37 5 / 2-way shut-off valve A1 38 5 / 2-way shut-off valve B2 39 5 / 2-way shut-off valve B1 40 SecondControl air duct outlet 41 First control air duct outlet 42 Separation plane 43 Inlet plate 44 Outlet plate 45 Second control block

Claims

Pneumatic control block for safely reduced speed for controlling pneumatic drive components, characterized in that the control block (1) is designed with a first shut-off valve (19) designed as a 7 / 2-way valve, a second shut-off valve (18) designed as a 7 / 2-way valve, two throttles (28, 29), two fixed orifices (16, 17), two check valves (26, 27), two manually actuated vent valves (20, 21), with primary channel A (2), primary channel B (3), first control air channel (5), second control air channel (4), first test air channel (7), second test air channel (6), that the primary channel A (2) and the primary channel B (3) pass through the first shut-off valve (19) and the second shut-off valve (18), and that the housing of the control block is designed in one or more parts. Pneumatic control block according to claim 1, characterized in that the control block (1) is configured with a 5 / 2-way shut-off valve A1 (37), a 5 / 2-way shut-off valve B1 (39), a 5 / 2-way shut-off valve A2 (36), a 5 / 2-way shut-off valve B2 (38), two throttles (28, 29), two fixed orifices (16, 17), two check valves (26, 27), two manually actuated vent valves (20, 21), primary channel A (2), primary channel B (3), first control air channel (5), second control air channel (4), first test air channel (7), second test air channel (6), that the primary channel A (2) passes through the 5 / 2-way shut-off valve A1 (37) and the 5 / 2-way shut-off valve A2 (36), and that the primary channel B (3) passes through the 5 / 2-way shut-off valve B1 (39) and the 5 / 2-way shut-off valve B2 (38). Pneumatic control block according to one of the preceding claims, characterized in that more than two primary channels (2, 3), and / or more than two control air channels (4, 5), and / or more than two test air channels (6, 7) are used. Pneumatic control block, according to one of the preceding claims, characterized in that instead of the shut-off valves (18, 19) proposed as 7 / 2-way valves, at least partially and in any number 5 / 2-way valves (36, 37, 38, 39) are used. Pneumatic control block, according to one of the preceding claims, characterized in that the shut-off valves (18, 19, 36, 37, 38, 39) designed as directional control valves have more than two switching positions and / or any number of paths. Pneumatic control block, according to one of the preceding claims, characterized in that the shut-off valves (18, 19, 36, 37, 38, 39) designed as directional control valves each have a spring for switching to the home position and a control air connection for an external compressed air signal for switching to a working position. Pneumatic control block, according to one of the preceding claims, characterized in that the throttles (28, 29), fixed orifices (16, 17), check valves (26, 27), vent valves (20, 21), primary channels (2, 3), control air channels (4, 5) and test air channels (6, 7) are each used in any number, or can be omitted. Pneumatic control block, according to one of the preceding claims, characterized in that the fixed orifices (16, 17) are alternatively designed as fixed chokes or tamper-proof chokes. Pneumatic control block, according to one of the preceding claims, characterized in that the housing is designed in disc construction with a left and a right parallel separating plane (42). Pneumatic control block, according to one of the preceding claims, characterized in that the housing is designed in connection plate construction with a separating plane on the underside. Pneumatic control block according to one of the preceding claims, characterized in that the control block (1) is designed with only one primary channel (2) and without a second primary channel (3). Pneumatic control block, according to one of the preceding claims, characterized in that only one primary channel (2 or 3) is equipped with valves, and that a second primary channel (2 or 3) is designed without valves, or with a reduced number of valves. Pneumatic control block, according to one of the preceding claims, characterized in that primary channels (2, 3) are each equipped with only one blocking directional control valve (19, 37), and that the control block (1) is designed without a second control air channel (4), and without a second test air channel (6). Pneumatic control block according to one of the preceding claims, characterized in that the control block (1) has, in addition to a first test air channel inlet (24), a first test air channel outlet (25). Pneumatic control block according to one of the preceding claims, characterized in that the control block (1) has, in addition to a second test air channel inlet (22), a second test air channel outlet (23). Pneumatic control block according to one of the preceding claims, characterized in that the control block (1) has, in addition to a first control air channel inlet (15), a first control air channel outlet (41). Pneumatic control block according to one of the preceding claims, characterized in that the control block (1) has, in addition to a second control air channel inlet (14), a second control air channel outlet (40). Pneumatic control block, according to one of the preceding claims, characterized in that the shut-off valves (18, 19, 36, 37, 38, 39) designed as directional control valves are each traversed by one of the test air channels (6, 7).

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