Position control system

• US 4,310,172 A
• Filed: 04/23/1979
• Issued: 01/12/1982
• Est. Priority Date: 04/23/1979
• Status: Expired due to Term

• Current Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Claude, George T., Burns, Jerry W.
• Primary Examiner(s): Peters, Jr., Joseph F.
• Assistant Examiner(s): Weaver, Ross
• Application Number:
  US06/032,698
• Time in Patent Office: 995 Days
• Field of Search: 280/707, 280/703, 280/711, 280/702, 280/DIG. 1, 91/390, 60/390
• US Class Current: 280/6.158
• CPC Class Codes: B60G 17/01933 Velocity, e.g. relative velocity-displacement sensors
• CPC Class Codes: B60G 2204/111 on pneumatic springs
• CPC Class Codes: B60G 2400/252 vertical

Abstract

A height sensor is provided in a vehicle leveling system having an air spring including a pressurized chamber connected between sprung and unsprung vehicle masses. In one embodiment magnets located on a pair of followers within the chamber and attached for movement with the unsprung mass produce magnetic fields which pass through the wall of the chamber. A pair of detectors outside the chamber and mounted on the sprung mass for movement therewith detects the magnetic fields and thereby the movement of the followers to determine the relative spacing of the sprung and unsprung masses. In a second embodiment the magnetic devices and detectors are outside of the chamber with a follower internal of the chamber adapted to interrupt the magnetic field therebetween to determine the relative spacing of the sprung and unsprung masses.

Claims

1. A control system for adjusting the relative position of two members relatively movable with respect to one another comprising motor means operatively disposed between and interconnecting said members for movement toward and away from one another, follower means having telescoping parts mounted internally of said motor means and operatively connected to one of said members and movable therewith relative to the other of said members, spring means for yieldably holding said telescoping parts in an extending position, said parts of said follower means being telescoped together against the force of said spring in response to the predetermined movement of said members toward one another, Hall effect device means supported by the other of said members externally and at one end of said motor means for sensing the position of said follower means, an electrically energized control circuit, said Hall effect device means being responsive to the position of said follower means and operatively connected to said control circuit for triggering said circuit to produce pre-determined electrical signals, energizable activator means operatively connected to said control circuit and responsive to said predetermined electrical signals for activating said motor means for moving said members away from one another in response to the positioning of said follower means at a first position with respect to said Hall effect device means and to further effect movement of said members toward one another in response to the positioning of said follower means at a second position with respect to said Hall effect device means, and said first and second positions being at a pre-determined distance from one another to define a zone in which said motor means is free of activation by said circuit and said activator means.

2. A control system for adjusting the relative position of two members relatively movable with respect to one another comprising motor means formed by a pneumatic spring operatively disposed between and interconnecting said members for movement toward and away from one another, follower means mounted internally of said pneumatic spring and operatively connected to one of said members and movable therewith relative to the other of said members, said follower means having first and second telescoping parts and spring means for biasing said parts in an outward position, Hall effect device means supported by the other of said members and at one end of and externally of said pneumatic spring for sensing the position of said follower means, an electrically energized control circuit, said Hall effect device means being responsive to the position of said follower means and operatively connected to said control circuit for triggering said circuit to produce pre-determined electrical signals, electrically energizable compressor means operatively connected to said control circuit and responsive to said pre-determined electrical signals for supplying pressurized gas to said pneumatic spring for linearly elongating said spring for moving said members away from one another in response to the positioning of said follower means at a first position with respect to said Hall effect device means, electrically controlled exhaust valve means operatively connected to said control circuit for exhausting air from said pneumatic spring to permit said members to relatively move toward one another in response to the positioning of said follower means at a second position with respect to said Hall effect device means, said first and second positions being at a pre-determined distance from one another to define a deflection zone for said pneumatic spring in which said compressor means is inactive and said exhaust valve means is closed.

3. In an automatic leveling system for a vehicle having sprung and unsprung masses, an air spring comprising a column of gas confined within a cylindrical sleeve of resilient polymeric material interconnecting said sprung and unsprung masses, a double acting shock absorber operatively disposed within said sleeve interconnected between said sprung and unsprung masses for damping the oscillatory action of said air spring, electrically driven compressor means for supplying gas to said sleeve to increase the height of said column of gas confined therein to thereby increase the suspension spring spacing between said sprung and unsprung masses, electrically controlled exhaust valve means for exhausting pressurized gas from said sleeve to decrease the height of said column of gas to thereby decrease the suspension spring spacing between said sprung and unsprung masses, first and second magnetic means longitudinally spaced from one another within said column providing magnetic fields which extend externally of said air spring follower means mounting said magnetic means for movement in a predetermined path within the limits of said gas column, connector means operatively connecting said follower means to one of said masses so that said follower means and said magnetic means move in said path distances proportional to the relative movement of said masses, Hall effect device means externally and at one end of said air spring means for sensing movement of said magnetic means and triggering said compressor means and said exhaust valve means to effect supply of pressurized gas to said chamber when said masses are disposed at pre-determined minimal distances from another and exhaust pressurized gas from said chamber when said masses are disposed at a pre-determined maximum distance from one another, said Hall effect device means having a null zone permitting limited relative movement between said minimal and maximum distances without triggering operation of said compressor means and said exhaust valve means.

4. In an automatic leveling system for a vehicle having sprung and unsprung masses, an air spring comprising a column of gas confined within a rolling lobe cylindrical sleeve of resilient polymeric material interconnecting said sprung and unsprung masses, a double acting shock absorber operatively disposed within said sleeve interconnected between said sprung and unsprung masses for damping the oscillatory action of said air sprung, electrically driven compressor means for supplying gas to said sleeve to increase the height of said column of gas confined therein to thereby increase the suspension spring spacing between said sprung and unsprung masses, electrically controlled exhaust valve means for exhausting pressurized gas from said sleeve to decrease the height of said column of gas to thereby decrease the suspension spring spacing between said sprung and unsprung masses, cap means operatively connecting one end of said sleeve to said sprung mass of said vehicle, a sensor unit supported by said cap means, an insert extending into said sensor unit through the under side of said cap means to form an elongated recess pneumatically connected to said column of gas, first and second magnets vertically spaced from one another and supported in said sensor units adjacent to a first side of said recess, first and second Hall effect device means vertically spaced from one another and supported in said sensor unit for respectively sensing the magnetic field of said first and second magnets, follower means attached to said unsprung mass of said vehicle, said follower means having a van portion adapted to interrupt the fields of said magnets when inserted a pre-determined distance into said recess, electrically energizable circuit means operatively connected to said Hall device means for triggering said compressor means and said exhaust valve means in response to the positioned said vane means with respect to said recess to effect supply of pressurized gas to said chamber when said masses are disposed at a pre-determined minimal distance from another and exhaust pressurized gas from said chamber when said masses are disposed at a pre-determined maximum distance from one another, said Hall effect device means having a null zone permitting limited relative movement between said minimal and maximum distances without triggering operation of said compressor means and said exhaust valve said means.

5. A suspension and leveling system for maintaining a vehicle at a set trim height having sprung and unsprung masses, a polymeric rolling lobe sleeve adjustable in length interconnecting said sprung and unsprung masses, said sleeve confining a column of gas subject to compression and expansion and whose elasticity provides a spring resiliently mounting said sprung mass over said unsprung mass, control means for supplying gas to said sleeve to increase the gas pressure therein to elongate the same to increase the distance between said sprung and unsprung masses, said control means further incorporation gas pressure exhaust means for exhausting pressurized gas from said chamber to decrease the length of said chamber and thereby the distance between said sprung and unsprung masses, first and second magnetic means within said gas chamber providing separate magnetic fields which extends externally of said sleeve, a pair of follower means of unequal length separately mounting said magnetic means for movement in a pre-determined path within the limits of said sleeve, connector means operatively connecting said follower means to at least one of said masses so that said follower means and said magnetic means move in said path distances proportional to the relative movement of said masses, sensor means external of said magnetic means for sensing movement of said magnetic means and triggering said controls to effect supply of pressurized gas to said chamber when said masses are disposed at a pre-determined minimal distance from another and exhaust pressurized gas from said chamber when said masses are disposed at a pre-determined maximum distance from one another, said sensor having a null zone permitting limited movement of said sprung mass relative to said unsprung mass between said minimal and maximum distances without gas being supplied to or exhausted from said cylinder, and means extending externally of said spring for adjusting said follower means with respect to at least one of said masses to thereby adjust the trim height of said vehicle.

6. In a level control system for an automotive vehicle having sprung and unsprung masses, air spring means yieldably interconnecting said sprung and unsprung masses, movable follower means within said air spring means reflecting the distance between said sprung and unsprung masses, compressor means pneumatically connected to said air spring means for supplying pressurized gas thereto for increasing the length of the column of gas confined therein, exhaust valve means for exhausting gas from said air spring means to decrease the length of the column of gas confined in said air spring, Hall effect device means responsive to the distance between said sprung and unsprung masses and the corresponding movement of said follower means for controlling said compressor means and said exhaust valve means to accordingly lengthen or shorten said gas column, said control means including means to establish a trim zone of a predetermined width and adjustment means for adjusting said follower means within said air spring means for widening or narrowing said trim zone.