Auxiliary hydraulic control system for a work machine

• US 6,062,331 A
• Filed: 10/09/1998
• Issued: 05/16/2000
• Est. Priority Date: 10/09/1998
• Status: Expired due to Term

• Current Assignee: Caterpillar Sarl (Caterpillar Incorporated)
• Original Assignee: SARL
• Inventors: Grunow, Timothy W., Schenck, Raymond T., Ufheil, Steven T.
• Primary Examiner(s): Rice, Kenneth R.
• Application Number:
  US09/169,499
• Time in Patent Office: 585 Days
• Field of Search: 180/268, 180/272, 180/273, 180/324
• US Class Current: 180/268
• CPC Class Codes: B60K 28/04 responsive to presence or absence of the driver, e.g. to weight or lack thereof
• CPC Class Codes: E02F 9/2025 Particular purposes of control systems not otherwise provided for E02F3/16, E02F3/26, sub-groups of E02F3/43, E02F3/651, sub-groups of E02F3/84, E02F3/907, E02F5/145 take precedence
• CPC Class Codes: E02F 9/2221 Control of flow rate; Load sensing arrangements E02F9/2203 take precedence over E02F9/2221
• CPC Class Codes: E02F 9/24 Safety devices , e.g. for preventing overload E02F9/226 takes precedence

Abstract

An auxiliary hydraulic control system for controlling the flow of hydraulic fluid within an auxiliary hydraulic circuit associated with a particular work machine wherein such system includes a first bi-directional proportional switch actuatable to control the direction of flow within the auxiliary hydraulic circuit in either a first or a second direction and at a flow rate which is proportional to the amount of pressure being exerted on the switch in the selected direction, a second switch actuatable to provide continuous flow in the selected direction and at the selected flow rate, and an electronic controller coupled to the first and second switches for receiving signals therefrom, the controller outputting a signal to initiate continuous flow in the selected direction and at the selected flow rate when the controller receives signals indicative of the first switch being actuated, the second switch being actuated, and the first switch being released within a predetermined period of time after the second switch has been actuated. An interlock override feature is also provided whereby, under certain operating conditions, the continuous flow function will be allowed to remain active while an operator exits the machine seat.

Claims

1. A control system for controlling the flow of hydraulic fluid within an auxiliary hydraulic circuit associated with a work machine wherein the work machine includes an implement system and an auxiliary hydraulic circuit for controlling the operation of certain attachments or tools which are mountable to the implement system, said auxiliary hydraulic control system comprising:

a first switch actuatable to control the direction of fluid flow within the auxiliary hydraulic circuit, said first switch being actuatable in a first manner to output a signal indicative of directing flow in a first direction within the auxiliary hydraulic circuit and said first switch being actuatable in a second manner to output a signal indicative of directing flow in a second direction within the auxiliary hydraulic circuit, said first switch outputting said signals for directing flow in one of said first and second directions for as long as said switch is held in its actuated position;

a second switch actuatable to output a signal indicative of providing continuous flow in one of said first and second directions within the auxiliary hydraulic circuit based upon the direction of flow selected by actuation of said first switch;

an electronic controller coupled to said first and second switches for receiving signals therefrom, said controller being operable to receive a signal corresponding to said first switch being actuated in one of said first and second manners, a signal corresponding to said second switch being actuated, and a signal corresponding to when said first switch has been released;

said controller outputting a signal to initiate continuous flow within the auxiliary hydraulic circuit in one of said first and second directions when said controller receives the signal corresponding to said first switch being actuated to direct flow in one of said first and second directions, the signal corresponding to said second switch being actuated to provide continuous flow in the selected direction, and the signal corresponding to said first switch being released within a predetermined period of time after said second switch has been actuated.

2. The control system, as set forth in claim 1, wherein said first switch is a bi-directional momentary switch.

3. The control system, as set forth in claim 1, wherein said predetermined period of time is one second.

4. The control system, as set forth in claim 1, wherein said controller outputs a signal to discontinue continuous flow in the selected direction within the auxiliary hydraulic circuit when said controller receives a signal corresponding to a subsequent actuation of said first switch.

5. The control system, as set forth in claim 1, wherein said controller outputs a signal to discontinue continuous flow in the selected direction within the auxiliary hydraulic circuit when said controller receives a signal corresponding to a subsequent actuation of said second switch.

6. The system, as set forth in claim 1, wherein said second switch is a momentary switch.

7. The control system, as set forth in claim 1, wherein said first switch is a bi-directional proportional switch having opposed sides, applying a force to one side of said proportional switch outputting a signal indicative of directing flow in a first direction within the auxiliary hydraulic circuit at a flow rate which is proportional to the amount of force exerted on the one side of said switch up to a maximum flow rate, and applying a force to the opposite side of said proportional switch outputting a signal indicative of directing flow in a second direction within the auxiliary hydraulic circuit at a flow rate which is proportional to the amount of force exerted on the opposite side of said switch up to a maximum flow rate.

8. The control system, as set forth in claim 7 above, wherein said second switch is actuatable to output a signal indicative of providing continuous flow in one of said first and second directions within the auxiliary hydraulic circuit at the same flow rate dictated by the actuated position of said first switch when said second switch is actuated.

9. The control system, as set forth in claim 1, wherein the work machine includes an operator restraint mechanism and an operator seat, said auxiliary hydraulic control system further including:

a third switch coupled to the operator restraint mechanism and actuatable between a first state corresponding to the condition when said operator restraint mechanism is in a non-restraining condition and a second state corresponding to the condition when said operator restraint mechanism is in a restraining condition;

a fourth switch coupled to the operator seat and actuatable between a first state corresponding to the condition when an operator is not present in the seat and a second state corresponding to the condition when an operator is present in the seat; and

a fifth switch actuatable to override certain signal inputs to said controller;

said controller coupled to said third, fourth and fifth switches for receiving signals therefrom, said controller being operable to receive a signal indicative of when said third switch is in its first or second state, a signal indicative of when said fourth switch is in its first or second state, and a signal indicative of when said fifth switch has been actuated;

said controller being capable of outputting a signal to discontinue continuous flow when said controller receives a signal indicative of said third switch being in its first state;

said controller being capable of outputting a signal to discontinue continuous flow when said controller receives a signal indicative of said fourth switch being in its first state;

said controller outputting a signal to continue continuous flow in the selected direction regardless of the signals received from said third and fourth switches when said controller receives a signal indicative of said fifth switch being actuated.

10. An auxiliary hydraulic control system for controlling the operation of an attachment or tool mounted to a work machine wherein the work machine includes an implement system, the attachment or tool being mountable to the implement system, and an auxiliary hydraulic circuit operable to provide hydraulic fluid flow to the attachment or tool, said auxiliary hydraulic system comprising:

a bi-directional proportional input device actuatable to control the direction of flow within the auxiliary hydraulic circuit, said input device being actuatable in one direction so as to generate a signal corresponding to directing fluid flow in a first direction at a flow rate which is proportional to the amount of pressure exerted on said input device in said one direction, said input device being actuatable in another direction so as to generate a signal corresponding to directing fluid flow in a second direction at a flow rate which is proportional to the amount of pressure exerted on said input device in said another direction;

a continuous flow switch actuatable to generate a signal to provide continuous flow in one of said first and second directions within the auxiliary hydraulic circuit at the selected flow rate based upon the direction of flow and the flow rate selected by actuation of said bi-directional input device;

and an electronic controller coupled to said bi-directional input device and to said continuous flow switch to receive signals therefrom, said controller being operable to receive a signal from said bi-directional input device indicative of said input device being actuated in one of said first and second directions at a particular flow rate depending upon the amount of pressure being exerted on said input device in the selected direction, a signal indicative of said continuous flow switch being actuated, and a signal indicative of when said bi-directional input device has been released;

said controller outputting a signal to initiate continuous flow within the auxiliary hydraulic circuit in one of said first and second directions and at the particular flow rate directed by said bi-directional input device at the time said continuous flow switch was actuated when said controller receives the signal indicative of said bi-directional proportional input device being actuated in one of said first and second directions at a particular flow rate, the signal indicative of said continuous flow switch being actuated to provide continuous flow in the selected direction at the selected flow rate, and the signal indicative of said bi-directional input device being released within a predetermined period of time after said continuous flow switch has/been actuated.

11. The auxiliary hydraulic control system, as set forth in claim 10, wherein said controller is operable to receive a signal indicative of said continuous flow switch being released prior to the release of said bi-directional input device before said controller will output a signal to initiate continuous flow in the selected direction.

12. The auxiliary hydraulic control system, as set forth in claim 10, wherein said controller outputs a signal to discontinue continuous flow in the selected direction within the auxiliary hydraulic circuit when said controller receives a signal indicative of a subsequent actuation of said bi-directional proportional input device.

13. The auxiliary hydraulic control system, as set forth in claim 10, wherein said controller outputs a signal to discontinue continuous flow in the selected direction within the auxiliary hydraulic circuit when said controller receives a signal indicative of a subsequent actuation of said continuous flow switch.

14. The auxiliary hydraulic control system, as set forth in claim 10, wherein the work machine includes an implement joystick for controlling the operation of the implement system, said bi-directional proportional input device being located on said joystick.

15. The auxiliary hydraulic control system, as set forth in claim 14, wherein the continuous flow switch is located on said joystick.

16. The auxiliary hydraulic control system, as set forth in claim 10, wherein the work machine includes an operator restraint mechanism and an operator seat, said auxiliary hydraulic control system further including:

a third switch coupled to the operator restraint mechanism and actuatable to output a signal indicative of when said operator restraint mechanism is not in a restraining condition;

a fourth switch coupled to the operator seat and actuatable to output a signal indicative of when an operator is not present in the operator seat;

a fifth switch actuatable to output a signal to override certain signal inputs to said controller;

said controller coupled to said third, fourth and fifth switches for receiving signals therefrom;

said controller being capable of outputting a signal to discontinue continuous flow when said controller receives a signal indicative of when said operator restraint mechanism is not in a restraining condition;

said controller being capable of outputting a signal to discontinue continuous flow when said controller receives a signal indicative of when an operator is not present in the operator seat;

said controller outputting a signal to continue continuous flow in the selected direction and at the selected flow rate regardless of any signals received from said third and fourth switches when said controller receives a signal indicative of said fifth switch being actuated.

17. The auxiliary hydraulic control system, as set forth in claim 16, wherein said third switch is actuatable to output a signal indicative of when said operator restraint mechanism is in a restraining condition, and said fourth switch is actuatable to output a signal indicative of when an operator is present in the seat, said controller being operable to output a signal to continue continuous flow in the selected direction and at the selected flow rate when said controller receives a signal indicative of said fifth switch being actuated at a time when said third switch is outputting a signal indicative of said operator restraint mechanism being in its restraining condition and at a time when said fourth switch is outputting a signal indicative of an operator being present in the seat.

18. An auxiliary hydraulic control system for controlling the flow of hydraulic fluid within an auxiliary hydraulic circuit associated with a work machine, the auxiliary hydraulic circuit controlling the operation of certain tools which are attachable to the work machine, said auxiliary hydraulic control system comprising:

an electronic controller coupled to a first switch and a second switch to receive signals therefrom,

said first switch being a bi-directional proportional momentary switch actuatable to control the direction of flow within the auxiliary hydraulic circuit, said proportional switch being actuatable in one direction to generate a signal indicative of directing fluid flow in a first direction at a flow rate which is proportional to the amount of force being exerted on said switch in said one direction up to a maximum flow rate, said proportional switch being actuatable in another direction to generate a signal indicative of directing fluid flow in a second direction at a flow rate which is proportional to the amount of force being exerted on said switch in said another direction up to a maximum flow rate, said first switch generating said signals for as long as said first switch is held in its actuated position;

said second switch being a momentary switch actuatable to generate a signal to provide continuous flow in one of said first and second directions within the auxiliary hydraulic circuit at the selected flow rate directed by actuation of said first switch;

a first solenoid coupled to said controller for controlling the direction of flow within the auxiliary hydraulic circuit in said first direction;

a second solenoid coupled to said controller for controlling the direction of flow within the auxiliary hydraulic circuit in said second direction;

said controller being operable to receive a signal from said first switch indicative of said first switch being actuated in one of said first and second directions at a selected flow rate depending upon the amount of force being exerted on said first switch in the selected direction, a signal indicative of said second switch being actuated and released, and a signal indicative of when said first switch has been released;

said controller outputting a signal to one of said first and second solenoids to initiate continuous flow in one of said first and second directions and at the selected flow rate directed by said first switch at the time said second switch was actuated when said controller receives the signal indicative of said first switch being actuated in one of said first and second directions, the signal indicative of said second switch being actuated and released, and the signal indicative of said first switch being released within a predetermined period of time after said second switch has been actuated and released.

19. The auxiliary hydraulic control system, as set forth in claim 18, wherein said controller outputs a signal to one of said first and second solenoids to discontinue continuous flow in the selected direction when said controller receives a signal indicative of a subsequent actuation of said first switch.

20. The auxiliary hydraulic control system, as set forth in claim 18, wherein said controller outputs a signal to one of said first and second solenoids to discontinue continuous flow in the selected direction when said controller receives a signal indicative of a subsequent actuation of said second switch.

21. The auxiliary hydraulic control system, as set forth in claim 18, wherein the work machine includes an operator restraint mechanism and an operator seat, said auxiliary hydraulic control system further including:

a third switch coupled to the operator restraint mechanism and actuatable between a first state corresponding to the condition when said operator restraint mechanism is in a non-restraining condition and a second state corresponding to the condition when said operator restraint mechanism is in a restraining condition;

a fourth switch coupled to the operator seat and actuatable between a first state corresponding to the condition when an operator is not present in the seat and a second state corresponding to the condition when an operator is present in the seat; and

a fifth switch actuatable to override certain signal inputs to said controller;

said controller coupled to said third, fourth and fifth switches for receiving signals therefrom, said controller being operable to receive a signal indicative of when said third switch is either in or out of its first state, a signal indicative of when said third and fourth switches are either concurrently in their second states or at least one of said third and fourth switches is out of its second state, and a signal indicative of when said fifth switch has been actuated;

said controller being capable of outputting a signal to one of said first and second solenoids to discontinue continuous flow when said controller receives a signal indicative of when said third switch is in its first state;

said controller being capable of outputting a signal to one of said first and second solenoids to discontinue continuous flow when said controller receives a signal indicative of at least one of said third and fourth switches being out of its second state;

said controller continuing to output a signal to one of said first and second solenoids to continue continuous flow in the selected direction and at the selected flow rate regardless of any signals received from said third and fourth switches when said controller receives a signal indicative of said fifth switch being actuated concurrent with said controller receiving a signal indicative of said third switch being out of its first state and a signal indicative of said third and fourth switches being concurrently in their second state.