WO2014168540A1

WO2014168540A1 - System for controlling a quick coupling arranged at a tool arm

Info

Publication number: WO2014168540A1
Application number: PCT/SE2014/000036
Authority: WO
Inventors: Niklas Bjuhr
Original assignee: Indexator Group Ab
Priority date: 2013-04-09
Filing date: 2014-04-04
Publication date: 2014-10-16

Abstract

The present invention relates to a system (100) for controlling a quick coupler (101); which quick coupler is arranged at an tool arm and is arranged to assume a locked position in which at least one tool/accessory is locked to the tool arm and an unlocked position in which the tool/accessory is detached from the tool arm, which system comprises a first control unit (111) arranged to receive an input signal S1 and, after a first checking procedure (CM1), to output a first control signal S1 to at least one control means (121, 122), the system further comprises a second separate control unit (112) arranged to receive the input signal S1 and, after a second separate checking procedure (CM2), to output a second control signal S2 to the control means (121, 122), wherein the control means (121, 122) is arranged to control the quick coupler (101) to the unlocked position if the first control signal S1 and the second control signal S2 both indicate a value (V1, V2) which correspond to a valid signal for the unlocked position. Furthermore, the invention relates to a machine comprising such a system.

Description

SYSTEM FOR CONTROLLING A QUICK COUPLING ARRANGED AT A TOOL ARM Technical field

The present invention relates to a system for controlling a quick coupler. Furthermore, the present invention relates to a machine comprising such a system.

Background of the invention

It is common that certain types of heavy machines such as excavators, forestry machines and wood-working machines have a tool arm on which one or several tools/accessories may be attached by means of a so-called quick coupler. In that way useful tools/accessories may be locked and detached, respectively, quickly from the tool arm. Usually, such a quick coupler may be positioned in a locked position in which at least one tool/accessory is locked to the tool arm and an unlocked position in which the tool/accessory is detached from the tool arm. The Swedish patent application 1200605-2 describes such a machine with an tool arm as described above. In Fig. 1 a tool arm/work arm or a shaft 2 on, in this example an excavator, which work arm 2 supports an upper attachment part 10A for mounting of a manoeuvring device 15, which in the shown example comprises a combined rotational device and tilting device. The manoeuvring device 15 exhibits an upper attachment part 10B for holding interaction with the upper fastening part 10A on the work arm 2. The manoeuvring device 15 also supports a lower attachment part 16A for holding interaction with an attachment part 16B of a work accessory which in the shown case is constituted by a bucket 5 but may be any other suitable accessory or tool. The manoeuvring device 15 constitutes an example on an intermediate part 20 which is mounted between the work arm 2 and the work accessory 5 in order to increase the movability of the work accessory 5. It should be understood that this series connected intermediate part 20 may be designed in many different ways and exhibit a number of different additional qualifications. The intermediate part may of course be omitted when no additional qualifications are desired and then direct coupling between the guest parts 10A and 16B occurs. As is evident from the mentioned figures the attachment part 10B of the intermediate part 20 comprises two parallel attachment pins 30, 31, which are arranged to fit in corresponding recesses 40, 41, which are arranged in the attachment part 10A of the work frame 2. In the corresponding way the attachment part 16B of the work accessory 5 exhibits two parallel attachment pins 30, 31, which are arranged in the corresponding way as the previously mentioned attachment pins 30, 31. The attachment pins 30, 31, fit in the corresponding recesses 40, 41, which are arranged in the attachment part 16A.

From the above it should be realized that the work accessory 5 may be directly coupled without the intermediate part 20 by direct engagement between the attachment parts 10A and 16B. Fig. 3-5 illustrate the structure of a concurrent pair of attachment parts as for example might be 10A+10B, 16A-16B or 10A-16B.

In Fig. 3 a coupling phase between for example an upper attachment part 10A of a work frame 2 and a lower attachment part 16B of for example a work accessory 5 is shown. The attachment part 10A exhibits two first recesses 41 which engages the fastening pin 31 and at the same time allows a slewing motion between the parts 10A and 16B around the attachment pin 31. A coupling operation (or locking operation) is normally initiated with a manoeuvring to the just mentioned engagement (see Fig. 3). Then a slew manoeuvring occurs so that the fastening pin 30 reaches the bottom of two other recesses 40 of the attachment part 10A. Then a locking of the attachment parts 10A and 16A occurs by manoeuvring a locking wedge 50 forward from a starting position according to Fig 4 to a locking position according to Fig. 5. The wedge manoeuvring normally occurs with a double acting hydraulic cylinder 51. From Fig. 5 it is evident that the locking wedge 50 fixates the fastening pin 30 in the recesses 40 at the same time as the attachment pin 31 is fixated in the recesses 41. The above described scenario results in a very secure locking provided that the locking wedge 50 ends up in correct contact with the attachment pin 30, which unfortunately is not always the case. The just mentioned may result in accessory detachment where a falling accessory run the risk of causing damages on personnel as well as on material. At detachment of an accessory the above described coupling is inverted wherein the locking wedge 50 is again manoeuvred to its starting position according to Fig. 4. Fig. 6 illustrates a system for controlling a just mentioned quick coupler according to the prior art. The system comprises a so called control unit which receives a manoeuvring signal, generated by, e.g., an operator when he wants to lock and detach, respectively, a tool from the tool arm. After the realization of a checking procedure a control signal is sent to a control means which controls the quick coupler between a locked position and an unlocked position depending of the instruction of the manoeuvring signal and the result of the checking procedure.

One problem with such systems according to the prior art is that the quick coupler may assume or be brought to the locked position unintentionally, due to e.g., signalling error, drift in electronics, etc. Furthermore, regulating requirements exist, which have to be fulfilled, regarding safety requirements for quick couplers of the described type and the legislators within EU have for example prepared new stricter rules regarding this type of safety, why also a new ISO-standard will be in force from 2014.

Summary

An objective of the present invention is to provide a solution which entirely or partly solves problems and/or drawbacks with known solutions for controlling a quick coupler. Specifically, the present invention aims to provide a system with which the safety for quick couplers according to the above is improved.

According to an aspect of the invention the above objects are fulfilled with a system for controlling a quick coupler, which quick coupler is arranged at a tool arm and is arranged to assume a locked position in which at least one tool/accessory is locked to the tool arm and an unlocked position in which the tool/accessory is detached from the tool arm; which system comprises a first control unit arranged to receive an input signal Si and, after a first checking procedure, output a first control signal S I to at least one control means; wherein the system further comprises a second separate control unit arranged to receive the input signal Si and, after a second separate checking procedure, to output a second control signal to the control means, wherein the control means is arranged to control the quick coupler to the unlocked position if the first control signal SI and the second control signal S2 both indicate a value which corresponds to a valid signal for the unlocked position. Different embodiments of the system above are defined in the appended independent claims related to the system. Furthermore, the invention also relates to a machine comprising at least one system according to the invention. A system according to the present invention provides a solution which improves the security when using a quick coupler. In that way the risk for accidents is reduced significantly and furthermore, damage on material may be reduced as unintentional detachment of accessories is decreased. Furthermore, the present invention fulfils the requirements of new sets of safety rules and regulations.

Additional advantages and applications of the invention will be evident from the following detailed description.

Short description of the drawings

The present invention is described with reference to the appended drawings in which:

Fig. 1 shows in a perspective view a pointed portion of an accessory arm/work arm (stick) of an excavator, which arm via two accessory attachments support coupled fittings/accessories;

Fig. 2 corresponds to Fig. 1 except for that the accessory attachments are uncoupled so that the fittings/accessories are detached;

Fig. 3 shows a schematical longitudinal cut through an accessory attachment during a coupling phase;

Fig. 4 shows a schematical longitudinal cut through the accessory attachment when the attachment is put together to a real end position but not coupled;

Fig. 5 shows the accessory attachment after finished coupling;

Fig. 6 illustrates a system for controlling a quick coupler according to the prior art;

Fig. 7 illustrates an embodiment of a system according to the invention;

Fig. 8 illustrates another embodiment of a system according to the invention;

Fig. 9 shows a system outline of an embodiment of a system according to the invention;

Fig. 10A shows a block diagram over the first control unit (CCU);

Fig. 10B shows a block diagram over the second control unit (TCU); Fig. 11 illustrates a further embodiment of the invention; and

Fig. 12 shows two parallel checking sequences according to an embodiment.

Detailed description of the invention

With an aim of reaching the objectives mentioned above the present invention relates to a system 100 for controlling a quick coupler 101 for an accessory arm/work arm. The quick coupler is arranged on a tool arm and is arranged to be positioned in a locked position in which at least one tool/accessory is locked to the tool arm and an unlocked position in which the tool/accessory is detached or may be detached from the tool arm. Thus, the function of the quick coupler is to lock and detach, respectively, an accessory to/from the tool arm. Furthermore, it should be noted that there are quick couplers with which several tools may be locked to the tool arm.

With reference to Fig. 7 the present system for controlling a quick coupler comprises a first control unit 1 11 arranged to receive an input signal Si and, after a first checking procedure CM1, to output a first control signal S I to one or several control means 121, 122. The input signal S 1 is typically an electric signal (but may be any other type of suitable signal) which initiates the checking procedure and may for example be provided over a communication bus system. As has been mentioned above the input signal may be generated and sent from a manoeuvring or terminal unit manoeuvred by the operator of the machine when this person wants the quick coupler to be brought to the locked or unlocked position depending on a present position of the quick coupler. Essentially the input signal may therewith be interpreted as an instruction to "open" (bring to an unlocked position) or "close" (bring to a locked position) the quick coupler.

The checking procedure or function means that a number of conditions are checked so that they are fulfilled before a control signal is sent to the control means. The value of the control signal thus becomes a result of the value of the input signal and the result of the checking procedure.

Furthermore, the present system comprises a second control unit 112 separated from the first control unit 111. The second control unit is arranged to receive the input signal Si and, after a second separate checking procedure CM2, to output a second control signal S2 to the control means 121, 122. The control means 121, 122, is in turn arranged to control the quick coupler 101 to the unlocked position only if the first control signal S I and the second control signal S2 both indicate a value VI and V2, respectively, which correspond to a valid signal for the unlocked position.

With a valid signal is understood that the control means gets an instruction which means that the quick coupler is to be controlled to the unlocked position. Logically this may be represented as VI = V2 = True = "quick coupler in unlocked position". The signalling may for example take place in that a "high" voltage signal indicates True, or vice versa depending on how the system is programmed. Furthermore, it is understood that the system according to the invention also uses the condition that the operation for the quick coupler to be controlled to the unlocked position requires that VI = True AND V2 = True, i.e. a logical AND operation. The first checking procedure CM1, which is performed by the first control unit, means checking that a first group of conditions are fulfilled. In the corresponding way the second checking procedure CM2, which is performed by the second control unit, means checking that a second group of conditions are fulfilled. It should be noted that the first and second group of conditions are not identical according to a preferred embodiment of the invention.

With the present redundant system with separate control units and separate checking procedures and logical AND conditions of received control signals a system with improved safety, compared to systems according to the prior art, is provided. The risk that the quick coupling unintentionally is positioned in the unlocked position is then reduced significantly with the present invention.

Fig. 8 shows a further preferred embodiment of the invention in which the system in this case comprises two entirely separate control means, i.e. a first 121 and a second 122 control means. They are independent of each other and consist of separate hardware units as is shown in Fig. 8. The first control member is connected to the first control unit 11 1 and is arranged to receive the first control signal S I in contrast to the second control member 122, which instead is connected to the second control unit 1 12 and is arranged to receive the second control signal S2. According to this embodiment the quick coupler 101 is positioned in the unlocked position only if the first control means has been controlled to the desired position at the same time as the second control means has been controlled to the desired position. An example on such a solution is if the quick coupler is manoeuvred hydraulically and the two control means are hydraulic valves arranged in such a way in the hydraulic system that both must be positioned in a respective given valve position in order for the quick coupler to be brought to the unlocked position due to a controlled hydraulic flow. This embodiment is illustrated also in Fig. 10 and 11.

The quick coupler may further comprise at least one locking wedge 50 with which the accessory or the tool is locked to the accessory arm in the locked position. The locking wedge is manoeuvred by means of at least one hydraulic cylinder 51, which has been described above. According to this embodiment the tool arm comprises preferably also a hydraulically controlled rotational device (rotator), or a combined rotational and tilting device (tiltrotator), with which the accessory/tool may be rotated around a rotational axis, and be rotated around a rotational axis and be tilted around a tilting axis, respectively. According to this embodiment the present system is thereby arranged to control a quick coupler for a rotator or tiltrotator.

According to the above embodiment the first control unit 111 may be a cabin control unit (sometimes also called CCU, "Cabin Control Unit") or similar, i.e. a control unit for controlling various functions in relation to the driver cabin or operator cabin on a machine. Furthermore, the second control unit 112 is a control unit for the rotational device or the combined rotational and tilting device (sometimes also called TCU, "Tiltrotator Control Unit"). The advantage with this solution is that there are already two existing separate control units on the machine which may be used as separate control units according to the present invention. This reduces the cost as no new hardware has to be installed in the machine. With respect to the checking procedures the first checking procedure CM1 means checking that a first group of conditions are fulfilled and in the corresponding way it is valid that the second checking procedure CM2 means checking that a second group of conditions are fulfilled. The conditions in the first and the second group need not be identical which has been mentioned earlier. According to an embodiment they are not identical. The checking, which takes place in each checking procedure, may concern checking of voltage levels at different units in the control system in a certain sequence, etcetera. Fig. 10A and Fig. 10B illustrate block diagrams for the CCU and the TCU, respectively, in the system.

In order to further improve the safety the system according to the invention is further arranged so that the first and second control unit may communicate with each other, for example with a CAN bus (CAN-bus", i.e., "Controller Area Network bus"), which is also shown in Fig. 8, 10A, 10B and 1 1. Thereby the two control units may cross-check each other. This may take place by that one or several of the conditions in the first group for the first checking procedure is that a valid value (OK) has been provided from the second control unit and inversely that one of the conditions in the second group for the second checking procedure is that a valid value (OK) has been provided from the first control unit. By that the risk that the control members get an invalid control signal from the first and the second control unit, respectively, is decreased even more. Fig. 11 shows how the CCU and the TCU are connected with the CAN bus for communication between them but otherwise are separated from each other.

Fig. 12 shows an example on checking sequences for the CCU and the TCU, respectively, which coordinated are executed for cross-checking. The left checking sequence concerns the CCU and for each loop holds for this example:

• Reception of sampled input;

• (Armed) Is the locking sequence initiated? If NO send an NOK (not valid signal) to the TCU and output "invalid" control signal, if YES continue sequence;

• (SW1) Is input 1 of SW1 (the switch of the lock in the panel) activated? If NO send an NOK to the TCU and output an "invalid" control signal, if YES continue sequence;

• (01) Is output 1 OK (monitored against short circuit, unfamiliar voltage and short circuit)? If NO send an NOK to the TCU and output "invalid" control signal, if YES continue sequence;

• (TCU OK) Is TCU OK (valid signal)? If NO send an NOK to the TCU and output "invalid" control signal, if YES continue sequence;

• (Buzzer OK) Is Buzzer OK (monitored against cable/circuit failure)? If NO send an NOK to the TCU and output "invalid control signal", if YES send an OK to the TCU and output "invalid control signal", if YES send an OK to the TCU och output a "valid" control signal to the control member.

The right checking sequence concerns the TCU and for each loop holds for this example:

• Reception of sampled input;

• (SW2) Is input 2 of SW2 (the switch of the lock in the panel) activated? If NO send an NOK to the CCU and output "invalid" control signal, if YES continue sequence;

• (02) Is output 2 OK? If NO send an NOK to the CCU and output "invalid" control signal, if YES send OK to the CCU;

• (CCU OK) Is CCU OK? If NO output "invalid" control signal, if YES output "valid" control signal to the control member.

It should be noted that SWl, Ol, SW2, Buzzer and 02 may be other suitable checking conditions than the ones mentioned above depending on the application.

Fig. 9 shows a system overview over a further embodiment of the present invention. The CCU and the TCU are according to this embodiment in communication with each other via a CAN bus so that they may cross-check each other. Furthermore, a terminal unit (HMI) is also connected on the bus. It is also shown in Fig. 9 that the CCU and the TCU are connected to different control means. Various input signals from different functions of the machine, such as rotator, tilt, pulse functions, etcetera, are also shown in Fig. 9. In Fig. 1 1 is shown how the CCU and the HMI belong to the subsystem "cabin" while the TCU belong to the system "tiltrotator". By that also the two control units are well separated spatially from each other which further decreases the probability that both units simultaneously would function incorrectly due to, e.g., outer mechanical, electrical, thermal, or other influence or damage. It is also clear from Fig. 1 1 how the CCU and the TCU are connected to different control members via separate communication paths and how they between themselves may communicate via the CAN bus.

Further, the invention relates to a machine which comprises at least one system according to any of the above embodiments. Examples on machines are an excavator, forestry machine or woodwork machine, but also other types of machines may use a system according to the invention which is readily appreciated by the person skilled in the art. According to an embodiment of the machine it further comprises at least one quick coupler and/or at least one tool arm as described above.

Finally, it should be appreciated that the present invention is not limited to the above described embodiments of the invention but is directed towards and comprises all embodiments within the scope of the appended independent claims.

Claims

1. System (100) for controlling a quick coupler (101); which quick coupler is arranged at an tool arm and is arranged to assume a locked position in which at least one tool/accessory is locked to the tool arm and an unlocked position in which the tool/accessory is detached from the tool arm, which system comprises a first control unit (1 11) arranged to receive an input signal Si and, after a first checking procedure (CM1), to output a first control signal SI to at least one control means (121, 122), characterized in that the system further comprises a second separate control unit (112) arranged to receive the input signal Si and, after a second separate checking procedure (CM2), to output a second control signal S2 to the control means (121, 122), wherein the control means (121, 122) is arranged to control the quick coupler (101) to the unlocked position if the first control signal S I and the second control signal S2 both indicate a value (V 1 , V2) which correspond to a valid signal for the unlocked position.

2. System according to claim 1, wherein the first checking procedure (CM1) means checking that a first group of conditions are fulfilled; and the second checking procedure (CM2) means checking that a second group of conditions are fulfilled; which first and second group of conditions are not identical to each other.

3. System according to claim 2, wherein the first control unit (111) and the second control unit (112) are arranged to communicate with each other; and the first group of conditions comprises checking that at least one valid signal has been provided from the second control unit (112), and the second group of conditions comprises checking that at least one valid signal has been provided from the first control unit (1 11).

4. System according to any one of the preceding claims, wherein the system comprises two separate control means (121; 122), a first control means (121) and a second control means (122); which first control means is connected to the first control unit (111) and is arranged to receive the first control signal S I, and which second control means (122) is connected to the second control unit (112) and is arranged to receive the second control signal S2; and the quick coupler (101) is brought to the unlocked position when the first control means and the second control means have been brought to desired positions simultaneously.

5. System according to claim 4, wherein the quick coupler (101) comprises at least one locking wedge (50) with which the tool/accessory is locked to the tool arm in the locked position, wherein the locking wedge is manoeuvred by means of at least one hydraulic cylinder (51).

6. System according to claim 5, wherein the first (121) and the second (122) control means are hydraulic valves connected to the hydraulic cylinder via a hydraulic system.

7. System according to any one of the preceding claims, wherein the tool arm comprises a hydraulically controlled rotational device or a combined rotational- and tilting device with which the tool/accessory may be rotated around a rotational axis, and be rotated around a rotational axis and tilted around a tilting axis, respectively.

8. System according to any one of the preceding claims, wherein the first control unit (111) is a cabin control unit (CCU) and the second control unit (112) is a control unit arranged for controlling the rotational device or the combined rotational and tilting device (TCU).

9. System according to any one of the preceding claims, wherein the input signal Si is a manoeuvre signal generated by an operator by means of a manoeuvring unit.

10. Machine, such as an excavator, a forestry machine or a wood-working machine, comprising at least one system according to any one of the preceding claims.

11. Machine according to claim 10, wherein the machine further comprises at least one quick coupler and/or at least one tool arm according to any one of claims 1-9.