IP Library Granted Patent US 10,851,522
Granted Patent B2
US 10,851,522 · App. 16/092,234 · Granted Dec 1, 2020

Work vehicle

Inventors: Jumpei Kamiya (Akashi, JP); Hideyuki Tanaka (Akashi, JP)
Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
E02F9/2242E02F3/431E02F9/2246E02F9/2292F02D29/04F15B13/022F15B2211/20523F15B2211/20576F15B2211/4053F15B2211/7142
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Quick Facts
Patent No.
US 10,851,522
App. No.
16/092,234
Granted
Dec 1, 2020
Kind
B2
Abstract

The work vehicle includes: a working device; an auxiliary machine; and a priority valve that is switched between a normal position for directing pressure oil from an accessory pump toward the auxiliary machine and a merging position for directing the pressure oil from the accessory pump toward the working device. The work vehicle includes a control device that holds the priority valve in the normal position in case either the forward direction or the reverse direction which is indicated by a forward reverse operating device and a travel direction of the work vehicle do not match each other, and that switches the priority valve to the merging position in case either the forward direction or the reverse direction which is indicated by the forward reverse operating device and a travel direction of the work vehicle match each other and an operating device is in an operated state.

Claims (19)

1. A work vehicle, comprising:

a main pump and an accessory pump that are driven by an engine;

a working device that is driven by pressure oil discharged from the main pump;

an operating device that operates the working device;

an auxiliary machine that is driven by pressure oil discharged from the accessory pump;

a priority valve that is switched between a normal position and a merging position, the normal position directing the pressure oil discharged from the accessory pump toward the auxiliary machine, the merging position directing the pressure oil discharged from the accessory pump toward the working device;

a forward reverse operating device that that provides an indication of a forward direction and a reverse direction the work vehicle is desired to travel; and

a control device that holds the priority valve in the normal position in a first case when either the forward direction or the reverse direction which is indicated by the forward reverse operating device and a travel direction of the work vehicle do not match each other, and that switches the priority valve to the merging position in a second case when either the forward direction or the reverse direction which is indicated by the forward reverse operating device and the travel direction of the work vehicle match each other and the operating device is in an operated state.

2. The work vehicle according to claim 1 , further comprising

a transmission that makes switching between the forward direction and the reverse direction on the basis of the indication from the forward reverse operating device,

wherein the control device has: a forward/reverse determination section that determines whether or not a forward reverse switching operation is ongoing, and a travel direction estimation section that estimates the travel direction of the work vehicle, and

wherein, in the first case, the forward/reverse determination section determines that the forward reverse switching operation should start.

3. The work vehicle according to claim 2 , further comprising:

a vehicle speed detection device that detects a vehicle speed of the work vehicle,

wherein, in the second case, when the vehicle speed detected by the vehicle speed detection device is higher than a predetermined value, the forward/reverse determination section determines that the forward reverse switching operation is completed.

4. The work vehicle according to claim 2 ,

wherein, in the second case, when the indication indicated by the forward reverse operating device and the travel direction of the work vehicle match each other for at least a preset fixed time period the forward/reverse determination section determines that the forward reverse switching operation is completed.

5. The work vehicle according to claim 1 ,

wherein the control device holds the priority valve in the normal position until a preset fixed time period elapses after the working device starts to be operated by the operating device.

Assignments (2)
MERGER Recorded Oct 22, 2019
From: KCM CORPORATION
To: HITACHI CONSTRUCTION MACHINERY CO., LTD.
Reel/Frame 050787/0868 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 9, 2018
From: KAMIYA, JUMPEI; TANAKA, HIDEYUKI
To: KCM CORPORATION
Reel/Frame 047100/0810 →
Priority Claims (1)
JP 2016-160039 · Aug 17, 2016 · national
Continuity (1)
Related Publication 20200087892A1 · Mar 19, 2020