Pilot Circuit for Working Vehicle

• US 20160146227A1
• Filed: 07/10/2014
• Published: 05/26/2016
• Est. Priority Date: 07/12/2013
• Status: Abandoned Application

• Current Assignee: Caterpillar Sarl (Caterpillar Incorporated)
• Original Assignee: Caterpillar Sarl (Caterpillar Incorporated)
• Inventors: Hoshaku, Shota
• Application Number:
  US14/903,250
• Publication Number:
  US 20160146227A1
• Time in Patent Office: Days
• CPC Class Codes: B62D 1/22 Alternative steering-control elements, e.g. for teaching purposes
• CPC Class Codes: B62D 11/001 control systems B62D11/183 takes precedence
• CPC Class Codes: B62D 11/04 by means of separate power sources
• CPC Class Codes: E02D 17/13 Foundation slots or slits; Implements for making these slots or slits
• CPC Class Codes: E02F 9/2004 Control mechanisms, e.g. control levers control levers per se G05G
• CPC Class Codes: E02F 9/2253 Controlling the travelling speed of vehicles, e.g. adjusting travelling speed according to implement loads, control of hydrostatic transmission
• CPC Class Codes: E02F 9/2285 Pilot-operated systems
• CPC Class Codes: F15B 13/044 operated by electrically-controlled means, e.g. solenoids, torque-motors
• CPC Class Codes: F15B 15/149 Fluid interconnections, e.g. fluid connectors, passages
• CPC Class Codes: F15B 2211/20576 with multiple pumps
• CPC Class Codes: F15B 2211/30595 with additional valves between the groups of valves for multiple output members
• CPC Class Codes: F15B 2211/327 electrically or electronically
• CPC Class Codes: F15B 2211/329 actuated by fluid pressure
• CPC Class Codes: F15B 2211/45 Control of bleed-off flow, e.g. control of bypass flow to the return line
• CPC Class Codes: F15B 2211/6346 representing a state of input means, e.g. joystick position
• CPC Class Codes: F15B 2211/6658 Control using different modes, e.g. four-quadrant-operation, working mode and transportation mode
• CPC Class Codes: F15B 2211/67 Methods for controlling pilot pressure
• CPC Class Codes: F15B 2211/7135 Combinations of output members of different types, e.g. single-acting cylinders with rotary motors
• CPC Class Codes: F15B 2211/7142 the output members being arranged in multiple groups
• CPC Class Codes: F16H 61/4061 Control related to directional control valves, e.g. change-over valves, for crossing the feeding conduits
• CPC Class Codes: F16H 61/421 : Motor capacity control by electro-hydraulic control means, e.g. using solenoid valves

Abstract

The machine includes an operation selection switch to choose either an oil-pressured pilot operation or an electric operation, a control device to input an electric signal for traveling transmitted from an electric operation device and a selection signal from the operation selection switch. A third electro-magnetic valve may forbid outputting pilot pressure from a pilot valve, a first to fourth electro-magnetic proportional valve outputting a pilot pressure to the control valve for traveling based on the control signal from the control device and a first to fourth shuttle valve leading the output pilot pressure to the control valve for traveling.

Claims

1. A working vehicle comprising:

a hydraulic motor that drives a traveling apparatus;

a control valve for traveling of a hydraulic pilot type that performs oil supply and discharge control for the hydraulic motor;

a hydraulic pilot operation tool that actuates a pilot valve that outputs a pilot pressure to the control valve;

an electric operation device that outputs an electric signal;

operation selecting means for selecting hydraulic pilot operation or electric operation;

a control apparatus that receives the electric signal from the electric operation device, and a selection signal from the operation selecting means, and outputs a control signal;

an electromagnetic valve for prohibiting pilot pressure from the pilot valve from reaching the control valve for traveling on the basis of the control signal;

an electromagnetic proportional valve that outputs pilot pressure to the control valve for traveling on the basis of the control signal from the control apparatus; and

a shuttle valve that directs one of the pilot pressure output from the pilot valve or the electromagnetic proportional valve to the control valve for traveling.

2. The working vehicle according to claim 1, further comprising:

a hydraulic actuator for work;

a control valve for work of a hydraulic pilot type that performs oil supply and discharge control for the hydraulic actuator for work;

a pilot valve for work that outputs pilot pressure to the control valve for work; and

a joystick-type operation lever, wherein

the joystick-type operation lever has a function of a hydraulic pilot operation tool for work that actuates the pilot valve for work on the basis of lever operation, and a function of electric operation device for traveling that outputs the electric signal for traveling to the control apparatus on the basis of lever operation, and,

the working vehicle is provided with an electromagnetic valve for prohibiting pilot operation for work that prohibits an output of the pilot pressure from the pilot valve for work to the control valve for work on the basis of the control signal from the control apparatus.

3. The working vehicle according to claim 1, wherein the operation selecting means is provided in the electric operation device for traveling.

4. The working vehicle according to claim 1, wherein the electric operation device for traveling is also used as the operation selecting means by using, as the selection signal, the electric signal for traveling output from the electric operation device for traveling.

5. The working vehicle according to claim 2, wherein the operation selecting means is provided in the electric operation device for traveling.

6. The working vehicle according to claim 2, wherein the electric operation device for traveling is also used as the operation selecting means by using, as the selection signal, the electric signal for traveling output from the electric operation device for traveling.