HYDRAULIC VALVE ASSEMBLY
20240035491 ยท 2024-02-01
Inventors
Cpc classification
F15B2211/30515
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F15B13/015
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F15B11/003
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
Abstract
A hydraulic valve assembly includes a connection section, a first valve section and a pressure line. The first valve section has a first spool piston, a first spool diverter, at least one first consumer port and at least one second consumer port. The first spool diverter can be switched at least into a first spool diverter switching position and a second spool diverter switching position. A shut-off valve is disposed in the pressure line and blocks the pressure line in a blocking position and can be switched from the blocking position into a first release switching position and a second release switching position. The shut-off valve switches into the first release switching position when the first spool diverter is in the first spool diverter switching position and into the second release switching position when the first spool diverter is in the second spool diverter switching position.
Claims
1. A hydraulic valve assembly, comprising: a connection section; a first valve section; and a pressure line, wherein the first valve section can be pressurized by the connection section via the pressure line, wherein the first valve section comprises a first spool piston, a first spool diverter, at least one first consumer port of the first valve section, and at least one second consumer port of the first valve section, wherein a first group of hydraulic consumers can be controlled via the at least one first consumer port of the first valve section, wherein a second group of hydraulic consumers can be controlled via the at least one second consumer port of the first valve section, wherein the first spool diverter can be switched at least into a first spool diverter switching position and a second spool diverter switching position, so that the first group of hydraulic consumers can be controlled via the first spool piston when the first spool diverter is in the first spool diverter switching position, and so that the second group of hydraulic consumers can be controlled via the first spool when the first spool diverter is in the second spool diverter switching position, and wherein a shut-off valve is disposed in the pressure line, and the shut-off valve blocks the pressure line in a blocking position, wherein the shut-off valve can be switched from the blocking position into a first release switching position and a second release switching position, the pressure line being released in the first release switching position and in the second release switching position, wherein the shut-off valve switches to the first release switching position when the first spool diverter is in the first spool diverter switching position, and wherein the shut-off valve switches to the second release switching position when the first spool diverter is in the second spool diverter switching position.
2. The hydraulic valve assembly according to claim 1, wherein the shut-off valve is biased to the blocking position.
3. The hydraulic valve assembly according to claim 1, wherein the first valve section comprises a first reset device, wherein the first reset device biases the first spool diverter into the second spool diverter switching position.
4. The hydraulic valve assembly according to claim 1, wherein the shut-off valve is disposed between the connection section and the first spool piston in the pressure line.
5. The hydraulic valve assembly according to claim 4, wherein the hydraulic valve assembly comprises an intermediate section disposed between the connection section and the first valve section, wherein the shut-off valve is disposed in the intermediate section.
6. The hydraulic valve assembly according to claim 1, wherein the hydraulic valve assembly comprises at least one second valve section which can be pressurized by the connection section via the pressure line, the second valve section having a second spool piston, a second spool diverter, at least one first consumer port of the second valve section and at least one second consumer port of the second valve section, the first group of hydraulic consumers can be controlled via the at least one first consumer port of the second valve section, the second group of hydraulic consumers can be controlled via the at least one second consumer port of the second valve section, the second spool diverter can be switched into a first spool diverter switching position and a second spool diverter switching position, so that the first group of hydraulic consumers can be controlled via the second spool piston when the second spool diverter is in the first spool diverter switching position, and so that the second group of hydraulic consumers can be controlled via the second spool piston when the second spool diverter is in the second spool diverter switching position, wherein the first spool diverter and the second spool diverter switch together and in parallel into the respective first spool diverter switching position or into the respective second spool diverter switching position, wherein the second valve section preferably comprises a second reset device, wherein the second reset device biases the second spool diverter into the second spool diverter switching position.
7. The hydraulic valve assembly according to claim 1, wherein the first valve section comprises at least one third consumer port of the first valve section, a third group of hydraulic consumers can be controlled via the at least one third consumer port of the first valve section, the first spool diverter can be switched into a third spool diverter switching position, so that the third group of hydraulic consumers can be controlled via the first spool piston when the first spool diverter is in the third spool diverter switching position.
8. The hydraulic valve assembly according to claim 7, wherein the second valve section has at least one third consumer port of the second valve section, the third group of hydraulic consumers can be controlled via the at least one third consumer port of the second valve section, the second spool diverter can be switched into a third spool diverter switching position, so that the third group of hydraulic consumers can be controlled via the second spool piston when the second spool diverter is in the third spool diverter switching position, wherein the first spool diverter can be switched together and in parallel with the second spool diverter into the respective third spool diverter switching position.
9. The hydraulic valve assembly according to claim 8, wherein the shut-off valve switches to the first release switching position when the first spool diverter and the second spool diverter are in the third spool diverter switching position.
10. The hydraulic valve assembly according to claim 1, wherein the hydraulic valve assembly comprises a hydraulic pilot control device, the hydraulic pilot control device being configured to apply a pilot pressure the first spool diverter and/or the second spool diverter for common and parallel switching into the first spool diverter switching position and/or the third spool diverter switching position, and wherein pilot pressure can be applied to the shut-off valve via the hydraulic pilot control device for switching from the blocking position into the first release switching position or into the second release switching position.
11. The hydraulic valve assembly according to claim 10, wherein the hydraulic pilot control device has at least one first shut-off valve pilot line for switching the shut-off valve from the blocking position to the first release switching position, wherein a pilot pressure is only applied to the at least one first shut-off valve pilot line when the first spool diverter and the second spool diverter are each in the first spool diverter switching position or when the first spool diverter and the second spool diverter are each in the third spool diverter switching position.
12. The hydraulic valve assembly according to claim 11, wherein the hydraulic pilot device comprises a pilot valve device, a pilot line, a return line, a first pilot branch, and a second pilot branch, wherein a pilot pressure in the first pilot branch switches the first spool diverter and the second spool diverter together into the respective first spool diverter switching position, wherein a pilot pressure in the second pilot branch switches the first spool diverter and the second spool diverter together into the respective third spool diverter switching position, wherein the pilot valve device in a first switching position applies pilot pressure to the first pilot branch and connects the second pilot branch to the return line, and wherein the pilot valve device in a second switching position applies pilot pressure to the second pilot branch and connects the first pilot branch to the return line.
13. The hydraulic valve assembly according to claim 12, wherein the at least one first shut-off valve pilot line can be pressurized with pilot pressure via the first pilot branch and/or via the second pilot branch.
14. The hydraulic valve assembly according to claim 11, wherein the at least one first shut-off valve pilot line can be relieved to the tank via a first relief line.
15. The hydraulic valve assembly according to claim 14, wherein the first relief line opens into the return line of the hydraulic pilot device, a first hydraulic resistor is disposed in the first relief line, and the first hydraulic resistor is a nozzle.
16. The hydraulic valve assembly according to claim 12, wherein the hydraulic valve assembly has a second shut-off valve pilot line for switching the shut-off valve from the blocking position to the second release switching position, wherein pilot pressure is applied to the second shut-off valve pilot line in a third switching position of the pilot valve device.
17. The hydraulic valve assembly according to claim 16, wherein the second shut-off valve pilot line can be relieved to the tank via a second relief line, wherein the second relief line opens into the return line of the hydraulic pilot device, wherein a second hydraulic resistor is disposed in the second relief line, wherein the second hydraulic resistor is a nozzle.
18. A mobile hydraulic system comprising a hydraulic valve assembly according to claim 1, wherein the mobile hydraulic system preferably comprises at least the first group of hydraulic consumers and the second group of hydraulic consumers, wherein the first group of hydraulic consumers is connected in particular to the first consumer port of the first valve section and to the first consumer port of the second valve section, and the second group of hydraulic consumers is connected in particular to the second consumer port of the first valve section and to the second consumer port of the second valve section.
19. A commercial vehicle comprising a mobile hydraulic system according to claim 18.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0031]
[0032]
[0033]
[0034]
[0035]
[0036]
[0037]
[0038]
[0039]
DETAILED DESCRIPTION OF THE DRAWINGS
[0040]
[0041] The first valve section 14 has a first proportional spool piston 22 and a first spool diverter 24. As also shown in particular in
[0042] The second valve section 16 is constructed in the same way as the first valve section 14 and has a second proportional spool piston 26 as well as a second spool diverter 28, which is also configured as an 8/3-spool diverter, cf.
[0043] In order to switch the first spool diverter 24 and the second spool diverter 28 together and in parallel, a hydraulic pilot control device 30 is disposed in the intermediate section 60. The hydraulic pilot control device 30 has a pilot line 34 and a return line 36. The pilot pressure to be applied is tapped directly downstream of the connection section 12 via the pilot line 34. The hydraulic pilot control device 30 further comprises a pilot valve device 32, via which pilot pressure can be applied to the first spool diverter 24 and the second spool diverter 28 in parallel in order to switch the first spool diverter 24 and the second spool diverter 28 together from the respective second switching position S12, S22 into the respective first switching position S11, S21 or into the respective third switching position S13, S23. For this purpose, the pilot valve device 32 can be switched to a first switching position, a second switching position or a third switching position. In the first switching position of the pilot valve device 32, a first pilot branch 38 of the hydraulic pilot device 30 is connected to the pilot line 34, and in the second switching position of the pilot valve device 32, a second pilot branch 40 of the hydraulic pilot device 30 is connected to the pilot line 34. Accordingly, the first pilot branch 38 is connected to the return line 36 in the second switching position of the pilot valve device 32 and the second pilot branch 40 is connected to the return line 36 in the first switching position of the pilot valve device 32.
[0044] To realize these switching positions, the pilot valve device 32 in this embodiment has a first pilot valve 42 and a second pilot valve 44, which connect the first pilot branch 38 and the second pilot branch 40 selectively either to the pilot line 34 or to the return line 36. The first pilot valve 42 and the second pilot valve 44 are each designed as solenoid-operated 3/2-directional valves. The first pilot valve 42 and the second pilot valve 44 are each biased via a corresponding biasing device in such a way that the first pilot branch 38 and the second pilot branch 40 are connected to the return line 36 in the de-energized state of the first pilot valve 42 and the second pilot valve 42 and are thus relieved. To switch the pilot valve device 32 to the first switching position, the first pilot valve 42 is energized so that the pilot line 34 is connected to the first pilot branch 38. The second pilot valve 44 remains de-energized. Accordingly, the second pilot valve 44 is energized to switch the pilot valve device 32 to the second switching position. The first pilot valve 42 is de-energized in the second switching position of the pilot valve device 32.
[0045] Furthermore, the hydraulic valve assembly 10 comprises a shut-off valve 48, which in this embodiment is part of the intermediate section 60. The shut-off valve 48 is disposed in the pressure line 46 between the connection section 12 and the first spool piston 22, and is biased by a corresponding spring device into a blocking position SS such that the pressure line 46 is blocked. In other words, unless the shut-off valve 48 is switched, the first valve section 14 and the second valve section 16 cannot be supplied with pressure. In this embodiment, the shut-off valve 48 is configured as a pilot-controlled 6/3-directional valve.
[0046] In order to switch the shut-off valve 48 to a first release switching position FS1 and to thus release the pressure line 46, the hydraulic pilot control device 30 comprises a first shut-off valve pilot line 50. As shown, the first shut-off valve pilot line 50 is pressurized via the first pilot branch 38 or the second pilot branch 40. For this purpose, the first pilot branch 38 is redirected in the end plate 62 and connected to the first shut-off valve pilot line 50 via the first spool diverter 24 and the second spool diverter 28, provided that the first spool diverter 24 and the second spool diverter 28 are in the first switching position S11, S21, respectively. If one of the two spool diverter valves 24, 28 is not in the first switching position S11, S21, the connection between the first pilot branch 38 and the shut-off valve pilot line 50 is blocked. Accordingly, the second pilot branch 40 is also redirected in the end plate 62 and connected to the first shut-off valve pilot line 50 via the first spool diverter 24 and the second spool diverter 28, provided that the first spool diverter 24 and the second spool diverter 28 are each in the third switching position S13, S23. When either of the spool diverter 24, 28 is not in the third switching position S13, S23, the connection between the second pilot branch 40 and the shut-off valve pilot line 50 is blocked. Thus, the pressure line 46 is released via the shut-off valve 48 only when the first spool diverter 24 and the second spool diverter 28 are in the actually desired switching position.
[0047] For example, if the pilot valve device 32 is switched to the first switching position to switch the first spool diverter 24 to the first switching position S11 and the second spool diverter 28 is also switched to the first switching position S21, the shut-off valve 48 is only switched when both spool diverters 24, 28 also switch to the first switching position S11, S21. If one of the two spool diverter valves 24,28 does not switch properly, the first pilot branch 38 is not connected to the first shut-off valve pilot line 50. The shut-off valve 48 remains in the biased blocking position SS blocking the pressure line 46. Consequently, the first valve section 14 and the second valve section 16 can only be supplied with pressure via the pressure line 46 if the spool diverters 24, 28 are correctly switched.
[0048] In order to also enable pressurization or depressurization of the corresponding second hydraulic connections A21, B21, A24 and B24 of the first valve section 14 under second valve section 16 in the second switching position S12 of the first spool diverter 24 and the second switching position S22 of the second spool diverter 28, the hydraulic valve assembly 10 has a second shut-off valve pilot line 66, via which the shut-off valve 48 can also be pressurized with pilot pressure in order to be switched into a second release switching position FS2 releasing the pressure line 46. For this purpose, the pilot valve device 32 is switched to the third switching position. The second shut-off valve pilot line 66 is connected to the pilot line 34 or the return line 36 via a third pilot valve 64 of the pilot valve device 32. In this exemplary embodiment, the third pilot valve 64 is configured as a solenoid-operated 3/2-directional valve and is biased via a corresponding biasing device in such a way that the second shut-off valve pilot line 66 is connected to the return line 36 in the de-energized state of the third pilot valve 64. If only the third pilot valve 64 is energized and consequently the pilot valve device 32 is switched to the third switching position, the pilot line 34 is connected to the second shut-off valve pilot line 66. As shown in
[0049] To ensure that the shut-off valve 48 is not rendered unswitchable due to a pressure trapped in the first shut-off valve pilot line 50, the first shut-off valve pilot line 50 is relieved to the tank T or return line R via a first relief line 52. As shown in
[0050]
[0051] As shown in
[0052]
[0053] In other words, when the first spool diverter 74 and the second spool diverter 78 are in the second switching position S12, S22, the second consumer ports A21, B21 of the first valve section 14 and the second consumer ports A24, B24 of the second valve section 16 can be pressurized or relieved to the return line R, respectively. The first and third consumer ports A11, B11, A31 and B31 of the first valve section 14 and the first and third consumer ports A14, B14, A34 and B34 of the second valve section 16 are not blocked, but are relieved to the return line R via the first spool diverter 74 and the second spool diverter 78, respectively.
[0054] For this purpose, the first valve section 12 comprises a first main return line 72, via which the consumer ports that cannot be pressurized via the first spool piston 22 are collectively relieved toward the return line R. As shown in particular in
[0055] Accordingly, the second valve section 16 comprises a second main return line 76, via which the consumer ports that cannot be pressurized via the second spool piston 26 are collectively relieved towards the return line R. For this purpose, the second spool diverter 78 has a second collecting channel 84 for each of the three switching positions S21, S22 and S23, which connects the consumer ports not connected to the second spool piston 26 to the second main return line 76 and which are thus relieved to the tank. The second collecting channel 84 is configured in such a way that the consumer ports connected to it are throttled by a second throttle 86 and relieved to the return line R via the second return collecting channel 76.
[0056] The first throttle 82 and the second throttle 86 can be implemented via a hydraulic resistor for each of the connected consumer ports, as shown in
[0057] In
[0058] In addition, the first spool diverter 94 has a first position sensor 92 and the second spool diverter 98 has a second position sensor 96. The first position sensor 92 and the second position sensor 96 transmit a corresponding position signal of the first spool diverter 94 and the second spool diverter 98 to a (not shown) higher-level controller. Thus, it can be determined whether the first spool diverter 94 and the second spool diverter 98 are each in the same switching position, and a faulty control can be reliably excluded.
[0059] The first pilot branch 38 and the second pilot branch 40 are connected to the first shut-off valve pilot line 50 via a selector valve 90. When the pilot valve device 32 is switched to the first switching position to switch the first spool branch 94 and the second spool branch 98 together to the first switching position S11, S21, the first pilot valve 42 is energized. The second pilot valve 44 remains de-energized, so that the second pilot branch 40 is connected to the return line 36. Accordingly, the third pilot valve 64 also remains de-energized, so that the second shut-off valve pilot line 66 is connected to the return line 36. This corresponds to the first switching position of the pilot valve device 32. Consequently, the first pilot branch 38 is connected to the pilot line 34 and the first spool diverter 94 and the second spool diverter 98 are moved together against the first reset device 56 and against the second reset device 58 from the second switching position S12, S22 to the first switching position S11, S12. At the same time, the pilot pressure from the pilot line 34 is signaled via the selector valve 90 and the first shut-off valve pilot line 50 to the shut-off valve 48, which is switched from the blocking position SS to the first release switching position FS1 and releases the pressure line 46. Any residual pressure present in the second shut-off valve pilot line 66 can be relieved directly to the tank T via the return line 36.
[0060] When the first spool diverter 94 and the second spool diverter 98 are to be switched together to the third switching position S13, S23, the second pilot valve 44 is energized and the first pilot valve 42 and the third pilot valve 64 remain de-energized. This corresponds to the second switching position of the pilot valve device 32. Consequently, the second pilot branch 40 is connected to the first shut-off valve pilot line 50 via the selector valve 90. The first pilot branch 38 and the second shut-off valve pilot line 66 are connected to the return line 36, so that any residual pressure is relieved directly to the tank T. The shut-off valve 48 is switched to the first release switching position FS1 and the pressure line 46 is released.
[0061] To switch the first spool diverter 94 and the second spool diverter 98 together to the second switching position S12, S22, the third pilot valve 64 is energized. The first pilot valve 42 and the second pilot valve 44 remain de-energized. This corresponds to the third switching position of the pilot valve device 32. Thus, the first pilot branch 38 and the second pilot branch 40 are connected to the return line 36. Since there is thus no pilot pressure at the first spool valve branch 94 and the second spool valve branch 98, these are switched to the second switching position S12, S22 via the first reset device 56 and the second reset device 58, respectively. At the same time, the pilot pressure from the pilot line 34 is signaled to the shut-off valve 48 via the third pilot valve 64 and the second shut-off valve pilot line 66. The shut-off valve 48 thus switches to the second release switching position FS2 and releases the pressure line 46.
[0062]
[0063] In this embodiment, the pilot valve device 32 is configured such that the pilot pressure for switching the first spool diverter 24 and the second spool diverter 28 to the respective first spool diverter switching position S11, S21 is different from the pilot pressure for switching the first spool diverter 24 and the second spool diverter 28 to the respective third spool diverter switching position S13, S23. Thus, depending on the spool diverter switching position, a different pilot pressure is applied via the first shut-off valve pilot line 50 to the shut-off valve 48 for switching to the first release switching position FS1. In other words, the stroke of the shut-off valve 48 for switching to the first release switching position FS1 depends on whether the first consumer ports A11, B11, A14 and B14 or the third consumer ports A31, B21, A34 and B34 of the respective valve sections 14, 16 are controlled via the first spool piston 24 and the second spool piston 28. The proportional stroke of the shut-off valve 48 can be determined via the displacement transducer 88, so that it is also possible to distinguish the prevailing spool diverter switching position within the first release switching position FS1.
[0064] It is conceivable, for example, that a pressure of 15 bar can be applied via the pilot valve device 32 to the first pilot branch 38 for switching the first spool diverter 24 and the second spool diverter 28 into the respective first spool diverter switching position S11, S21. Accordingly, a pressure of 18 bar, for example, can be applied via the pilot valve device 32 to the second pilot branch 40 for switching the first spool diverter 24 and the second spool diverter 28 into the respective third spool diverter switching position S13, S23. So that the first spool diverter 24 and the second spool diverter 28 switch reliably irrespective of the different pilot pressures, the first reset device 56 and the second reset device 58 are adapted to the correspondingly different pilot pressures. It is possible that the first pilot valve 42 and the second pilot valve 44 are also configured as proportional valves so as to apply the different pilot pressures to the respective pilot branch 38, 40.
[0065] In both cases, the shut-off valve 48 switches to the first release switching position FS1, but with a different stroke in each case, which is detected via the displacement transducer 88. The shut-off valve 48 is preferably configured in such a way that the quantity flowing via the shut-off valve 48 is independent of the stroke in the first release switching position FS1, but in both cases corresponds at least to the maximum quantity required to control the correspondingly connected hydraulic consumers.
[0066] In
[0067] To control the first group G1.1, the spool diverters of the five valve sections are switched together to the first switching position S11, S21, . . . . The other groups G2 and G1.2 are blocked. Accordingly, the spool diverters of the five valve sections are switched together into the second switching position S12, S22, . . . in order to control the second group G2 of hydraulic consumers. The first group G1.1 and the third group G1.2 are blocked. In order to control the third group G1.2 at hydraulic consumers, the spool diverters of the five valve sections are switched together to the third switching position S13, S23, . . . . The first group G1.1 and the second group G2 are blocked. Based on the resulting position of the shut-off valve 48 in the first release switching position FS1 or in the second release switching position FS2, it can be reliably derived whether the supports (in the first group G1.1 and the third group G1.2) or the mast (in the second group G2) are currently being controlled.
[0068] According to the present invention, of course, any number of valve sections may be used, depending on the requirements of the mobile hydraulic system 100. Also, the embodiments may be combined with each other. For example, it is conceivable for a hydraulic valve assembly 10 to have a first spool piston 24 in the first valve section 14 in accordance with the first embodiment and to have a spool piston 74 in the second valve section 16 in accordance with the second embodiment. Finally, it should also be pointed out that the terms used herein, such as first, second or third, do not specify a specific order, but serve exclusively to separate and distinguish elements and features.
LIST OF REFERENCE SIGNS
[0069] 10 hydraulic valve assembly [0070] 12 connection section [0071] 14 first valve section [0072] 16 second valve section [0073] 18 third valve section [0074] 20 fourth valve section [0075] 22 first spool piston [0076] 24 first spool diverter [0077] 26 second spool piston [0078] 28 second spool diverter [0079] 30 hydraulic pilot control device [0080] 32 pilot valve device [0081] 34 pilot line [0082] 36 return line [0083] 38 first pilot branch [0084] 40 second pilot branch [0085] 42 first pilot valve [0086] 44 second pilot valve [0087] 46 pressure line [0088] 48 shut-off valve [0089] 50 first shut-off valve pilot line [0090] 52 first relief line [0091] 54 first hydraulic resistor/nozzle [0092] 56 first reset device [0093] 58 second reset device [0094] 60 intermediate section [0095] 62 end plate [0096] 64 third pilot valve [0097] 66 second shut-off valve pilot line [0098] 68 second relief line [0099] 70 second hydraulic resistor/nozzle [0100] 72 first main return line [0101] 74 first spool diverter [0102] 76 second main return line [0103] 78 second spool diverter [0104] 80 collecting channel of first spool diverter [0105] 82 first throttle of the first spool diverter [0106] 84 collecting channel of second spool diverter [0107] 86 second throttle of second spool diverter [0108] 88 displacement transducer [0109] 90 selector valve [0110] 92 first position sensor [0111] 94 first spool diverter [0112] 96 second position sensor [0113] 98 second spool diverter [0114] 100 mobile hydraulic system [0115] 200 commercial vehicle [0116] A11 (first) consumer port of the first valve section [0117] A14 (first) consumer port of the second valve section [0118] A21 (second) consumer port of the first valve section [0119] A24 (second) consumer port of the second valve section [0120] A31 (third) consumer port of the first valve section [0121] A34 (third) consumer port of the second valve section [0122] B11 (first) consumer port of the first valve section [0123] B14 (first) consumer port of the second valve section [0124] B21 (second) consumer port of the first valve section [0125] B24 (second) consumer port of the second valve section [0126] B31 (third) consumer port of the first valve section [0127] B34 (third) consumer port of the second valve section [0128] FS1 first release switching position [0129] FS2 second release switching position [0130] G1.1 first group of hydraulic consumers [0131] G2 second group of hydraulic consumers [0132] G1.2 third group of hydraulic consumers [0133] P pressure connection/pump [0134] R return line [0135] T tank [0136] S11 first spool diverter switching position of first spool diverter [0137] S12 second spool diverter switching position of first spool diverter [0138] S13 third spool diverter switching position of first spool diverter [0139] S21 first spool diverter switching position of second spool diverter [0140] S22 second spool diverter switching position of second spool diverter [0141] S23 third spool diverter switching position of second spool diverter [0142] SS blocking position