Overpressure prevention system for an agricultural machine

Patent metadata

Field	Value
Publication number	US-10823285-B2
Application number	US-201715481796-A
Country	US
Kind code	B2
Filing date	Apr 7, 2017
Priority date	Apr 7, 2017
Publication date	Nov 3, 2020
Grant date	Nov 3, 2020

Abstract

Agricultural machines such as sprayers can be improved by providing a pressure relief system in the operator cab to allow the operator cab to be pressurized while avoiding over-pressurization. The pressure relief system can be arranged to allow air to freely escape from the operator cab during what would otherwise be an over-pressurization event, such as a door or window being closed. In one aspect, the pressure relief system can include a spring-loaded pressure relief valve configured to passively allow air to escape from the cab in order to maintain a cab pressure at or below a predetermined threshold, such as 100 Pascals. In addition, interior and exterior pressures can be monitored for implementing a closed loop control for the pressurization system to enable a more comfortable experience for the operator.

First claim

We claim:

1. An agricultural sprayer comprising:
a chassis supported by a plurality of wheels, the chassis supporting an engine, a drive system, a lift arm assembly and an operator cab having a door or window;
a sprayer boom connected to the lift arm assembly;
an airflow system configured to draw ambient air into the operator cab to cause pressurization of the operator cab;
a pressure relief system arranged in the operator cab, the pressure relief system comprising a pressure relief valve actuated by a spring, wherein the pressure relief system is configured to release pressure from the operator cab when the pressurization of the operator cab exceeds a threshold;
a first pressure sensor configured to sense a first pressure in the operator cab;
a second pressure sensor configured to sense a second pressure external to the operator cab;
a cab sensor configured to sense an open or closed state of the door or window; and
a controller in communication with the airflow system, the first and second pressure sensors and the cab sensor, the controller executing a program stored in a non-transient medium operable to:
(a) determine a pressure differential by calculating a difference between the first and second pressures, wherein the pressure differential is positive when the first pressure is greater than the second pressure;
(b) activate the airflow system to provide a positive pressure differential when the cab sensor indicates the door or window is in the closed state; and
(c) deactivate the airflow system when the cab sensor indicates the door or window is in the open state.

2. The agricultural sprayer of claim 1 , wherein the pressure relief system releases pressure external to the operator cab to cause a decrease in the pressurization of the operator cab, and wherein the threshold is at least 100 Pascals.

3. The agricultural sprayer of claim 1 , wherein the controller activates the airflow system until a minimum positive pressure differential is achieved and then deactivates the airflow system.

Assignees

• Cnh Ind America Llc

Inventors

• Winkel Steven N
• Brooks Nathan

Classifications

• B60H1/00378 Primary

  for tractor or load vehicle cabins · CPC title

• B60H1/248

  Air-extractors, air-evacuation from the vehicle interior · CPC title

• F16H61/4157 Primary

  Control of braking, e.g. preventing pump over-speeding when motor acts as a pump · CPC title