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EP-4739849-A1 - TILTROTATOR WITH A PRESSURE MONITORING SYSTEM

EP4739849A1EP 4739849 A1EP4739849 A1EP 4739849A1EP-4739849-A1

Abstract

The invention relates to a pressure monitoring system for a tiltrotator (2), the tiltrotator (2) comprising a rotation motor (23), at least one tilting cylinder (24), a lower holder (5) for holding a tool (4), a locking block (10) for coupling a tool to said lower holder (5), a hydraulic cylinder (9) for actuating the locking block (10) between a closed and an open position, and a first valve (11) for controlling the hydraulic cylinder to actuate the locking block between the closed and the open position, wherein the pressure monitoring system comprises: a pressure sensor (7) for sensing a pressure (P') in a hydraulic line (11A) between the first valve (31) and a first pressure chamber (9A) of the hydraulic cylinder (9), a control unit (CU) configured to receive the sensed pressure (P') from the pressure sensor (7) and to verify that the first chamber (9A) of the hydraulic cylinder (9) is pressurised to push the locking block (10) towards the closed position based on the monitored pressure (P').

Inventors

  • BJUHR, NIKLAS
  • HOLGERSSON, Johnny

Assignees

  • Rototilt Group AB

Dates

Publication Date
20260513
Application Date
20240703

Claims (10)

  1. 1 . A tiltrotator (2) comprising a pressure monitoring system, the tiltrotator (2) further comprising a rotation motor (23), at least one tilting cylinder (24), a lower holder (5) for holding a tool (4), a locking block (10) for coupling a tool to said lower holder (5), a hydraulic cylinder (9) for actuating the locking block (10) between a closed and an open position, and a first valve (31 ) for controlling the hydraulic cylinder to actuate the locking block between the closed and the open position; wherein the pressure monitoring system comprises: a pressure sensor (7) for sensing a pressure (P’) in a hydraulic line (11A) between the first valve (31 ) and a first pressure chamber (9A) of the hydraulic cylinder (9), a control unit (CU) configured to receive the sensed pressure (P’) from the pressure sensor (7) and to verify that the first chamber (9A) of the hydraulic cylinder (9) is pressurised to push the locking block (10) towards the closed position based on the monitored pressure (P’), characterised in that the pressure monitoring system further comprises a position sensor (8) arranged to determine a position of the locking block (10) and to send a signal to the control unit (CU), the control unit (CU) being configured to verify that the locking block (10) is in the closed position based on a signal from the position sensor (8) and to provide a confirmation when the first chamber (9A) of the hydraulic cylinder (9) is pressurised and the locking block (10) is in the closed position.
  2. 2. The tiltrotator (2) according to claim 1 , wherein the control unit (CU) is configured to issue a positive verification when the control unit (CU) has verified that the locking block (10) is in the closed position based on a signal from the position sensor (7) and that the first chamber (9A) of the hydraulic cylinder (9) is pressurised towards the closed position based on the pressure sensed by the pressure sensor (7) and/or to issue a negative verification when the control unit (CU) has not verified that the locking block is in the closed position based on a signal from the position sensor, or that the hydraulic cylinder is not pressurised towards the closed position based on the pressure sensed by the pressure sensor.
  3. 3. The tiltrotator (2) according to claim 2, wherein the control unit (CU) may be connected to or form part of a controller of the work machine 1 , such that the work machine 1 and/or the tiltrotator 2 may be prevented or at least limited from being moved and/or from performing specific tasks when a negative verification has been issued by the control unit (CU) and/or when no positive verification has been issued by the control unit (CU).
  4. 4. The tiltrotator (2) according to any one of the preceding claims, wherein the pressure sensor (7) is arranged to monitor the pressure provided to the tiltrotator (2) during operation of the tiltrotator (2) to verify that the hydraulic pressure provided to the tiltrotator (2) is at a predetermined level, above a first threshold (T1) and below a second threshold (T2).
  5. 5. The tiltrotator (2) according to any one of the preceding claims, wherein the pressure sensor (7) is arranged to sense a return pressure between the first valve (31 ) and the first pressure chamber (9A) of the hydraulic cylinder (9) when the first valve (31) is positioned to control the hydraulic cylinder (9) to actuate the locking block (5) towards the open position and to send a signal thereof to the control unit (CU), the control unit (CU) being configured to monitor said return pressure.
  6. 6. The tiltrotator (2) according to any one of the preceding claims, wherein the pressure sensor (7) is arranged to sense the hydraulic pressure in the system and to send a signal thereof to the control unit, the control unit (CU) being configured to monitor the hydraulic pressure in the system and to receive information regarding the position of a first control valve (12) in the system for controlling a hydraulic function on or at the tiltrotator, and to monitor said hydraulic pressure in dependence of the position of at least one control valve, thereby enabling calibration the at least one control valve.
  7. 7. The tiltrotator (2) according to any one of the preceding claims, wherein the pressure sensor (7) is arranged in a hydraulic valve unit (6) also comprising the first valve (31).
  8. 8. The tiltrotator (2) according to claim 7, wherein the hydraulic valve unit (6) further comprises at least one other valve (32, 33, 34) arranged to control a hydraulic function (23) of the tiltrotator (2) and/or a hydraulic function (4, 16) arranged on the tiltrotator (2).
  9. 9. The tiltrotator (2) according to any one of the claims 1-6, wherein the pressure sensor (7) is arranged at the first pressure chamber (9A) of the hydraulic cylinder (9).
  10. 10. The tiltrotator (2) according to any one of the preceding claims, wherein the locking block (10) is biased towards the locked position.

Description

TILTROTATOR WITH A PRESSURE MONITORING SYSTEM TECHNICAL FIELD The invention relates to a tiltrotator comprising a pressure monitoring system. Specially, the invention relates to tiltrotator with a pressure monitoring system in which a pressure sensor is positioned to measure relevant operation pressures during different stages of the operation of the tiltrotator. BACKGROUND In forestry, construction work and the like it has become more and more common to utilise a tiltrotator at the outer end of a working arm of a work vehicle, such as an excavator. The tiltrotator has a lower holder for carrying a tool such as a compactor, hydraulic hammer, grapple, bucket etc. The tiltrotator simplifies the use of different tools as it is furnished with a hydraulic tool coupler for a simple change of tools and may provide both a tilting movement and an unlimited rotational movement of an attached tool. With a tiltrotator mounted on its arm the excavator becomes a more useful tool carrier in that the functionality of the tool is increased when mounted on a tiltrotator. A tiltrotator is provided with pressurised hydraulic fluid from a hydraulic pressure source to drive the tilting motor, which is normally comprised of two hydraulic cylinders, and the rotation motor comprised in the tiltrotator. Further, a tiltrotator is provided with a hydraulic swivel so as to drive the functions of a hydraulic tool arranged below the tiltrotator. In a conventional tiltrotator a first pair of hydraulic lines through the swivel may be provided to drive a hydraulic cylinder arranged to lock the tool to a tool coupler arranged at the lower part of the tiltrotator. A second pair of lines through the swivel are often provided to drive a grapple module, which may be a complementary part of the tiltrotator. Further, a third pair of lines through the swivel is provided to drive a function of a tool arranged below the tiltrotator. Nowadays it is common to exchange tools below the tiltrotator when different work operations are performed. During a normal work session several tool exchanges may be performed. A hydraulically manoeuvred locking block is normally arranged to lock and unlock the tool coupled to the tiltrotator. It goes without saying that it is very important that such exchanges may be made in a safe manner, in which the operator will be able to easily confirm that a tool exchange has been successfully made and that the tool is correctly attached to the tool coupler of the tiltrotator. Often, the locking block is biased towards the locked position such that it may end up in the locked position without that the operator has actively operated the locking block towards the locked position and without that the hydraulic cylinder controlling the locking block is pressurised towards the locked position. This results in a risk, because the operator may be led to believe that the locking block is secured in its position although it is not. This is especially risky if the locking block is provided with a position sensor arranged to provide a positive locking signal if the locking block is in its locking position. In EP 2 640 658 B1 a manoeuvring device is disclosed in which sensors are arranged to verify a correct position of a working tool below a manoeuvring device such as a tiltrotator. This invention has set a new standard for tiltrotators, and sensors are now implemented to verify a correct locked position of a working tool on most tiltrotators on the market. It would be advantageous to achieve an arrangement where a sensor solution for a tiltrotator could be combined with additional functionality without compromising the high security provided by such a sensor solution. SUMMARY OF THE INVENTION It is an object of the invention to provide a pressure monitoring system for a tiltrotator in which the safety is increased with respect to some conventional tiltrotators. According to a first aspect the invention relates to a tiltrotator comprising a pressure monitoring system for a tiltrotator, the tiltrotator further comprising: a rotation motor, at least one tilting cylinder, a lower holder for holding a tool, a locking block for coupling a tool to said lower holder, a hydraulic cylinder for actuating the locking block between a closed and an open position, and a first valve for controlling the hydraulic cylinder to actuate the locking block between the closed and the open position, wherein the pressure monitoring system of the tiltrotator comprises: a pressure sensor for sensing a pressure in a hydraulic line between the first valve and a first pressure chamber of the hydraulic cylinder, a control unit configured to receive the sensed pressure from the pressure sensor and to verify that the first chamber of the hydraulic cylinder is pressurised towards the closed position based on the monitored pressure. An advantage of the inventive solution is that one sensor may be arranged to provide different functionalities, which conventionally would r