Coolant pump with integrated closed-loop control

Abstract

A coolant pump for an internal combustion engine (ICE) in a vehicle with a central engine control, having a pump shaft that drives an impeller for pumping a coolant. An axial piston pump operated via a wobble plate on a rear face of the impeller, conducts part of the pumped coolant away to a hydraulic circuit that extends from the axial piston pump via a proportional valve back to the pumped coolant and has a branch-off between the axial piston pump and the proportional valve as the hydraulic actuator. A regulating slide valve adjusts coolant volume flow of depending on pressure in the hydraulic circuit. A sensor detects a parameter characteristic of the coolant volume flow and outputs an actual value signal. A dedicated pump control controls the proportional valve based on the actual value signal of the sensor and a desired value signal of the central engine control.

1 . A coolant pump for pumping a coolant for an internal combustion engine in a vehicle comprising the internal combustion engine and a central engine control unit, said coolant pump comprising:
 a pump shaft which is rotatably mounted in a pump housing and which is driven by the internal combustion engine via a belt drive,   an impeller which is arranged on the pump shaft and accommodated in a pump chamber of the pump housing, pumping a coolant,   an axial piston pump which is actuated via a wobble plate on a rear side of the impeller and which branches-off a fraction of the pumped coolant,   a hydraulic circuit which extends from the axial piston pump via a proportional valve back to the pumped coolant and which includes a branch between the axial piston pump and the proportional valve as a hydraulic actuator,   a regulating slide valve which adjusts the volume flow of the coolant pumped by the coolant pump and which is slidable depending on a pressure in the hydraulic circuit,   a sensor which detects a parameter indicative of the volume flow of the pumped coolant and which outputs an actual value signal of the parameter, and   a dedicated pump control which controls the proportional valve in the hydraulic circuit on the basis of the actual value signal from the sensor and a target value signal from the central engine control unit.   
     
     
         2 . The coolant pump according to  claim 1 , wherein the pump control and the sensor are formed as a mutual electronic component. 
     
     
         3 . The coolant pump according to  claim 1 , wherein the sensor is a position sensor which detects the position of the regulating slide valve, and
 the desired value signal indicates i) a predetermined position of the regulating slide valve or ii) a predetermined volume flow and the speed of the internal combustion engine or coolant pump.   
     
     
         4 . The coolant pump according to  claim 1 , wherein the pump control limits a path of the regulating slide valve in an upper speed range of the pump. 
     
     
         5 . The coolant pump according to  claim 1 , wherein the pump control compares a relationship between the control duration of the proportional valve and a resulting position change of the regulating slide valve with a threshold value. 
     
     
         6 . The coolant pump according to  claim 1 , wherein the sensor is a pressure sensor which detects the pressure of the pumped volume flow of the coolant, and
 the desired value signal indicates i) a predetermined volume flow or ii) a pressure which is indicative of the volume flow of the pumped coolant.   
     
     
         7 . The coolant pump according to  claim 6 , wherein the pump control compares the pressure detected by the sensor with a threshold value. 
     
     
         8 . The coolant pump according to  claim 1 , wherein the pump control comprises a transceiver for receiving data from the central engine control unit and/or for sending data thereto, a microcomputer for performing a control procedure, a valve driver for driving the proportional valve, and a power supply distributor for supplying each component with electric power. 
     
     
         9 . The coolant pump according to  claim 2 , wherein the pump control has a housing of its own which is integrated into the single electronic component. 
     
     
         10 . The coolant pump according to  claim 2 , wherein the sensor has a housing of its own which is integrated into the single electronic component. 
     
     
         11 . The coolant pump according to  claim 1 , wherein the coolant to be pumped flows through a coolant inlet axially directed towards the impeller and is pumped by the impeller so as to leave the pump chamber via a radial coolant outlet. 
     
     
         12 . The coolant pump according to  claim 1 , wherein the coolant to be pumped flows through a coolant inlet axially directed towards the impeller and is pumped by the impeller so as to leave the pump chamber via an axial or semi-axial coolant outlet on the opposite side of the impeller. 
     
     
         13 . An electronic component for use in a mechanically driven coolant pump of a vehicle with an internal combustion engine and a central engine control unit, comprising a pump control and a sensor for detecting the position of a regulating slide valve in a pump chamber which limits the pumped volume flow or a sensor for detecting the pressure of the volume flow in the pump chamber. 
     
     
         14 . The electronic component according to  claim 13 , wherein a portion of the electronic component in which the pump control is accommodated and a portion of the electronic component in which the sensor is accommodated form an L-shaped arrangement with respect to one another. 
     
     
         15 . A method for controlling a mechanically driven coolant pump of a vehicle with an internal combustion engine and a central engine control unit, said method comprising the steps of:
 a1) calculating by way of the central engine control unit a desired value of a parameter, which is indicative of the volume flow of the pumped coolant, depending on operating parameters of the internal combustion engine; and   transmitting the desired value from the central engine control unit to a pump control of the coolant pump;   or   a2) transmitting operating parameters of the internal combustion engine from the central engine control unit to a pump control of the coolant pump; and   calculating by way of the pump control a desired value of a parameter, which is indicative of the volume flow of the pumped coolant, depending on the operating parameters of the internal combustion engine;   b) detecting an actual value of the parameter by a sensor;   c) transmitting the actual value from the sensor to the pump control; and   d) tuning by way of the pump control the position of a regulating slide valve, which limits the pumped volume flow of the coolant pump, depending on the desired value and the actual value by controlling a hydraulic actuator.   
     
     
         16 . (canceled) 
     
     
         17 . The control method according to  claim 15 , wherein the parameter which is indicative of the volume flow of the pumped coolant is a position of the regulating slide valve. 
     
     
         18 . The control method according to  claim 15 , wherein the parameter which is indicative of the volume flow of the pumped coolant is a pressure in a pump chamber of the coolant pump which corresponds to the volume flow of the pumped coolant.