Retractable control device and construction machinery

Abstract

The present invention discloses a telescopic control device and a construction machinery. The telescopic control device includes a main control circuit, a brake control circuit and a telescopic motor. A telescopic control valve and a hydraulic lock valve are provided on the main control circuit. A brake valve, a hydraulic stroke switch valve and a brake are provided on the brake control circuit. The brake valve and the hydraulic stroke switch valve are used to control the connection or disconnection of the brake pressure oil circuit and the brake, and the brake valve and the hydraulic stroke switch valve are also used to control the commutation of the hydraulic lock valve, so as to control the disconnection of the main control pressure oil circuit and the telescopic motor when the brake pressure oil circuit and the brake are disconnected. In the telescopic control device and the construction machinery of the present invention, the hydraulic stroke switch valve switches positions to lock the telescopic motor by the brake, and at the same time, the hydraulic stroke switch valve is linked with the hydraulic lock valve on the main control pressure oil circuit to achieve double braking, fundamentally improving the reliability of the telescopic mechanism lock.

Description

Technical Field

[0001] The present invention relates to the technical field of construction machinery, and particularly to a telescopic control device and a construction machinery. Background Art

[0002] In a ladder truck, there are two common ways to extend and retract the ladder frame. One is for a ladder truck with a relatively small telescopic length, where a hydraulic cylinder drives a wire rope pulley set to achieve the extension and retraction of the ladder frame. The other is for a ladder truck with a relatively large telescopic length, where a winch mechanism drives a wire rope pulley set to achieve the extension and retraction of the ladder frame.

[0003] When a winch mechanism is used to drive the extension and retraction of the ladder frame, safety protection measures must be taken when the ladder frame extends to the extreme position to prevent the ladder frame from extending too much or even slipping out. There are two common methods for this prevention: One method is to send an electrical signal through an electrical proximity switch, and the solenoid valve in the hydraulic system is controlled by the electrical system to cut off the main pressure oil circuit. The other method is to use mechanical limit to force the ladder frame to stop. As Figure 1 shown, the second ladder frame 13 extends relative to the first ladder frame 12 in the direction of the arrow. A first stop block 14 and a proximity switch 16 are provided on the first ladder frame 12, and a second stop block 15 is provided on the second ladder frame 13. When the second ladder frame 13 extends to the end position, in order to prevent the ladder frame from extending too much or slipping out, the ladder frame must be locked. One method is to use an electrical proximity switch 16 to control the solenoid valve in the hydraulic system by sending an electrical signal to lock the ladder frame. As Figure 1 shown, there is an induction distance a (for example, the vertical distance between the proximity switch 16 and the second stop block 15) between the proximity switch 16 and the induction block (such as the second stop block 15) on the second ladder frame 13. This induction distance a can be adjusted, but it must be within a suitable range to effectively sense and generate an electrical signal to control the hydraulic valve, cut off the pressure oil, and thus stop the winch motor from rotating. However, in actual use, the induction distance a may change, which may cause the proximity switch 16 to be unable to effectively sense and generate an electrical signal; or, the sensing surface of the proximity switch 16 may be contaminated, and rainwater, etc. may cause damage to the proximity switch, resulting in the failure of the electrical control of the ladder frame lock. In addition, when the ladder frame and the wire rope are adjusted, or the hydraulic valve is manually operated without using the electrical system, the electrical control method for locking the ladder frame also fails. Another method is to use a mechanical method to lock the ladder frame. The first stop block 14 is blocked by the second stop block 15 to forcibly lock the ladder frame, and the second stop block 15 will generate a large blocking force on the first stop block 14. However, when the ladder frame and the wire rope are adjusted, or manually operated, it may cause an excessive clamping force between the second stop block 15 and the first stop block 14, which may lead to deformation of the ladder frame structure.

[0004] Therefore, there are certain drawbacks in locking the ladder frame mechanically or electrically. When using electrical control, the induction of the proximity switch may fail for various reasons, and the accuracy and reliability of the ladder frame locking cannot be guaranteed; when adjusting the ladder frame and the wire rope, the ladder frame locking protection of the electrical control is generally cancelled; when manually operating the hydraulic system emergently or forcibly, the ladder frame locking of the electrical control has already failed; when the fire truck conducts hydraulic system debugging, the electrical system is usually not used, and the ladder frame locking of the electrical control also fails. When using mechanical locking, the locking structure has to bear a large acting force, which will cause certain damage to the locking structure in the long run, resulting in poor locking reliability. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a telescopic control device and a construction machinery that can lock the telescopic mechanism reliably and conveniently.

[0006] The present invention provides a telescopic control device, including a main control circuit, a braking control circuit and a telescopic motor. The main control circuit includes a main control pressure oil circuit and a main control return oil circuit. A telescopic control valve and a hydraulic locking valve are provided on the main control circuit. The telescopic control valve is used to switch and control the forward rotation, reverse rotation or stop of the telescopic motor. The braking control circuit includes a braking pressure oil circuit and a braking return oil circuit. A braking valve, a hydraulic travel switch valve and a brake are provided on the braking control circuit. The braking pressure oil circuit is used to supply pressure oil to the brake. The braking valve and the hydraulic travel switch valve are used to control the connection or disconnection of the braking pressure oil circuit and the brake, and are used to control the connection or disconnection of the braking return oil circuit and the brake. The braking valve and the hydraulic travel switch valve are also used to control the commutation of the hydraulic locking valve, so as to control the disconnection of the main control pressure oil circuit of the main control circuit and the telescopic motor when the braking pressure oil circuit and the brake are disconnected.

[0007] In an embodiment, the telescopic control valve further includes a pressure oil port, a return oil port, a first working oil port and a second working oil port. The telescopic motor includes a motor first oil port and a motor second oil port. The main control circuit further includes a first working oil circuit and a second working oil circuit. The pressure oil port is connected to the main control pressure oil circuit, the return oil port is connected to the main control return oil circuit, the first working oil circuit is connected between the first working oil port and the motor first oil port, and the second working oil circuit is connected between the second working oil port and the motor second oil port; the hydraulic locking valve is provided on the first working oil circuit, and connects the first working oil circuit when the hydraulic travel switch valve connects the brake and the braking pressure oil circuit, and disconnects the first working oil circuit when the hydraulic travel switch valve disconnects the brake and the braking pressure oil circuit.

[0008] In one embodiment, the hydraulic lock valve includes a first position and a second position. When the hydraulic lock valve is in the first position, the first working oil circuit is connected. When the hydraulic lock valve is in the second position, the first working oil circuit is disconnected, and the hydraulic lock valve connects the first oil port of the motor to the second working oil circuit. The hydraulic lock valve includes a first control oil port and a second control oil port. The first control oil port is connected to the hydraulic stroke switch valve and switches the position of the hydraulic lock valve according to the position of the hydraulic stroke switch valve so that the hydraulic lock valve is in the second position. The second control oil port is connected to the second working oil circuit and switches the position of the hydraulic lock valve when the second working oil circuit is connected to the main control pressure oil circuit so that the hydraulic lock valve is in the first position.

[0009] In one embodiment, the hydraulic stroke switch valve includes a first hydraulic stroke switch valve and a second hydraulic stroke switch valve. The brake valve is connected between the first hydraulic stroke switch valve and the brake pressure oil circuit. The first hydraulic stroke switch valve is connected to the brake. The brake valve is used to connect or disconnect the first hydraulic stroke switch valve from the brake pressure oil circuit. The first hydraulic stroke switch valve is used to connect or disconnect the brake valve from the brake. The second hydraulic stroke switch valve is connected to the brake pressure oil circuit. The second hydraulic stroke switch valve is also connected to the first control oil port of the hydraulic lock valve. The second hydraulic stroke switch valve is used to connect or disconnect the brake pressure oil circuit from the first control oil port of the hydraulic lock valve to control the position switching of the hydraulic lock valve.

[0010] In one embodiment, a shuttle valve is provided between the first working oil circuit and the second working oil circuit. The control oil port of the brake valve is connected to the oil outlet of the shuttle valve to control the position switching of the brake valve. When any one of the first working oil circuit and the second working oil circuit is high-pressure oil, the brake valve connects the first hydraulic stroke switch valve to the brake pressure oil circuit. When both the first working oil circuit and the second working oil circuit are low-pressure oil, the brake valve disconnects the first hydraulic stroke switch valve from the brake pressure oil circuit.

[0011] In one embodiment, a hydraulic valve is further provided on the brake control loop. One end of the hydraulic valve is connected to the brake, and the other end is respectively connected to the brake valve and the brake oil return circuit. The hydraulic valve is used to connect or disconnect the brake from the brake pressure oil circuit. The control oil port of the hydraulic valve is connected to the second working oil circuit, and switches to the position of connecting the brake to the brake pressure oil circuit when the second working oil circuit is connected to the main control pressure oil circuit. The hydraulic valve is also used to connect or disconnect the brake from the brake oil return circuit, and connects the brake to the brake oil return circuit when the second working oil circuit is disconnected from the main control pressure oil circuit and the hydraulic stroke switch valve disconnects the brake from the brake pressure oil circuit.

[0012] In one embodiment, the brake valve includes a first brake oil port, a second brake oil port, and a third brake oil port. The third brake oil port is connected to the first brake oil port or the second brake oil port when the brake valve switches positions. The first brake oil port is connected to the brake pressure oil circuit, and the second brake oil port is connected to the brake oil return circuit. The brake valve includes a first position and a second position. When the brake valve is in the first position, it connects the first brake oil port to the third brake oil port, and when in the second position, it connects the second brake oil port to the third brake oil port. The hydraulic valve includes a first hydraulic oil port, a second hydraulic oil port, a third hydraulic oil port, and a fourth hydraulic oil port. The first hydraulic oil port is connected to the third brake oil port of the brake valve, the second hydraulic oil port is connected to the brake oil return circuit, the third hydraulic oil port is connected to the brake, and the fourth hydraulic oil port is connected to the second hydraulic stroke switch valve. When the hydraulic valve switches positions, it connects the brake to the brake valve, or connects the second hydraulic stroke switch valve to the brake oil return circuit. The second hydraulic stroke switch valve includes a first switch oil port, a second switch oil port, and a third switch oil port. The first switch oil port is connected to the brake pressure oil circuit, the second switch oil port is connected to the fourth hydraulic oil port of the hydraulic valve, and the third switch oil port is connected to the first control oil port of the hydraulic lock valve. When the second hydraulic stroke switch valve switches positions, it connects the first switch oil port to the first control oil port of the hydraulic lock valve, or connects the second switch oil port to the first control oil port of the hydraulic lock valve. The first hydraulic stroke switch valve includes a fourth switch oil port, a fifth switch oil port, and a sixth switch oil port. The fourth switch oil port is connected to the third brake oil port of the brake valve, the fifth switch oil port is connected to the fourth hydraulic oil port of the hydraulic valve, and the sixth switch oil port is connected to the brake. When the first hydraulic stroke switch valve switches positions, it connects the fourth switch oil port to the sixth switch oil port, or connects the fifth switch oil port to the sixth switch oil port.

[0013] In one embodiment, a pressure reducing valve is further provided on the brake control circuit. The oil inlet of the pressure reducing valve is connected to the brake pressure oil circuit. The oil outlet of the pressure reducing valve is connected to the first brake oil port of the brake valve. The control oil port of the pressure reducing valve is connected to the first brake oil port of the brake valve. The outlet pressure of the pressure reducing valve is greater than the spring pressure of the hydraulic lock valve. An overflow valve is further provided on the brake control circuit. One working oil port of the overflow valve is connected to the second switch oil port of the second hydraulic stroke switch valve. The other working oil port is connected to the second hydraulic oil port of the hydraulic valve and the brake oil return circuit. The control oil port of the overflow valve is connected to the second switch oil port of the second hydraulic stroke switch valve. The main control circuit further includes a two-way balance valve. The two-way balance valve includes a first balance valve provided in the first working oil circuit and a second balance valve provided in the second working oil circuit. The pilot oil circuit of the sequence valve in the first balance valve is connected to the second working oil circuit. The pilot oil circuit of the sequence valve in the second balance valve is connected to the first working oil circuit.

[0014] In one embodiment, the telescopic control device may further include a swing control valve for controlling the swing of the telescopic mechanism. The oil inlet and the oil return port of the swing control valve are respectively connected to the main control pressure oil circuit and the main control oil return circuit; and / or, the telescopic control device may further include a luffing control valve for controlling the luffing of the telescopic mechanism. The oil inlet and the oil return port of the luffing control valve are respectively connected to the main control pressure oil circuit and the main control oil return circuit.

[0015] The present invention further provides a construction machine, including a telescopic mechanism and the above-mentioned telescopic control device. The telescopic control device at least controls the telescoping of the telescopic mechanism.

[0016] In the telescopic control device and the construction machine provided by the embodiments of the present invention, when the telescopic mechanism extends to the limit position, the brake oil chamber of the brake can be depressurized and returned to the hydraulic oil tank by operating the hydraulic stroke switch valve, so that the brake locks the telescopic motor and makes it unable to operate, which fundamentally improves the reliability of the locking of the telescopic mechanism. In addition, the hydraulic stroke switch valve is also linked with the hydraulic lock valve on the main control pressure oil circuit. While the brake is locked, the position of the hydraulic lock valve is controlled to prevent the main control pressure oil circuit from supplying oil to the telescopic motor, realizing double braking and further improving the reliability of the locking of the telescopic mechanism. Description of the Drawings

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0018] Figure 1 It is a partial structural schematic diagram of a telescopic ladder in a telescopic ladder fire truck.

[0019] Figure 2 It is a hydraulic schematic diagram of the telescopic control device according to an embodiment of the present invention.

[0020] Figure 3 It is Figure 2 The hydraulic schematic diagram of the shown telescopic control device when the telescopic mechanism extends.

[0021] Figure 4 It is Figure 2 The hydraulic schematic diagram of the shown telescopic control device when the telescopic mechanism extends in place.

[0022] Figure 5 It is Figure 2 The hydraulic schematic diagram of the shown telescopic control device when the telescopic mechanism extends and the ladder rotates or changes amplitude.

[0023] Figure 6 It is Figure 2 The hydraulic schematic diagram of the shown telescopic control device when the telescopic mechanism just retracts.

[0024] Figure 7 It is Figure 2 The hydraulic schematic diagram of the shown telescopic control device during the retraction process of the telescopic mechanism. Specific embodiments

[0025] The following will combine the drawings to describe in detail specific embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the description of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope protected by the present invention.

[0026] In the description of the present invention, unless otherwise clearly defined and limited, terms such as "set", "installed", "connected", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific situations.

[0027] The orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the inventive product is customarily placed during use. It is only for the convenience of description and to simplify the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present invention.

[0028] Terms such as "first", "second", "third", etc. are only used to distinguish elements with similar attributes, rather than indicating or implying relative importance or a specific order.

[0029] The term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion. In addition to the elements listed, it may also include other elements not specifically listed.

[0030] Please refer Figure 2 , The telescopic control device of an embodiment of the present invention includes a main control circuit, a brake control circuit and a telescopic motor 21. The main control circuit includes a main control pressure oil circuit 30 and a main control oil return circuit 31. A telescopic control valve 33 and a hydraulic lock valve 35 are provided on the main control circuit. The telescopic control valve 33 is used to switch and control the forward rotation, reverse rotation or stop operation of the telescopic motor 21. The brake control circuit includes a brake pressure oil circuit 50 and a brake oil return circuit 51. A brake valve 52, a hydraulic travel switch valve 53 and a brake 55 are provided on the brake control circuit. The brake pressure oil circuit is used to supply pressure oil to the brake 55. The brake valve 52 and the hydraulic travel switch valve 53 are used to control the connection or disconnection of the brake pressure oil circuit 50 and the brake 55, and are used to control the connection or disconnection of the brake oil return circuit 51 and the brake 55. The brake valve 52 and the hydraulic travel switch valve 53 are used to control the commutation of the hydraulic lock valve 35 to control the disconnection of the main control pressure oil circuit of the main control circuit and the telescopic motor 21 when the brake pressure oil circuit is disconnected from the brake 55. Specifically, the main control pressure oil circuit 30 and the brake pressure oil circuit 50 can be connected and supplied by the same hydraulic pump, or can be independent of each other and supplied by different hydraulic pumps. It can be understood that the telescopic control device further includes a fuel tank 10. The fuel tank 10 supplies oil to the hydraulic pump, and the oil returned from the main control circuit and the brake control circuit flows back to the fuel tank 10. When the hydraulic travel switch valve reaches a predetermined position and touches its handle, the hydraulic travel switch valve will automatically switch to a state opposite to the initial state, so as to change the oil flow direction of the hydraulic system or terminate the liquid flow. Compared with an electrical travel switch, the hydraulic travel switch valve has higher reliability.

[0031] In the telescopic control device of this embodiment, when the telescopic mechanism extends to the limit position, the hydraulic stroke switch valve can be manipulated to relieve the pressure of the brake oil chamber of the brake back to the hydraulic oil tank, so that the brake locks the telescopic motor and makes it inoperable, which fundamentally improves the reliability of the locking of the telescopic mechanism. In addition, the hydraulic stroke switch valve is also linked with the hydraulic lock valve on the main control pressure oil circuit. When the brake locks, the hydraulic lock valve is controlled to switch positions, so that the main control pressure oil circuit cannot supply oil to the telescopic motor, realizing double braking and further improving the reliability of the locking of the telescopic mechanism.

[0032] In this embodiment, the telescopic control valve 33 further includes a pressure oil port P1, a return oil port T1, a first working oil port A1, and a second working oil port B1. The telescopic motor 21 includes a motor first oil port A2 and a motor second oil port B2. The main control circuit further includes a first working oil circuit 36 and a second working oil circuit 37. The pressure oil port P1 is connected to the main control pressure oil circuit 30, and the return oil port T1 is connected to the main control return oil circuit 31. The first working oil circuit 36 is connected between the first working oil port A1 and the motor first oil port A2, and the second working oil circuit 37 is connected between the second working oil port B1 and the motor second oil port B2. The hydraulic lock valve 35 is arranged on the first working oil circuit 36 and connects the first working oil circuit 36 when the hydraulic stroke switch valve 53 connects the brake 55 and the brake pressure oil circuit 50, and disconnects the first working oil circuit 36 when the hydraulic stroke switch valve 53 disconnects the brake 55 and the brake pressure oil circuit 50.

[0033] In this embodiment, the telescopic control valve 33 has two first positions and second positions. When the telescopic control valve 33 is in the first position, the main control pressure oil circuit 30 is connected to the first working oil circuit 36, and the main control return oil circuit 31 is connected to the second working oil circuit 37. At this time, it can be designed that the telescopic motor 21 rotates forward and the ladder extends; when the telescopic control valve 33 is in the second position, the main control pressure oil circuit 30 is connected to the second working oil circuit 37, and the main control return oil circuit 31 is connected to the first working oil circuit 36. At this time, it can be designed that the telescopic motor 21 rotates reversely and the ladder retracts. It can be understood that it can also be designed that when the telescopic control valve 33 is in the first position, the telescopic motor 21 rotates reversely and the ladder retracts, and when the telescopic control valve 33 is in the second position, the telescopic motor 21 rotates forward and the ladder extends.

[0034] Specifically, the telescopic control valve 33 further includes a third position (generally the middle position). When the telescopic control valve 33 is in the third position, both the first working oil circuit 36 and the second working oil circuit 37 are connected to the main control return oil circuit 31 and are disconnected from the main control pressure oil circuit 30.

[0035] In this embodiment, the hydraulic lock valve 35 includes a first position and a second position. When the hydraulic lock valve 35 is in the first position, the first working oil circuit 36 is connected. When the hydraulic lock valve 35 is in the second position, the first working oil circuit 36 is disconnected, and the hydraulic lock valve 35 connects the first oil port A2 of the motor to the second working oil circuit 37. The hydraulic lock valve 35 includes a first control oil port and a second control oil port. The first control oil port is connected to the hydraulic travel switch valve 53 and switches the position of the hydraulic lock valve 35 according to the position of the hydraulic travel switch valve 53 so that the hydraulic lock valve 35 is in the second position. The second control oil port is connected to the second working oil circuit 37 and switches the position of the hydraulic lock valve 35 when the second working oil circuit 37 is connected to the main control pressure oil circuit 30 so that the hydraulic lock valve 35 is in the first position.

[0036] Specifically, when the hydraulic travel switch valve 53 reaches the limit position and switches its position, thus connecting the first control oil port to the braking pressure oil circuit 50, it pushes the hydraulic lock valve 35 to the second position, disconnecting the first working oil circuit 36 and prohibiting the first working oil circuit 36 from supplying oil to the telescopic motor 21. Therefore, the telescopic motor 21 will not rotate. When the second working oil circuit 37 is connected to the main control pressure oil circuit 50, the high-pressure oil pushes the hydraulic lock valve 35 to switch from the second position to the first position.

[0037] In this embodiment, the hydraulic travel switch valve 53 includes a first hydraulic travel switch valve 532 and a second hydraulic travel switch valve 534. The brake valve 52 is connected between the first hydraulic travel switch valve 532 and the braking pressure oil circuit 50. The first hydraulic travel switch valve 532 is connected to the brake 55. The brake valve 52 is used to connect or disconnect the first hydraulic travel switch valve 532 from the braking pressure oil circuit 50. The first hydraulic travel switch valve 532 is used to connect or disconnect the brake valve 52 from the brake 55. The second hydraulic travel switch valve 534 is connected to the braking pressure oil circuit 50, and the second hydraulic travel switch valve 534 is also connected to the first control oil port of the hydraulic lock valve 35. The second hydraulic travel switch valve 534 is used to connect or disconnect the braking pressure oil circuit 50 from the first control oil port of the hydraulic lock valve 35 to control the position switching of the hydraulic lock valve 35. In this way, when the ladder frame extends to the limit position, the first hydraulic travel switch valve 532 and the second hydraulic travel switch valve 534 automatically switch their positions, thus disconnecting the braking pressure oil circuit 50 from the brake 55, braking the brake 55, and connecting the braking pressure oil circuit 50 to the first control oil port of the hydraulic lock valve 35, causing the hydraulic lock valve 35 to switch its position, preventing the main control pressure oil circuit 30 from supplying oil to the telescopic motor 21 and thus preventing the ladder frame from continuing to extend, achieving double locking.

[0038] Specifically, a shuttle valve 39 is provided between the first working oil circuit 36 and the second working oil circuit 37. The control oil port of the brake valve 52 is connected to the oil outlet of the shuttle valve 39 to control the switching position of the brake valve 52. When either the first working oil circuit 36 or the second working oil circuit 37 is high-pressure oil, the brake valve 52 is in the right position, and the brake valve 52 connects the first hydraulic travel switch valve 532 to the brake pressure oil circuit 50. When both the first working oil circuit 36 and the second working oil circuit 37 are low-pressure oil, the brake valve 52 disconnects the first hydraulic travel switch valve 532 from the brake pressure oil circuit 50. Specifically, one end of the shuttle valve 39 is connected between the hydraulic lock valve 35 and the telescopic motor 21. Thus, when the hydraulic lock valve 35 disconnects the first working oil circuit 36, even if the first working oil circuit 36 is connected to the main control pressure oil circuit 30, the first working oil circuit 36 is still low-pressure oil.

[0039] Specifically, a hydraulic valve 57 is further provided on the brake control loop. One end of the hydraulic valve 57 is connected to the brake 55, and the other end is respectively connected to the brake valve 52 and the brake oil return circuit 51. The control oil port of the hydraulic valve 57 is connected to the second working oil circuit 37. The hydraulic valve 57 is used to connect or disconnect the brake 55 from the brake pressure oil circuit 50, and switches to the position of connecting the brake 55 to the brake pressure oil circuit 50 when the second working oil circuit 37 is connected to the main control pressure oil circuit 30 to supply pressure oil to the brake 55. The hydraulic valve 57 is also used to connect or disconnect the brake 55 from the brake oil return circuit 51, and connects the brake 55 to the brake oil return circuit 51 when the second working oil circuit 37 is disconnected from the main control pressure oil circuit 30 and the hydraulic travel switch valve 53 disconnects the brake 55 from the brake pressure oil circuit 50, so that the brake 55 drains oil to release the brake. The control oil port of the hydraulic valve 57 is connected to the second working oil circuit 37. The spring opening pressure of the hydraulic valve 57 can be 3 - 5 Mpa.

[0040] Specifically, the brake valve 52 includes a first brake oil port 522, a second brake oil port 524, and a third brake oil port 526. The third brake oil port 526 communicates with the first brake oil port 522 or the second brake oil port 524 when the brake valve 52 switches positions. The first brake oil port 522 is connected to the brake pressure oil circuit 50, and the second brake oil port 524 is connected to the brake oil return circuit 51. Specifically, the brake valve 52 includes a first position (right position) and a second position (left position). When the brake valve 52 is in the first position, it communicates the first brake oil port 522 with the third brake oil port 526, and when in the second position, it communicates the second brake oil port 524 with the third brake oil port 526. The hydraulic valve 57 includes a first hydraulic oil port 571, a second hydraulic oil port 572, a third hydraulic oil port 573, and a fourth hydraulic oil port 574. The first hydraulic oil port 571 is connected to the third brake oil port 526 of the brake valve 52, the second hydraulic oil port 572 is connected to the brake oil return circuit 51, the third hydraulic oil port 573 is connected to the brake 55, and the fourth hydraulic oil port 574 is connected to the second hydraulic stroke switch valve 534. The hydraulic valve 57 communicates the brake 55 with the brake valve 52 or the second hydraulic stroke switch valve 534 with the brake oil return circuit 51 when switching positions. The second hydraulic stroke switch valve 534 includes a first switch oil port 5341, a second switch oil port 5342, and a third switch oil port 5343. The first switch oil port 5341 is connected to the brake pressure oil circuit 50, the second switch oil port 5342 is connected to the fourth hydraulic oil port 574 of the hydraulic valve 57, and the third switch oil port 5343 is connected to the first control oil port of the hydraulic lock valve 35. The second hydraulic stroke switch valve 534 communicates the first switch oil port 5341 with the first control oil port of the hydraulic lock valve 35 (at this time, the brake pressure oil circuit 50 is communicated with the first control oil port of the hydraulic lock valve 35, causing the spool of the hydraulic lock valve 35 to move and switch positions) or the second switch oil port 5342 with the first control oil port of the hydraulic lock valve 35 when switching positions. The first hydraulic stroke switch valve 532 includes a fourth switch oil port 5322, a fifth switch oil port 5323, and a sixth switch oil port 5324. The fourth switch oil port 5322 is connected to the third brake oil port 526 of the brake valve 52, the fifth switch oil port 5323 is connected to the fourth hydraulic oil port 574 of the hydraulic valve 57, and the sixth switch oil port 5324 is connected to the brake 55. The first hydraulic stroke switch valve 532 communicates the fourth switch oil port 5322 with the sixth switch oil port 5324 or the fifth switch oil port 5323 with the sixth switch oil port 5324 when switching positions, thereby realizing braking of the brake 55 or bleeding the brake 55. The spring opening pressure of the brake valve 52 can be 3 - 5 Mpa.

[0041] In this embodiment, a pressure reducing valve 59 is further provided on the brake control circuit. The oil inlet of the pressure reducing valve 59 is connected to the brake pressure oil circuit 50, the oil outlet of the pressure reducing valve 59 is connected to the first brake oil port 522 of the brake valve 52, and the control oil port of the pressure reducing valve 59 is connected to the first brake oil port 522 of the brake valve 52. Specifically, the outlet pressure of the pressure reducing valve 59 is greater than the spring pressure of the hydraulic lock valve 35. More specifically, the outlet pressure of the pressure reducing valve 59 can be 5-7 Mpa, and the spring pressure of the hydraulic lock valve 35 can be 3-5 Mpa.

[0042] In this embodiment, a relief valve 61 is further provided on the brake control circuit. One working oil port of the relief valve 61 is connected to the second switch oil port 5342 of the second hydraulic stroke switch valve 534, the other working oil port is connected to the second hydraulic oil port 572 of the hydraulic valve 57 and the brake oil return circuit 51, and the control oil port of the relief valve 61 is connected to the second switch oil port 5342 of the second hydraulic stroke switch valve 534. Specifically, the relief pressure of the relief valve 61 is greater than the opening pressure of the brake 55 to ensure that the brake 55 can be opened smoothly. Specifically, the relief pressure of the relief valve 61 can be 3-5 Mpa, and the opening pressure of the brake 55 can be less than 2.5 Mpa.

[0043] In this embodiment, the main control circuit further includes a two-way balance valve 41. The two-way balance valve 41 includes a first balance valve provided in the first working oil circuit 36 and a second balance valve provided in the second working oil circuit 37. The pilot oil circuit of the sequence valve in the first balance valve is connected to the second working oil circuit 37, and the pilot oil circuit of the sequence valve in the second balance valve is connected to the first working oil circuit 36. Those skilled in the art can understand that setting this two-way balance valve 41 can enhance the operation of the telescopic motor 21 to be more stable, safer and more reliable.

[0044] In this embodiment, the telescopic control device may further include a swing control valve 71 for controlling the swing of the telescopic mechanism. The oil inlet and oil return port of the swing control valve 71 are respectively connected to the main control pressure oil circuit 30 and the main control oil return circuit 31; and / or, the telescopic control device may further include a luffing control valve 73 for controlling the luffing of the telescopic mechanism. The oil inlet and oil return port of the luffing control valve 73 are respectively connected to the main control pressure oil circuit 30 and the main control oil return circuit 31. That is, the telescopic control can be integrated with the swing or luffing control system and does not affect each other.

[0045] Taking the aerial ladder fire truck as an example, in combination with Figures 3 to 7, specifically describe the operation process and principle of the telescopic control device. Among them, the telescopic motor 21 drives the wire rope wound around the winch to drive the telescopic movement of the ladder frame. The telescopic motor 21 is pressed by the brake 55 in the initial state and cannot rotate. The brake 55 can only be released under the action of pressure oil to enable the telescopic motor 21 to rotate. The telescopic control valve 33, the slewing control valve 71, and the luffing control valve 73 are respectively the directional control valves for the telescopic movement, slewing, and luffing of the ladder frame.

[0046] Please refer to Figure 3 , which shows the state diagram of the telescopic control device when the telescopic mechanism extends. At this time, the pressure oil passes through the main control pressure oil circuit 50, passes through the pressure reducing valve 59, and reaches the brake valve 52. The pressure oil in the first working oil circuit 36 also passes through the shuttle valve 39 and reaches the control oil port of the brake valve 52. After the pressure exceeds the spring opening pressure of the brake valve 52, it pushes the brake valve 52 to change its position. The brake valve 52 is in the right position. The pressure oil passes through the brake valve 52 and reaches the first hydraulic stroke switch valve 532. The first hydraulic stroke switch valve 532 has not reached the limit position and is in the right position, enabling the pressure oil to reach the brake 55 and open the brake 55 to release the brake. At the same time, operate the telescopic control valve 33 to be in the right position. The pressure oil is transported from the main control pressure oil circuit 30 through the telescopic control valve 33 to the first working oil circuit 36. The hydraulic lock valve 35 is in the right position under the action of the spring force, and the first working oil circuit 36 is connected. The pressure oil reaches the first oil port A2 of the telescopic motor 21 through the first working oil circuit 36. Since the brake of the brake 55 is released at this time, the telescopic motor 21 can rotate forward and the ladder frame extends. The control oil port of the hydraulic valve 57 is connected to the second working oil circuit as the return oil circuit, and the back pressure is generally lower than 1 MPa. Therefore, the hydraulic valve 57 remains in the left position under the action of the spring force.

[0047] Please refer to Figure 4 , which shows the state diagram of the telescopic control device when the telescopic mechanism is fully extended. At this time, the first hydraulic stroke switch valve 532 and the second hydraulic stroke switch valve 534 reach the limit position due to the full extension of the ladder frame and thus switch to the left position. The pressure oil passes through the main control pressure oil circuit 50, passes through the pressure reducing valve 59, and reaches the second hydraulic stroke switch valve 534, and then reaches the first control oil port of the hydraulic lock valve 35 through the second hydraulic stroke switch valve 534. The hydraulic lock valve 35 switches to the left position, thereby disconnecting the first working oil circuit 36. The pressure oil in the main control pressure oil circuit 50 cannot reach the telescopic motor 21, and the telescopic motor 21 cannot rotate. At the same time, the pressure oil of the brake 55 is drained through the first hydraulic stroke switch valve 532, the hydraulic valve 57 and the brake return oil circuit 51, and the brake 55 is braked. In this way, double locking is achieved to ensure the reliability of the braking after the ladder frame is fully extended. At the same time, both the first working oil circuit 36 and the second working oil circuit 37 are low-pressure oils, and the oil pressure at the output oil port of the shuttle valve 39 is relatively low. The brake valve 52 returns to the left position under the action of the spring force.

[0048] Please refer toFigure 5 , which shows the state diagram of the telescopic control device when the telescopic mechanism is extended and the ladder frame rotates or luffs. At this time, the ladder frame is still in the fully extended state, the first hydraulic stroke switch valve 532 and the second hydraulic stroke switch valve 534 are still in the left position, and the ladder frame is protected by the hydraulic lock valve 35. At this time, if the ladder frame is operated to rotate or luff, the generated back pressure is generally less than 1 Mpa, and the hydraulic valve 57 and the brake valve 52 are still in the left position for operation, and the entire telescopic circuit of the ladder frame will not be affected.

[0049] Please refer Figure 6 , which shows the state diagram of the telescopic control device when the telescopic mechanism starts to retract. At this time, the first hydraulic stroke switch valve 532 and the second hydraulic stroke switch valve 534 have not disengaged from the wedge block, so they are still in the left position. Operate the telescopic control valve 33 to the left position. On the one hand, the pressure oil is delivered through the main control pressure oil circuit 50, through the telescopic control valve 33, to the second working oil circuit 37, and then to the control oil port of the hydraulic valve 57, pushing the hydraulic valve 57 to switch to the right position. The pressure oil in the second working oil circuit 37 is also delivered to the control oil port of the brake valve 52 through the shuttle valve, pushing the brake valve 52 to switch to the right position. In this way, the pressure oil passes through the brake pressure oil circuit 50, through the pressure reducing valve 59, to the brake valve 52, and the pressure oil passes through the hydraulic valve 57 to the brake 55 and opens the brake 55 to release the brake. At the same time, the pressure oil is delivered through the main control pressure oil circuit 30, through the telescopic control valve 33, to the second working oil circuit 37, and then to the second oil port B2 of the telescopic motor 21. Since the brake of the brake 55 is released at this time, the telescopic motor 21 can be reversed, and the ladder frame starts to retract; the pressure oil is also delivered from the second working oil circuit 37 to the second control oil port of the hydraulic lock valve 35, pushing the hydraulic lock valve 35 to switch to the right position, and the first working oil circuit 36 is connected to form the oil return oil circuit of the main control loop.

[0050] Please refer Figure 7 , which shows the state diagram of the telescopic control device during the complete retraction of the telescopic mechanism. At this time, the ladder frame further retracts, and the first hydraulic stroke switch valve 532 and the second hydraulic stroke switch valve 534 disengage from the wedge block, so they switch to the right position under the action of the spring force. The pressure oil passes through the main control pressure oil circuit 50, through the pressure reducing valve 59, to the brake valve 52, and the pressure oil in the first working oil circuit 36 also passes through the shuttle valve 39 to the control oil port of the brake valve 52. After the pressure exceeds the spring opening pressure of the brake valve 52, it pushes the brake valve 52 to reverse, and the brake valve 52 is in the right position. The pressure oil passes through the brake valve 52 to the first hydraulic stroke switch valve 532, and the pressure oil reaches the brake 55 and opens the brake 55 to release the brake. At the same time, the pressure oil is delivered through the main control pressure oil circuit 30, through the telescopic control valve 33, to the second working oil circuit 37, and then to the second oil port B2 of the telescopic motor 21. Since the brake of the brake 55 is released at this time, the telescopic motor 21 can be reversed, and the ladder frame continues to retract until it is completely retracted.

[0051] The present invention further provides a construction machine, which includes a telescopic mechanism and the above-mentioned telescopic control device. The telescopic control device at least controls the telescoping of the telescopic mechanism. The construction machine may be the aerial ladder fire truck in this embodiment, and the telescopic mechanism is the telescopic ladder frame. The telescopic mechanism may also be other construction machines, such as the telescopic boom in a crane, etc.

[0052] It should be noted that the various embodiments in this specification are all described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same and similar parts among the various embodiments, reference may be made to each other.

[0053] As described above, the above are only the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. A telescopic control device, characterized in that, It includes a main control circuit, a brake control circuit and a telescopic motor (21). The main control circuit includes a main control pressure oil circuit (30) and a main control oil return circuit (31). A telescopic control valve (33) and a hydraulic lock valve (35) are provided on the main control circuit. The telescopic control valve (33) is used to switch and control the forward rotation, reverse rotation or stop of the telescopic motor (21). The brake control circuit includes a brake pressure oil circuit (50) and a brake oil return circuit (51). A brake valve (52), a hydraulic travel switch valve (53) and a brake (55) are provided on the brake control circuit. The brake pressure oil circuit (50) is used to supply pressure oil to the brake (55). The brake valve (52) and the hydraulic travel switch valve (53) are used to control the connection or disconnection between the brake pressure oil circuit (50) and the brake (55), and are used to control the connection or disconnection between the brake oil return circuit (51) and the brake (55). The brake valve (52) and the hydraulic travel switch valve (53) are also used to control the commutation of the hydraulic lock valve (35) to disconnect the main control pressure oil circuit (30) of the main control circuit from the telescopic motor (21) when the brake pressure oil circuit (50) is disconnected from the brake (55).

2. The telescopic control device according to claim 1, characterized in that, The telescopic control valve (33) further includes a pressure oil port (P1), an oil return port (T1), a first working oil port (A1) and a second working oil port (B1). The telescopic motor (21) includes a motor first oil port (A2) and a motor second oil port (B2). The main control circuit further includes a first working oil circuit (36) and a second working oil circuit (37). The pressure oil port (P1) is connected to the main control pressure oil circuit (30). The oil return port (T1) is connected to the main control oil return circuit (31). The first working oil circuit (36) is connected between the first working oil port (A1) and the motor first oil port (A2). The second working oil circuit (37) is connected between the second working oil port (B1) and the motor second oil port (B2). The hydraulic lock valve (35) is provided on the first working oil circuit (36) and connects the first working oil circuit (36) when the hydraulic travel switch valve (53) connects the brake (55) to the brake pressure oil circuit (50), and disconnects the first working oil circuit (36) when the hydraulic travel switch valve (53) disconnects the brake (55) from the brake pressure oil circuit (50).

3. The telescopic control device according to claim 2, wherein The hydraulic lock valve (35) includes a first position and a second position. When the hydraulic lock valve (35) is in the first position, the first working oil passage (36) is connected. When the hydraulic lock valve (35) is in the second position, the first working oil passage (36) is disconnected, and the hydraulic lock valve (35) connects the first oil port (A2) of the motor to the second working oil passage (37). The hydraulic lock valve (35) includes a first control oil port and a second control oil port. The first control oil port is connected to the hydraulic travel switch valve (53), and the position of the hydraulic lock valve (35) is switched according to the position of the hydraulic travel switch valve (53) so that the hydraulic lock valve (35) is in the second position. The second control oil port is connected to the second working oil passage (37), and the position of the hydraulic lock valve (35) is switched when the second working oil passage (37) is connected to the main control pressure oil passage (30) so that the hydraulic lock valve (35) is in the first position.

4. The telescopic control device according to claim 3, wherein The hydraulic travel switch valve (53) includes a first hydraulic travel switch valve (532) and a second hydraulic travel switch valve (534). The brake valve (52) is connected between the first hydraulic travel switch valve (532) and the brake pressure oil passage (50). The first hydraulic travel switch valve (532) is connected to the brake (55). The brake valve (52) is used to connect or disconnect the first hydraulic travel switch valve (532) from the brake pressure oil passage (50). The first hydraulic travel switch valve (532) is used to connect or disconnect the brake valve (52) from the brake (55). The second hydraulic travel switch valve (534) is connected to the brake pressure oil passage (50), and the second hydraulic travel switch valve (534) is also connected to the first control oil port of the hydraulic lock valve (35). The second hydraulic travel switch valve (534) is used to connect or disconnect the brake pressure oil passage (50) from the first control oil port of the hydraulic lock valve (35) to control the position switching of the hydraulic lock valve (35).

5. The telescopic control device according to claim 4, characterized in that A shuttle valve (39) is provided between the first working oil passage (36) and the second working oil passage (37). The control oil port of the brake valve (52) is connected to the oil outlet of the shuttle valve (39) to control the position switching of the brake valve (52). When any one of the first working oil passage (36) and the second working oil passage (37) is high-pressure oil, the brake valve (52) connects the first hydraulic travel switch valve (532) to the brake pressure oil passage (50). When both the first working oil passage (36) and the second working oil passage (37) are low-pressure oil, the brake valve (52) disconnects the first hydraulic travel switch valve (532) from the brake pressure oil passage (50).

6. The telescopic control device according to claim 5, wherein A hydraulic valve (57) is also provided on the brake control circuit. One end of the hydraulic valve (57) is connected to the brake (55), and the other end is respectively connected to the brake valve (52) and the brake oil return circuit (51). The hydraulic valve (57) is used to connect or disconnect the brake (55) from the brake pressure oil circuit (50). The control oil port of the hydraulic valve (57) is connected to the second working oil circuit (37), and when the second working oil circuit (37) is connected to the main control pressure oil circuit (30), it switches to the position of connecting the brake (55) to the brake pressure oil circuit (50). The hydraulic valve (57) is also used to connect or disconnect the brake (55) from the brake oil return circuit (51), and when the second working oil circuit (37) is disconnected from the main control pressure oil circuit (30) and the hydraulic stroke switch valve (53) disconnects the brake (55) from the brake pressure oil circuit (50), it connects the brake (55) to the brake oil return circuit (51).

7. The telescopic control device according to claim 6, wherein The brake valve (52) includes a first brake oil port (522), a second brake oil port (524), and a third brake oil port (526). When the position of the brake valve (52) is switched, the third brake oil port (526) communicates with the first brake oil port (522) or the second brake oil port (524). The first brake oil port (522) is connected to the brake pressure oil circuit (50), and the second brake oil port (524) is connected to the brake oil return circuit (51). The brake valve (52) includes a first position and a second position. When the brake valve (52) is in the first position, the first brake oil port (522) is communicated with the third brake oil port (526), and when in the second position, the second brake oil port (524) is communicated with the third brake oil port (526). The hydraulic valve (57) includes a first hydraulic oil port (571), a second hydraulic oil port (572), a third hydraulic oil port (573), and a fourth hydraulic oil port (574). The first hydraulic oil port (571) is connected to the third brake oil port (526) of the brake valve (52), the second hydraulic oil port (572) is connected to the brake oil return circuit (51), the third hydraulic oil port (573) is connected to the brake (55), and the fourth hydraulic oil port (574) is connected to the second hydraulic stroke switch valve (534). When the position of the hydraulic valve (57) is switched, it communicates the brake (55) with the brake valve (52), or communicates the second hydraulic stroke switch valve (534) with the brake oil return circuit (51). The second hydraulic stroke switch valve (534) includes a first switch oil port (5341), a second switch oil port (5342), and a third switch oil port (5343). The first switch oil port (5341) is connected to the brake pressure oil circuit (50), the second switch oil port (5342) is connected to the fourth hydraulic oil port (574) of the hydraulic valve (57), and the third switch oil port (5343) is connected to the first control oil port of the hydraulic lock valve (35). When the position of the second hydraulic stroke switch valve (534) is switched, it communicates the first switch oil port (5341) with the first control oil port of the hydraulic lock valve (35), or communicates the second switch oil port (5342) with the first control oil port of the hydraulic lock valve (35). The first hydraulic stroke switch valve (532) includes a fourth switch oil port (5322), a fifth switch oil port (5323), and a sixth switch oil port (5324). The fourth switch oil port (5322) is connected to the third brake oil port (526) of the brake valve (52), the fifth switch oil port (5323) is connected to the fourth hydraulic oil port (574) of the hydraulic valve (57), and the sixth switch oil port (5324) is connected to the brake (55);When the first hydraulic travel switch valve (532) is in the switching position, it connects the fourth switch oil port (5322) to the sixth switch oil port (5324), or connects the fifth switch oil port (5323) to the sixth switch oil port (5324).; 8. The telescopic control device according to claim 7, characterized in that, A pressure reducing valve (59) is also provided on the brake control circuit. The inlet oil port of the pressure reducing valve (59) is connected to the brake pressure oil circuit (50), the outlet oil port of the pressure reducing valve (59) is connected to the first brake oil port (522) of the brake valve (52), and the control oil port of the pressure reducing valve (59) is connected to the first brake oil port (522) of the brake valve (52). The outlet pressure of the pressure reducing valve (59) is greater than the spring pressure of the hydraulic lock valve (35). An overflow valve (61) is also provided on the brake control circuit. One working oil port of the overflow valve (61) is connected to the second switch oil port (5342) of the second hydraulic stroke switch valve (534), and the other working oil port is connected to the second hydraulic oil port (572) of the hydraulic valve (57) and the brake oil return circuit (51). The control oil port of the overflow valve (61) is connected to the second switch oil port (5342) of the second hydraulic stroke switch valve (534). The main control circuit further includes a two-way balance valve (41). The two-way balance valve (41) includes a first balance valve provided in the first working oil circuit (36) and a second balance valve provided in the second working oil circuit (37). The pilot oil circuit of the sequence valve in the first balance valve is connected to the second working oil circuit (37), and the pilot oil circuit of the sequence valve in the second balance valve is connected to the first working oil circuit (36).

9. The telescopic control device according to claim 1, characterized in that, The telescopic control device may further include a slewing control valve (71) for controlling the slewing of the telescopic mechanism. The inlet oil port and the return oil port of the slewing control valve (71) are respectively connected to the main control pressure oil circuit (30) and the main control oil return circuit (31); and / or, the telescopic control device may further include a luffing control valve (73) for controlling the luffing of the telescopic mechanism. The inlet oil port and the return oil port of the luffing control valve (73) are respectively connected to the main control pressure oil circuit (30) and the main control oil return circuit (31).

10. An engineering machinery, characterized in that, The construction machinery includes a telescopic mechanism and the telescopic control device according to any one of claims 1-9, and the telescopic control device at least controls the telescoping of the telescopic mechanism.

Images