Patent Application
20210229609
The present application relates generally to electrical systems. More particularly, the present application relates to electrical isolation for electrical components of work machines.
Paving machines are used to grind out, apply, spread and compact paving material relatively evenly over a desired surface. These machines are regularly used in the construction of roads, parking lots and other areas where a smooth durable surface is required for cars, trucks and other vehicles to travel. When a crew arrives at a paving machine and/or cold planer, the crew often starts the machine to warm up the cold planer, the paver, and a screed. While the machines are warming up, external components may be plugged in and/or swapped out for use during operation of the machine.
WO 2011135846 A1 discusses an electrical system for an asphalt finisher that includes a changeover switch for changing between primary power of the asphalt finisher and a secondary, external, power source.
In one example, a work machine includes a power source, a plurality of connectors, and an isolator circuit. The power source is configured to provide power to an electrical system of the work machine. The plurality of connectors are for electrically connecting external components to the work machine and are configured to receive power from the power source. The isolator circuit is connected between at least one of the plurality of connectors and the electrical system of the work machine to selectively terminate power to the at least one of the plurality of connectors while the power source is providing power to the electrical system of the work machine.
In another example, a method of electrical isolation for a work machine includes powering, via a power source, an electrical system of the work machine; controlling an isolator circuit to terminate power to at least one of a plurality of connectors from the electrical system of the work machine; changing a connected state of at least one component with respect to the at least one of the plurality of connectors; and controlling the isolator circuit to reconnect power to the at least one of the plurality of connectors from the electrical system.
In another example, an electrical system of a work machine includes a machine electrical system, a plurality of connectors, and an isolator circuit. The machine electrical system is connected to receive power from a power source of the work machine. The plurality of connectors are for electrically connecting and disconnecting detachable components to the work machine and are configured to receive power from the machine electrical system. The isolator circuit is connected between at least one of the plurality of connectors and the machine electrical system to selectively terminate power to the at least one of the plurality of connectors while the power source is providing power to the machine electrical system.
The paving machine 100A may be used to spread and compact paving material relatively evenly over a desired surface. The paving machine may include a hopper, for example, for receiving asphalt material from a truck and a conveyor system for transferring the asphalt rearwardly from the hopper for discharge onto a roadbed. Screw augers may be used to spread the asphalt transversely across the roadbed in front of a screed plate. The screed plate smooths and somewhat compacts the asphalt material to leave a roadbed of uniform depth and smoothness.
The machine power 106 may be generated using one or more power sources such as a prime mover of the paving machine 100A, one or more backup power sources, and/or one or more external power sources. For example, the paving machine 100A may include an internal combustion engine, such as a diesel engine, an electric motor powered by a battery pack, or another engine type. In an example, in internal combustion engine may include one or more attached generators configured to convert mechanical energy from the engine into electrical energy for use by the paver electrical systems. In other examples, the machine power 106 may be received from one more backup power sources including batteries, capacitors, external power sources, and the like in addition to, or in place of, the primary power source.
The tractor electrical system 108 may encompass the electrical wiring and/or other electrical components of the tractor 102 to distribute electrical power from the machine power 106 to the isolator circuit 110 and other machine electrical components. For example, the paving machine 100A may include one or more control systems that include controllers, processors, and/or other components that receive and use electrical power. In one example, a single wire or wire harness may be used to carry electrical power from the machine power 106 to the isolator circuit 110. In conventional paving systems, the tractor electrical system 108 distributes power from the machine power 106 directly to the plurality of connectors 112A-112D. The screed electrical system 116 may encompass the electrical wiring and/or other electrical components of the screed 104 to distribute electrical power received through the electrical connector 122.
In conventional paver machines, power is received by the connectors 112A-112D and 118A-118F any time the engine of the paving machine is running and the tractor electrical system 108 is receiving power. When a crew arrives at a paving machine, it is desirable to start the engine to warm up the paving machine and also warm up the screed. While the machine is warming up, the crew plugs in and/or unplugs the components 114A-114D from the connectors 112A-112D. In conventional systems, because the engine is running and the machine is warming up, power is being provided to the connectors 112A-112D and 118A-118F.
The components 114A-114D and 120A-120F may be sensors, controls, and the like. For example, the tractor components 114A-114D may include left and right auger height sensors, left and right conveyor height sensors, and the like. The components 120A-120F may include left and right material height sensors, left and right grade sensors, pendant controls, and the like. The components 114A-114D and 120A-120F may also include any other sensors, controls, or other electrical components capable of connecting to the tractor 102 and/or the screed 104 through the connectors 112A-112D and/or 118A-118F.
The connectors 112A-112D and 118A-118F may be configured in any way to provide electrical power to the components 114A-114D and 120A-120F. In an example, the connectors may be male- or female-type connectors, and may include any number of pins or other electrical connections including, for example, a power connection and a ground connection. When plugging components into the connectors 112A-112D and 118A-118F, if the power line is hot, arcing may occur, which can cause damage to the component, the connector, and/or blow fuses of the electrical system of the tractor 102 or screed 104.
The isolator circuit 110 is configured to disconnect and isolate the connectors 112A-112D and 118A-118F from the machine power 106. The isolator circuit 110 may include one or more isolator switches which may be mechanical, electrical, or electro-mechanical, in an example, a single isolator switch may be used to provide isolation for all connectors 112A-112D and 118A-118F. The isolator switch(es) may be manually operable such that an operator of the paving machine 100A may manually terminate power to the connectors 112A-112D and 118A-118F when connecting/disconnecting any of the components 114A-114D and/or 120A-120F and then manually reconnect power to the connectors 112-112D and 118A-118F. This way, the machine power 106 can remain on, allowing connection/disconnection of components 114A-114D and 120A-120F while the paving machine 100A is warming up. In other examples, the isolator circuit 110 may be controllable through one or more electronic control inputs. For example, an input/output (IO) device located on the paving machine 100A, such as at an operator control station, may receive input from an operator to control a state of a respective switch of the isolation circuit 110.
The isolator circuit 130 may be physically positioned on the tractor 102 and the isolator circuit 132 may be physically positioned on the screed 104, for example. This way, if an operator of the paving machine 100B wishes to only connect/disconnect one of the components 120A-120F, the operator can control the isolator circuit 132, which may be positioned on the screed 104, near the connectors 118A-118F, rather than needing to control an isolator circuit positioned physically on the tractor 102. While illustrated as connected between the screed electrical system 116 and the connectors 118A-118F, the isolator circuit 132 may also be connected between the electrical connector 122 and the screed electrical system 116, for example.
The paving machine 1000, as illustrated in
The machine power 202 may be generated using one or more power sources such as a prime mover of the cold planer machine 200, one or more backup power sources, and/or one or more external power sources. For example, the cold planer machine may include an internal combustion engine, such as a diesel engine, an electric motor powered by a battery pack, or another engine type. The planer electrical system 204 may encompass the electrical wiring and/or other electrical components of the cold planer machine 200 to distribute electrical power from the machine power 202 to the isolator circuit 206 and other machine electrical components. In one example, a single wire or wire harness may be used to carry electrical power from the machine power 202 to the isolator circuit 206.
In conventional cold planer machines, power is received by the connectors 208A-208F any time the engine is running and the planer electrical system 204 is receiving power. When a crew arrives at a cold planer machine, it is desirable to start the engine to warm up the cold planer machine. While the machine is warming up, the crew plugs in and/or unplugs the components 210A-210F from the connectors 208A-208F. in conventional systems, because the engine is running and the machine is warming up, power is being provided to the connectors 208A-208F.
The components 210A-210F may be sensors, controls, and the like. For example, the components 210A-210F may include grade sensors, pendant controls, and the like. The connectors 208A-208F may be configured in any way to provide electrical power to the components 210A-210F. In an example, the connectors may be male- or female-type connectors and may include any number of pins or other electrical connections including, for example, a power connection and a ground connection. When plugging components into the connectors 208A-208F, if the power line is hot, arcing may occur, which can cause damage to the component, the connector, and/or blow fuses of the electrical system of the cold planer machine 200.
The isolator circuit 206 is configured to disconnect and isolate the connectors 208A-208F from the machine power 202. The isolator circuit 206 may include one or more isolator switches which may be mechanical, electrical, or electro-mechanical. In an example, a single isolator switch may be used to provide isolation for all connectors 208A-208F, The isolator switch(es) may be manually operable such that an operator of the cold planer machine 200 may manually terminate power to the connectors 208A-208F when connecting/disconnecting any of the components 210A-210F and then manually reconnect power to the connectors 208A-208F. This way, the machine power 202 can remain on, allowing connection/disconnection of components 210A-210F while the cold planer machine 200 is warming up. In another example, several separate isolator switches may be connected between each connector 2084-208F and the planer electrical system 204.
At step 306, while power is terminated to the connectors, an operator of the work machine changes the connection state of at least one of the external components with respect to the connectors. This may include connecting a component to the work machine and/or disconnecting a component from the work machine. By changing the connection state while power is disconnected from the connectors, the risk of damage to the components and/or the work machine electrical system is reduced. At step 308, following connection or disconnection of the components, the isolator circuit is controlled to reconnect power to all connectors of the work machine from the machine electrical system.
At step 406, while power is terminated to the connectors of the tractor portion, an operator of the paving machine changes the connection state of at least one of the external components with respect to the tractor connectors. This may include connecting a component to the tractor and/or disconnecting a component from the tractor. By changing the connection state while power is disconnected from the connectors, the risk of damage to the components and/or the tractor electrical system is reduced. At step 408, following connection or disconnection of the components, the isolator circuit 130 is controlled to reconnect power to all connectors of the tractor portion from the tractor electrical system,
At step 410, an isolator circuit, such as the isolator circuit 132, is controlled to terminate power to electrical connectors of the screed portion of the paving machine that allow connection or disconnection of external components, such as external sensors, controls, and the like. At step 412, while power is terminated to the connectors of the screed portion, an operator of the paving machine changes the connection state of at least one of the external components with respect to the screed connectors. This may include connecting a component to the screed and/or disconnecting a component from the screed. By changing the connection state while power is disconnected from the connectors, the risk of damage to the components and/or the screed electrical system is reduced. At step 414, following connection or disconnection of the components, the isolator circuit 132 is controlled to reconnect power to all connectors of the screed portion from the screed electrical system.
In one illustrative example, a paving machine, such as a Caterpillar AP355F Paver, includes several external components that can be plugged into/unplugged from the paver and/or screed. For example, left and right auger height sensors and left and right conveyor height sensors can be plugged into the tractor of the paver. Left and right material height sensors, two grade sensors, and two pendant controls can be plugged into a screed connected to the paver. When a crew arrives at the paver, the crew may start the engine to warm up the paver and also warm up the screed heater. During this time, the crew plugs in and/or unplugs external devices as desired. Prior to performing these actions, one or more isolation circuits are controlled to terminate power from the paver electrical system to the connectors for the external devices. Once the power is terminated to the connectors, the external devices are plugged in or unplugged. Following connection/disconnection of the external devices, the isolation circuits are controlled to resupply power to the external components for use during operation of the paver.
The above detailed description is intended to be illustrative, and not restrictive. The scope of the disclosure should, therefore, be determined with references to the appended claims, along with the full scope of equivalents to which such claims are entitled.
