WO2009094926A1

WO2009094926A1 - Tool quick coupler and machine using same

Info

Publication number: WO2009094926A1
Application number: PCT/CN2009/070176
Authority: WO
Inventors: Sean W. Johnson; Sixin Wang
Original assignee: Caterpillar Inc.
Priority date: 2008-01-24
Filing date: 2009-01-16
Publication date: 2009-08-06
Also published as: CN101492923A; CN101492923B

Abstract

A machine (10), such as a wheel loader, including an implement hydraulic system (60) that includes a hydraulic boom actuator (15) and a hydraulic bucket actuator (14) is provided with a tool quick coupler (30). The tool quick coupler assembly (30) carried by a chassis (11) of the machine (10) includes a hydraulic coupler actuator (35) fluidly connected to the implement hydraulic system (60) and a control valve (40), which is fluidly positioned between the implement hydraulic system (60) and the hydraulic coupler actuator (35). The control valve (40) can be moved by an electrical actuator (56) electrically connected to a switch (50) in an operator compartment (13). During tool changing, a coupler pin (33, 34) of the tool quick coupler assembly (30) is moved toward a decoupling position by simultaneously energizing the electrical actuator (56) while actuating the hydraulic bucket actuator (14) in order to create fluid pressure in the implement hydraulic system (60) which utilizes open center valves.

Description

TOOL QUICK COUPLER AND MACHINE USING SAME

Technical Field

The present disclosure relates generally to a tool quick coupler for a machine, and more particularly to utilizing a fluid connection to and from the implement hydraulic system of the machine to actuate a tool quick coupler.

Background Art

Wheel loaders designate a group of machines generally identified by a chassis supported by four wheels that carry hydraulically actuated boom and bucket actuators. Wheel loaders are known to come in a variety of sizes and shapes and may be steered using conventional wheel steering techniques or hydraulically via an articulated chassis. Although the tool most often associated with a wheel loader is a loader bucket, wheel loaders can be configured with a variety of different tools for specific applications including but not limited to ground engaging tools, forks, blades, rakes, brooms, material handling arms, snow removal plows and several others. In many instances, the wheel loader will be configured with a certain tool for performing a designated duty cycle which does not change. In other instances, there may be a desire to change the tool to being utilized by the wheel loader during or between duty cycles. For instance, a wheel loader may utilize a general purpose bucket for much of its duty cycle, but also utilize forks during a different part of a work day. In order to hasten changing tools on a wheel loader, hydraulically actuated quick couplers enable an operator to disengage the machine from one tool and couple the machine to a second tool, often without needing to leave the operator compartment. In one specific example, a Caterpillar 950H wheel loader may either manual pin actuation or utilize hydraulic fluid from a continuously pressurized reservoir associated with hydraulic wheel brake actuators for providing the necessary pressurized hydraulic fluid to operate the quick coupler. Unfortunately, not all wheel loaders have a readily available continuous supply of pressurized fluid available for operating a quick coupler. Changing tools on such machines can be a labor intensive and time consuming process.

The present disclosure is directed to one or more of the problems set forth above.

Summary of the Disclosure

In one aspect, a machine includes an implement hydraulic system with a hydraulic boom actuator and a hydraulic bucket actuator. A tool quick coupler assembly

l includes a hydraulic coupler actuator fluidly connected to the implement hydraulic system. A control valve is fluidly positioned between the implement hydraulic system and the hydraulic coupler actuator.

In another aspect, a method of operating a machine includes moving a coupler pin toward a decoupling position. Hydraulic fluid is supplied from an implement hydraulic system to a hydraulic coupler actuator. An electrical actuator coupled to a control valve is simultaneously energized while actuating a hydraulic implement actuator.

In still another aspect, a hydraulic system includes an open center boom control valve member and an open center bucket control valve member positioned in a valve housing. A first adapter, which defines a pump supply port and a coupler supply port, is attached over a pump port of the valve housing. A second adapter, which defines a tank return port and a coupler return port, is attached over a tank port of the valve housing.

Brief Description of the Drawings

Figure 1 is a general view of a machine according to one aspect of the present disclosure;

Figure 2 is an exemplary view of a tool quick coupler assembly according to another aspect of the present disclosure; and

Figure 3 is a schematic view of a hydraulic system circuitry for the machine of Figure 1.

Detailed Description

Referring to Figure 1 , a machine 10 is illustrated as a wheel loader, but may be any other suitable machine such as a telehandler, an excavator or any other of the numerous machines that utilize a hydraulic implement system and may utilize two or more different tools. Wheel loader 10 includes a chassis that is supported by four wheels in a conventional manner. The chassis carries a boom that may be raised and lowered via a hydraulic boom actuator 15, and also carries a tool 18, which may be extended and retracted via a hydraulic bucket actuator 14 in a conventional manner. Instead of tool 18 being attached directly to boom 12, an intervening quick coupler 30 interconnects boom 12 to tool 18, which is illustrated as a bucket. Bucket 18 may include a hook 19 that engages a bar 31 of tool coupler assembly 30. Those skilled in the art will recognize that an alternative strategy might have a bucket with a bar that is engaged by a hook of a tool quick coupler assembly without departing from the scope of this disclosure. The connection is completed by coupler pins (see infra) of the tool coupler assembly 30 being received in counterpart pin bores 20 of bucket 18. The coupling and decoupling procedure associated with coupler assembly 30 is accomplished in part via an electrical switch 50 located in an operator compartment 13.

Referring now in addition to Figure 2, tool quick coupler assembly 30 includes a base 32 that is securely attached to boom 12 using conventional techniques, such as fastener bolts and the like. Thus, extending and retracting hydraulic bucket actuator 14 causes tool coupler assembly 30 to extend and retract relative to boom 12 in a known manner. Tool quick coupler assembly 30 includes a pair of coupler pins 33 and 34 which may be moved into place and received in counterpart pin bores 20 of a tool to facilitate attachment of tool 18 to machine 10. Bar 31 may be positioned at any suitable location on tool quick coupler assembly 30. Coupler pins 33 and 34 move horizontally via the action of a hydraulic coupler actuator 35 via intervening mechanical links 38. Hydraulic coupler actuator 35 may be a double action hydraulic cylinder or two separate hydraulic cylinders. A control valve 40 may be mounted adjacent hydraulic coupler actuator 35 and provides the means by which hydraulic fluid from a hydraulic coupler supply line supply hose 36 causes hydraulic coupler actuator 35 to extend or retract. Low pressure hydraulic fluid from hydraulic coupler actuator 35 is returned via a coupler return hose 37.

Referring now in additional to Figure 3, the hydraulic system for the machine of Figure 1 includes an implement hydraulic system 60, a steering hydraulic system 90 and the hydraulics associated with the tool coupler assembly 30 shown in Figure 2. Implement hydraulic system 60 includes many features well known in the art including implement control valves 61 located in the operator compartment 13 in order to control the actuation of hydraulic boom actuator(s) 15 and hydraulic bucket actuator 14 via a valve block assembly 69. In particular, the control valve 61 operate pilot valves to deliver hydraulic fluid to opposite ends of open center boom control valve member 72 and open center bucket control valve member 73 to reposition the same in a valve housing 70, which is a portion of the valve block assembly 69. Thus, when implement controls 61 are not being actuated, the sequentially arranged valve members 73 and 72 are open center valve members that result in pump 63 circulating hydraulic fluid at relatively low pressure from tank 62, through valve block assembly 69, and back to tank 62 for recirculation. Hydraulic fluid is supplied from pump 63 via a pump hose 64 that is connected to a pump supply port 80 of an adapter 75 that is attached to valve housing 70. The term "hose" is intended to encompass any collection of conduits (flexible or rigid) and any fittings for transporting fluid from one location to another within a system. Adapter 75 may be attached over the pump port 74 of valve housing 70. Adapter 75 also includes a coupler supply port 79 that facilitates connection to coupler supply hose 36, which is also shown in Figure 2. Likewise, return fluid returns to tank 62 via a tank hose 65 that is connected to a tank return port 78 of an adapter 76, which is also attached to valve housing 70. Adapter 76 may be substantially identical to adapter 75 and includes a coupler return port 77 that facilitates connection to coupler return hose 37, which is also shown in Figure 2. Adapter 76 may be attached over tank port 71 of valve housing 70.

This implementation strategy of the tool coupler assembly allows for incorporation into the implement hydraulic system 60 without any substantial modification to the implement hydraulic system other than the addition of adapters 75 and 76. In other words, a machine without a tool quick coupler assembly 30 of the present disclosure would show pump hose 64 connected directly to pump port 70 of valve housing, and tank hose 65 connected directly to tank port 71 of valve housing 70. Thus, the necessary hydraulic connections for the tool quick coupler assembly 30 of the present disclosure can be accomplished simply by disconnecting the existing pump hose 64 and tank hose 65 from valve housing 70, attaching adapters 75 and 76 to valve housing 70, and then reattaching the pump hose 64 and tank hose 65 to the respective pump supply port 80 and tank return port 78 of the adapter 75 and 76. Coupler supply hose 36 is connected to coupler supply port 79, and coupler return hose 37 is connected to coupler return port 77. Nevertheless, those skilled in the art will appreciate that coupler supply hose 36 and coupler return hose 37 could be connected to implement hydraulic system 60 elsewhere, such as directly to the lines extending between hydraulic bucket actuator 14 and valve block assembly 69, without departing from the present disclosure.

In order to slow the action of hydraulic coupler actuator 35 during a de-coupling and coupling procedure, a flow restriction orifice 49 may be located in coupler supply hose 36 at an appropriate location, such as adjacent coupler supply port 79. Tool quick coupler assembly 30 includes a control valve 40 that is fluidly positioned between the implement hydraulic system 60 and the hydraulic coupler actuator 35. Control valve 40 may include an electrical actuator 56, such as a solenoid, and a control valve member 43 that is movable between a decoupling position as shown with electrical actuator 56 energized, and a coupling position when electrical actuator 56 is deenergized due to the biasing force of a spring 44. Control valve 40 may also include a pressure relief valve 46 if desired. The tool quick coupler assembly 30 may also include a pair of ball valves 45 that facilitate detachment of the subassembly shown in Figure 2, such as for servicing and the like. Electrical actuator 56 may be connected to the electrical switch 50 described earlier as located in the operator compartment 13 via a conventional communication line 54. The electrical switch 50 may include a toggle component 51 that includes an enablement feature 52 coupled to a lock 53. Enablement feature 52 may be moved to one side to retract lock 53 to enable the toggle 51 to move to a position that energizes electrical actuator 56. Thus, more than an accidentally bumping of electrical switch 50 may be necessary in order to energize electrical actuator 56 in order to prevent accidental movement of control valve member 43 during normal operation of machine 10.

Industrial Applicability

The present disclosure is applicable to any machine that includes an implement hydraulic system and is configured to be coupled to different tools for carrying out various operations as discussed earlier. Although the present disclosure finds particular application to wheel loaders, the present disclosure is not so limited as the same concepts may be applied to other machines including but not limited to telehandlers, excavators and other known machines. The present disclosure finds particular applicability to machines that include an implement hydraulic system with normally open center valve strategies and no other hydraulic pressure system, such as hydraulic brakes, that may be tapped and utilized for providing hydraulic fluid to operate a tool quick coupler assembly 30 according to the present disclosure.

With reference to Figures 1 -3, coupling machine 10 to a tool 18 is accomplished by the machine operator approaching the tool with the hydraulic boom actuator 15 nearly fully retracted and the hydraulic bucket actuator 14 slightly extended so that bar 31 is located at a horizontal position lower than a hook 19 of tool 18. When the machine contacts the tool, the hydraulic bucket actuator 14 is retracted causing the bar 31 of the tool quick coupler assembly 30 to engage hook 19 of tool 18. After the hook(s) 19 engages horizontal bar 31 , a combination of hydraulic bucket actuator retraction and maybe hydraulic boom actuator extension is performed until the base 32 of tool quick coupler assembly 30 contacts a backside of tool 18. In this position, coupler pins 33 and 34 should come into alignment with the receiving pin bores 20 if the coupler pins 33 and 34 are in their decoupling position as shown in Figure 2. The coupler pins 33 and 34 may be moved to their decoupling position by simultaneously actuating at least one hydraulic implement actuator 14 or 15 while energizing electrical actuator 56 via appropriate movement of switch 50. Energization of electrical actuator 56 moves control valve member 43 to the position shown in Figure 3, while retracting hydraulic bucket actuator 14 causes pressure to build in pump hose 64, which is fluidly connected to coupler supply hose 36 via adapter 75. If none of the implement actuators 14 or 15 are actuated, pressure in implement hydraulic system 60 remains low due to the normally open center valve configuration, and hence the tool coupler assembly 30 is without hydraulic power to move hydraulic coupler actuator 35 in either direction.

After the coupler pins 33 and 34 are brought into alignment with the pin bore(s) 20 of tool 18, the electrical switch 50 may be returned to a de-energized position causing spring 44 to move control valve member 43 to the right. When this is done, the coupler supply hose 36 causes fluid to extend hydraulic coupler actuator

35 to move coupler pins 33 and 34 into their respective pins bores 20 of tool 18 via the intervening action of mechanical linkage 38. The coupling of tool 18 to machine 10 is then complete, thus allowing the operator to perform operations with the tool 18 as desired.

A decoupling operation is performed by typically contracting the hydraulic boom actuator(s) 15 so that the tool 18 is located near the ground. Next, the hydraulic bucket actuator 14 may be slightly extended so that when the coupler pins are moved to a decoupling position, the tool 18 will swing on bar 31 via hook 19 to a position where coupler pins 33 and 34 are out of alignment with pin bore(s) 20 of tool 18, and a bottom edge of the tool 18 contacts the ground. While the hydraulic bucket actuator 14 is being extended, the operator will move enablement feature 52 to allow toggle component 51 to move to a position to energize electrical actuator 56 causing control valve member 43 to move to the position shown in Figure 3. This will cause hydraulic fluid to retract hydraulic coupler actuator 35 and disengage coupler pins 33 and 34 from the respective pin bores 20. As tool 18 comes to rest on the ground, the bucket tilt actuator 14 can continue to be extended so that bar 31 disengages from hook 19. The machine operator can then back the machine away from tool 18 and approach a different tool for coupling of a machine 10 as described earlier.

It should be understood that the above description is intended for illustrative purposes only, and is not intended to limit the scope of the present disclosure in any way. Thus, those skilled in the art will appreciate that other aspects of the disclosure can be obtained from a study of the drawings, the disclosure and the appended claims.

List of References: 10. Machine

11. Chassis

12. Boom

13. Operator Compartment 14. Hydraulic Bucket Actuator

15. Hydraulic Boom Actuator

18. Tool

19. Hook

20. Pin Bore 30. Tool Quick Coupler Assembly

31. Bar

32. Base

33. Coupler Pin

34. Coupler Pin 35. Hydraulic Coupler Actuator

36. Coupler Supply Hose

37. Coupler Return Hose

38. Mechanical Link 40. Control Valve 43. Control Valve Member

44. Biasing Spring

45. Ball Valves

49. Flow Restriction Orifice

50. Electrical Switch 51. Toggle Component

52. Enablement Feature

53. Lock

54. Communication Line 56. Electrical Actuator 60. Implement Hydraulic System

61. Implement Control Valves

62. Tank

63. Pump 64. Pump Hose

65. Tank Hose

69. Valve Block Assembly

70. Valve Housing 71. Tank Port

72. Open Center Boom Control Valve Member

73. Open Center Bucket Control Valve Member

74. Pump Port

75. Adapter 76. Adapter

77. Coupler Return Port

78. Tank Return Port

79. Coupler Supply Port

80. Pump Supply Port 90. Steering System

Claims

1. A machine comprises: an implement hydraulic system including a hydraulic boom actuator and a hydraulic bucket actuator; and a tool quick coupler assembly including a hydraulic coupler actuator fluidly connected to the implement hydraulic system, and a control valve fluidly positioned between the implement hydraulic system and the hydraulic coupler actuator.

2. The machine as claimed in claim 1 , wherein the tool quick coupler assembly includes an electrical actuator operably coupled to move the control valve from a coupling position to a decoupling position.

3. The machine as claimed in claim 2, wherein the electrical actuator is electrically connected to an electrical switch located in an operator compartment carried by a chassis; and the electrical switch includes an enablement feature movable between a first position at which the electrical switch is locked in a deactivated position, and an unlocked position at which the electrical switch is moveable to an activated position.

4. The machine as claimed in claim 3, wherein the implement hydraulic system includes a valve block assembly with a pump port and a tank return port; and the tool quick coupler includes a hydraulic supply line fluidly connected to the pump port, and a hydraulic return line fluidly connected to the tank return port.

5. The machine as claimed in claim 4, wherein the hydraulic supply line includes a supply hose connected to a first adaptor of the valve block assembly; and the hydraulic return line includes a return hose connected to a second adaptor of the valve block assembly.

6. The machine as claimed in claim 5, wherein the hydraulic supply line includes a flow restriction orifice for reducing an actuation rate of the hydraulic coupler actuator; and the control valve is biased toward the coupling position.

7. The machine as claimed in claim 6, wherein the implement hydraulic system includes a pump hose connected to the first adapter; and a tank return hose connected to the second adapter.

8. The machine as claimed in claim 7, wherein the machine is a wheel loader.

9. A method of operating a machine comprises: moving a coupler pin toward a decoupling position; supplying hydraulic fluid from an implement hydraulic system to a hydraulic coupler actuator; energizing simultaneously an electrical actuator coupled to a control valve: and actuating a hydraulic implement actuator.

10. The method as claimed in claim 9 further includes: positioning a coupler pin into alignment with a pin bore of a tool; moving the coupler pin from the decoupling position toward a coupling position into the pin bore of the tool; and de-energizing the electrical actuator.

11. The method as claimed in claim 10, wherein the energizing further includes moving an enablement feature of an electrical switch from a locked position to an unlocked position before hand, and moving the electrical switch from a de-energized position toward the energized position.

12. The method as claimed in claim 11 , wherein the positioning further includes contacting the machine with a tool by engaging a hook with a bar and retracting a hydraulic bucket actuator.

13. The method as claimed in claim 12, wherein the supplying further includes slowing a movement rate of the coupler pin by channeling the hydraulic fluid through a flow restriction orifice.

14. The method as claimed in claim 13, wherein the positioning further includes extending the hydraulic bucket actuator.

15. The method as claimed in claim 14, wherein the supplying further includes passing hydraulic fluid through an adapter of a valve block assembly toward the hydraulic coupler actuator.

16. A hydraulic system comprising: a valve housing; an open center boom control valve member positioned in the valve housing; an open center bucket control valve member positioned in the valve housing; a first adapter, which defines a pump supply port and a coupler supply port, attached over pump port of the valve housing; and a second adapter, which defines a tank return port and a coupler return port, attached over a tank port of the valve housing.

17. The hydraulic system as claimed in claim 16 further includes a pump hose connected to the pump supply port; a tank hose connected to the tank port; a coupler supply hose connected to the coupler supply port; and a coupler return hose connected to the coupler return port.

18. The hydraulic system as claimed in claim 17 further includes a flow restriction orifice fluidly positioned between the first adapter and a hydraulic coupler actuator.