JP2010501779A - Variable force solenoid with integrated position sensor - Google Patents

Abstract

  A phaser for an engine having at least one camshaft, comprising a housing, a rotor, a control valve, an actuator and a pulse wheel. The rotor is coupled to a camshaft that is coaxially disposed within the housing. The housing and the rotor define at least one vane that separates the chambers within the housing. The vane is rotatable to shift the relative angular position of the housing and the rotor. The control valve is housed by the rotor and directs fluid to the chamber of the phaser. The actuator positions the control valve and has at least one integrated position sensor so that the electrical connection of the actuator and the integrated position sensor is made by one connection, reducing fluid leakage from the phaser. The pulse wheel is attached to the phaser for rotation with the phaser and is aligned with the integral position sensor of the actuator.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a US Provisional Patent Application No. 60 / 823,529 filed Aug. 25, 2006, entitled “Variable Force Solenoid With Integrated Position Sensor”. Claims the invention disclosed in the specification. This application claims the benefit of US provisional patent application under Section 119 (e) of the provisional patent application, the above-mentioned application is hereby incorporated by reference.

  The present invention relates to the field of variable force solenoids. In particular, the present invention relates to a position sensor integrated variable force solenoid.

  In modern engines, a variable cam timing phaser is attached to one or more cams of the engine. These phasers can be used to change the timing of the valve or change the duration of the valve depending on the cam and lifter configuration. One method of adjusting the position of the phaser uses a centrally mounted spool controlled by a variable force solenoid (VFS) and has a separate position sensor that provides feedback to the electronic controller to adjust its position. That's it. Thus, a 4-cam engine has four connectors for each of the sensors associated with the four connectors for the variable force solenoid, resulting in eight locations for oil to leak from the engine.

  Therefore, there is a need to reduce leakage from the engine caused by the separate connection of the position sensor and variable force solenoid.

  A variable cam timing phaser for an internal combustion engine having at least one camshaft comprising a housing, a rotor, a control valve, an actuator and a pulse wheel. The housing has an outer periphery that receives the driving force. The rotor is coupled to a camshaft that is coaxially disposed within the housing. The housing and the rotor define at least one vane that separates the chambers within the housing. The vane is rotatable to shift the relative angular position of the housing and the rotor. The control valve is housed by the rotor and directs fluid to the chamber of the phaser. The actuator positions the control valve and has at least one integrated position sensor so that the electrical connection of the actuator and the integrated position sensor is made by one connection, reducing fluid leakage from the phaser. The pulse wheel is attached to the phaser for rotation with the phaser and is aligned with the integral position sensor of the actuator.

  In one embodiment, the pulse wheel is magnetic and the integrated position sensor detects the change in magnetic flux as the edge of the pulse wheel passes the sensor.

  In an alternative embodiment, the pulse wheel is iron and the integrated position sensor includes a magnet. The integrated position sensor detects changes in the magnetic field as the edge of the pulse wheel passes through the sensor.

FIG. 5 shows a side view of a variable cam timing phaser operated by a position sensor integrated variable force solenoid. The front view of a variable cam timing phaser is shown. FIG. 3 shows a front view of a variable force solenoid including a connector and an integrated position sensor. Figure 3 shows an alternative embodiment.

  Internal combustion engines have employed various mechanisms that change the angle between the camshaft and the crankshaft to improve engine performance or reduce exhaust gases. Most of these variable camshaft timing (VCT) mechanisms use one or more “vane phasers” on the engine camshaft 26 (or multiple camshafts in the case of multiple camshaft engines). In most cases, the phaser has a rotor 6 with one or more vanes, which is attached to the end of the camshaft 26 and has a vane chamber in which the vanes are fitted. Besieged by. It is likewise possible to attach the vane to the housing 2 and to arrange the chamber in the rotor 6. The outer periphery of the housing receives a driving force from a crankshaft, usually via a chain, belt or gear, or possibly from another camshaft in the case of a multi-cam engine, sprocket 4, pulley or gear. Is forming.

  The rotor 6 has a hole 6 a for accommodating the control valve 8. The control valve 8 directs the fluid flow to shift the relative angular position of the rotor 6 with respect to the housing 2. The position of the control valve 8 is influenced by the actuator 12 at one end and by a spring (not shown) at the other end. The actuator 12 as shown in FIG. 1 is a variable force solenoid, but other actuators such as a position sensor integrated stepper motor assembly or any linearly moving actuator may be used.

  In the prior art phaser, as mentioned in the background, a plurality of separate position sensors provide feedback to the electronic controller regarding the position of the camshaft relative to the crankshaft and the position of the phaser. The feedback is then sent from the electronic controller to the variable force solenoid, which affects the position of the control valve and phaser. Prior art phaser multiple position sensors require multiple connectors and connections between the position sensor, electronic controller and variable force solenoid.

  To reduce leakage that occurs in prior art systems, the phaser position sensor 14 of the present invention is incorporated into a variable force solenoid (VFS) 12, thereby providing electrical connection to the solenoid 12 and position sensor 14. Is made via the connector 16. Because of the magnetic flux and magnetic path associated with the variable force solenoid 12, the position sensor 16 must be isolated from such magnetic path in the VFS 12 as shown in FIGS.

  The position sensor 14 may be a Hall sensor, a magnetoresistive sensor, a variable reluctance sensor, or any other sensor that can detect a pulse wheel. However, throughout testing, Hall sensors and magnetoresistive sensors function better than variable reluctance sensors. Although only one position sensor is shown, there may be multiple sensors, which may sense the position of the housing or monitor other parts of the phaser.

  In one embodiment, a magnetic pulse wheel 10 may be used, as shown in FIGS. The pulse wheel 10 is attached to the camshaft and rotates with the phaser. The pulse wheel is arranged such that its edge 10 a is aligned with a position sensor 14 incorporated in the variable force solenoid 12. As the pulse wheel edge 10a passes the sensor 14, the sensor can detect the change in magnetic flux and thus the position of the camshaft.

  In another embodiment, the pulse wheel 10 may be iron and the position sensor 14 may include a magnet so that the position sensor can detect a change in magnetic field as the iron pulse wheel passes. .

  Alternatively, a rubber ring 30 may be used instead of the pulse wheel. The rubber ring 30 is attached to the camshaft and rotates together with the phaser. As shown in FIG. 4, magnets 32 are scattered along the circumference of the rubber 34 at intervals in the rubber ring, so that when the magnet 32 passes the position sensor 14, the sensor 14 It is possible to detect a change in the magnetic field when the magnet 32 of the ring rotates.

  Accordingly, it is to be understood that the embodiments of the present invention described herein are merely illustrative of the application of the principles of the present invention. References to details of the illustrated embodiments herein are not intended to limit the scope of the claims, and the claims themselves list the features that are considered essential to the invention. Is.

Claims (7)

A variable cam timing phaser for an internal combustion engine having at least one camshaft, comprising:
A housing having an outer periphery for receiving a driving force;
A rotor coupled to a camshaft coaxially disposed within the housing, wherein the housing and the rotor define at least one vane that separates a chamber within the housing, the vane comprising the housing and the rotor A rotor that is rotatable to shift the relative angular position of
A control valve housed by the rotor to direct fluid to the chamber;
An actuator for positioning the control valve having at least one integrated position sensor, whereby an electrical connection of the actuator and the integrated position sensor is made by one connection, and fluid leakage from the phaser Reduce the actuator,
A variable cam timing phaser comprising:   The variable cam timing phaser of claim 1, further comprising a pulse wheel attached to the phaser for rotation with the phaser and aligned with the integral position sensor of the actuator.   The variable cam timing of claim 2, wherein the pulse wheel is magnetic and the sensor detects a change in magnetic flux and determines the position of the camshaft when the pulse wheel passes through the integrated position sensor. Phaser.   The pulse wheel is iron, the integrated position sensor includes a magnet, and when the pulse wheel passes the integrated position sensor, the sensor detects a change in magnetic field and determines the position of the camshaft; The variable cam timing phaser of claim 2.   The variable cam timing phaser of claim 1, wherein the integrated position sensor is a Hall sensor, a magnetoresistive sensor or a variable reluctance sensor.   The variable cam timing phaser of claim 1, further comprising a rubber ring attached to the camshaft of the phaser for rotation with the phaser and interspersed with magnets spaced apart along an outer periphery. .   The integrated position sensor includes a magnet, and when the magnet of the rubber ring passes the integrated position sensor, the sensor detects a change in magnetic field and determines the position of the phase shifter. The variable cam timing phaser as described.

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