US20140167486A1 - Sensor Mounting System For Road Milling Machine - Google Patents
Sensor Mounting System For Road Milling Machine Download PDFInfo
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- US20140167486A1 US20140167486A1 US13/714,994 US201213714994A US2014167486A1 US 20140167486 A1 US20140167486 A1 US 20140167486A1 US 201213714994 A US201213714994 A US 201213714994A US 2014167486 A1 US2014167486 A1 US 2014167486A1
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- machine
- attachment
- road milling
- sensor
- relative
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- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01C—CONSTRUCTION OF, OR SURFACES FOR, ROADS, SPORTS GROUNDS, OR THE LIKE; MACHINES OR AUXILIARY TOOLS FOR CONSTRUCTION OR REPAIR
- E01C23/00—Auxiliary devices or arrangements for constructing, repairing, reconditioning, or taking-up road or like surfaces
- E01C23/06—Devices or arrangements for working the finished surface; Devices for repairing or reconditioning the surface of damaged paving; Recycling in place or on the road
- E01C23/08—Devices or arrangements for working the finished surface; Devices for repairing or reconditioning the surface of damaged paving; Recycling in place or on the road for roughening or patterning; for removing the surface down to a predetermined depth high spots or material bonded to the surface, e.g. markings; for maintaining earth roads, clay courts or like surfaces by means of surface working tools, e.g. scarifiers, levelling blades
- E01C23/085—Devices or arrangements for working the finished surface; Devices for repairing or reconditioning the surface of damaged paving; Recycling in place or on the road for roughening or patterning; for removing the surface down to a predetermined depth high spots or material bonded to the surface, e.g. markings; for maintaining earth roads, clay courts or like surfaces by means of surface working tools, e.g. scarifiers, levelling blades using power-driven tools, e.g. vibratory tools
- E01C23/088—Rotary tools, e.g. milling drums
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- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01C—CONSTRUCTION OF, OR SURFACES FOR, ROADS, SPORTS GROUNDS, OR THE LIKE; MACHINES OR AUXILIARY TOOLS FOR CONSTRUCTION OR REPAIR
- E01C19/00—Machines, tools or auxiliary devices for preparing or distributing paving materials, for working the placed materials, or for forming, consolidating, or finishing the paving
- E01C19/004—Devices for guiding or controlling the machines along a predetermined path
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- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01C—CONSTRUCTION OF, OR SURFACES FOR, ROADS, SPORTS GROUNDS, OR THE LIKE; MACHINES OR AUXILIARY TOOLS FOR CONSTRUCTION OR REPAIR
- E01C23/00—Auxiliary devices or arrangements for constructing, repairing, reconditioning, or taking-up road or like surfaces
- E01C23/06—Devices or arrangements for working the finished surface; Devices for repairing or reconditioning the surface of damaged paving; Recycling in place or on the road
- E01C23/12—Devices or arrangements for working the finished surface; Devices for repairing or reconditioning the surface of damaged paving; Recycling in place or on the road for taking-up, tearing-up, or full-depth breaking-up paving, e.g. sett extractor
- E01C23/122—Devices or arrangements for working the finished surface; Devices for repairing or reconditioning the surface of damaged paving; Recycling in place or on the road for taking-up, tearing-up, or full-depth breaking-up paving, e.g. sett extractor with power-driven tools, e.g. oscillated hammer apparatus
- E01C23/127—Devices or arrangements for working the finished surface; Devices for repairing or reconditioning the surface of damaged paving; Recycling in place or on the road for taking-up, tearing-up, or full-depth breaking-up paving, e.g. sett extractor with power-driven tools, e.g. oscillated hammer apparatus rotary, e.g. rotary hammers
Definitions
- the present disclosure relates generally to a sensor mounting system for a road milling machine and, more particularly, to a sensor mounting system including an inboard ground engaging unitary ski member supporting a position sensor.
- a road milling machine includes a plurality of ground engaging members supporting a machine frame of the road milling machine.
- the ground engaging members may include wheels or tracks, and may be connected to the machine frame through lifting columns.
- the lifting columns allow independent adjustment at each corner of the machine frame to facilitate various orientations of the machine frame relative to a ground surface to be treated, such as, for example, a paved surface.
- a rotor is supported by the machine frame and oriented perpendicularly relative to a longitudinal centerline of the road milling machine for treating or, for example, milling the paved surface.
- height adjustable side plates are positioned at opposite side ends of the rotor and define outer walls of the road milling machine. The side plates rest on the paved surface being treated and, thus, are raised relative to the machine frame as the machine frame is lowered during the milling process.
- position sensors are often positioned to measure vertical movement of the side plates relative to the machine frame, or one another, to arrive at a milling depth, and/or inclination, of the rotor.
- the measurements obtained by these position sensors may be inaccurate in particular scenarios. For example, when milling an edge of the paved surface being treated, one of the side plates may rest on an unpaved surface, which may include grass, rocks, or soil, rather than the paved surface. As such, the calculated milling depth at the edge may be inaccurate and may necessitate measurements by hand during the milling operation.
- Wirtgen GmbH a company headquartered in Windhagen, Germany, offers hydraulic milling depth sensors that capture the level on the sides and in front of a milling drum, as shown in the Wirtgen publication page submitted herewith.
- the Wirtgen hydraulic milling depth sensors positioned inboard relative to side plates flanking the milling drum appear to be supported near the ground surface by a pair of pivotably connected linear arms.
- the inboard hydraulic milling depth sensors of Wirtgen may provide one solution to the edge surface treatment problem described above, there is a continuing need to provide highly accurate sensors and sensor mounting arrangements for calculating milling depth.
- the present disclosure is directed to one or more of the problems or issues set forth above.
- a road milling machine in one aspect, includes a machine frame carried by a plurality of ground engaging members, and a rotor supported by the machine frame and oriented perpendicularly relative to a longitudinal centerline of the road milling machine for treating a ground surface.
- First and second side plates are arranged at opposite side ends of the rotor.
- the road milling machine also includes a sensor mounting system.
- the sensor mounting system includes a first mounting member, which is attached to a first machine component and supports a first portion of a position sensor, and a second mounting member attached to a second machine component having a pivotable attachment to the machine frame.
- An extension member has a first end attached to the second mounting member and a second end including an attachment flange.
- a unitary ski member has a first end attached to a second portion of the position sensor and a second end pivotably attached to the attachment flange.
- the unitary ski member includes a ground engaging surface that is positioned inboard relative to the first and second side plates and has a pivot movement compensation curve.
- a controller of the road milling machine is configured for determining a milling depth of the rotor from measurements obtained by the position sensor.
- a sensor mounting system for a road milling machine includes a first mounting member configured for attachment to a first machine component of the road milling machine and configured to support a portion of a position sensor.
- a second mounting member is configured for attachment to a second machine component having a pivotable attachment to a machine frame.
- An extension member has a first end configured for attachment to the second mounting member such that the extension member extends perpendicularly relative to a longitudinal centerline of the road milling machine, and a second end configured for attachment to an attachment flange.
- a unitary ski member has a first end configured for attachment to another portion of the position sensor and a second end configured for pivotable attachment to the attachment flange.
- the unitary ski member includes a ground engaging surface that is positioned inboard relative to the first and second side plates and has a pivot movement compensation curve.
- a method for measuring a milling depth of a road milling machine having the sensor mounting system described above includes moving the road milling machine, via a plurality of ground engaging members, in a forward travel direction along a ground surface.
- a rotor supported on a frame of the road milling machine is lowered to a predetermined milling depth to treat the ground surface.
- the ground surface to be treated is contacted with the ground engaging surface of the unitary ski member at a first position along the pivot movement compensation curve of the ground engaging surface.
- the first position is a predetermined distance from a first ski attachment location of the unitary ski member and the position sensing device.
- a first milling depth of the rotor is determined using a controller from measurements obtained by the position sensor responsive to contacting the ground surface at the first position.
- a second ski attachment location of the unitary ski member and the attachment flange is pivoted relative to the machine frame.
- the ground surface to be treated is contacted with the ground engaging surface of the unitary ski member at a second position along the pivot movement compensation curve.
- the second position is the same predetermined distance from the first ski attachment location.
- a second milling depth of the rotor is determined using a controller from measurements obtained by the position sensor responsive to contacting the ground surface at the second position.
- FIG. 1 is a perspective view of a road milling machine in which features of the present disclosure may be incorporated;
- FIG. 2 is a perspective view of a chamber of the road milling machine, according to the present disclosure
- FIG. 3 is a different perspective view of the chamber of FIG. 2 , showing an exemplary embodiment of a sensor mounting system according to the present disclosure
- FIG. 4 is a perspective view of components of the exemplary sensor mounting system of FIG. 3 , according to the present disclosure
- FIG. 5 is another exemplary embodiment of a sensor mounting system which may be incorporated onto the road milling machine of FIG. 1 , according to the present disclosure
- FIG. 6 is a perspective view of components of an exemplary sensor mounting system, shown at a first orientation, according to the present disclosure.
- FIG. 7 is a perspective view of components of the exemplary sensor mounting system of FIG. 6 , shown at a second orientation, according to the present disclosure.
- an exemplary road milling machine 10 may generally include a machine frame 12 carried by a plurality of ground engaging members 14 .
- the ground engaging members 14 may include wheels or tracks (as shown), and may be connected to the machine frame 12 through lifting columns 16 .
- the lifting columns 16 allow independent adjustment at each corner of the machine frame 12 to facilitate various orientations of the machine frame 12 relative to a ground surface to be treated, such as, for example, a paved surface S.
- a rotor 18 is supported by the machine frame 12 and oriented perpendicularly relative to a longitudinal centerline C of the road milling machine 10 for treating or, for example, milling the paved surface S.
- the rotor 18 may be fitted with cutting tools and, as the road milling machine 10 moves in a forward travel direction F, the rotor 18 may be rotated, such as in a counterclockwise direction relative to the forward travel direction F, to remove material from the paved surface S. According to some embodiments, the removed material may be lifted using a conveyor system 20 to a dump truck (not shown) traveling in front of the road milling machine 10 .
- a chamber 22 houses the rotor 18 and includes a first height adjustable side plate 24 and a second height adjustable side plate 26 (not shown) positioned at opposite side ends of the rotor 18 .
- the first and second side plates 24 and 26 define outer walls, which rest on the paved surface S being treated.
- the side plates 24 and 26 are raised relative to the machine frame 12 as the machine frame 12 is lowered during the milling operation.
- An anti-slab device 28 may be supported on a portion of the machine frame 12 , such as the chamber 22 , forward of the rotor 18 relative to the forward travel direction F.
- the anti-slab device 28 may press down on the paved surface S being treated to prevent large slabs from breaking out of the pavement layer.
- a scraper 30 also referenced as a moldboard, may be provided rearward of the rotor 18 relative to the forward travel direction F for smoothing the milled surface.
- the machine frame 12 may also support an operator control station 32 having a variety of components and controls useful in operating the road milling machine 10 .
- the operator control station 32 may include devices for controlling engine operation, propulsion, steering, milling depth, rotor operation, and conveyor operation, to name a few.
- the road milling machine 10 may include an engine, such as an internal combustion engine, for powering the various systems and devices of the road milling machine 10 , including the systems and devices described above.
- the road milling machine 10 may include at least one controller 34 , such as a programmed computer logic and associated memory, for translating input commands received from various input devices, or controllers, of the road milling machine 10 into command signals for controlling the appropriate system or device of the machine 10 .
- the road milling machine 10 may include additional controls positioned at the sides of the machine 10 and/or near the ground engaging members 14 for more precisely controlling the milling operation while walking alongside the road milling machine 10 .
- each of the first and second side plates 24 and 26 may include an outboard position sensing device 40 positioned outboard relative to the first and second side plates 24 and 26 .
- the second side plate 26 may represent a mirror image of the first side plate 24 and may also include a position sensing device similar to the depicted outboard position sensing device 40 .
- the outboard position sensing device 40 may include a wire rope sensor 42 , or an alternative position sensing device, positioned and configured to measure the vertical displacement of a ground engaging portion 44 of the first side plate 24 with respect to the chamber 22 .
- the displacement which is measured near a rotational axis A of the rotor 18 (not shown in FIG. 2 ), may be used to calculate the current milling depth, as is known in the art.
- the vertical displacements of the first and second side plates 24 and 26 may be measured with respect to each other to determine an inclination of the chamber 22 with respect to the paved surface S to be treated.
- the road milling machine 10 may include one or more inboard position sensing devices 46 , positioned inwardly relative to the first and second side plates 24 and 26 .
- the inboard position sensing devices 46 may each include a sensor mounting system 50 .
- Each of the sensor mounting systems 50 may generally include a first mounting member 52 attached to a machine component, such as, for example, the chamber 22 and supporting a first portion 54 of a wire rope sensor 56 , or other position sensor.
- a second mounting member 58 may be attached to the anti-slab device 28 , or another machine component having a pivotable attachment to the machine frame 12 and/or chamber 22 .
- An extension member 60 may have a first end 62 attached to the second mounting member 58 and a second end 64 including an attachment flange 66 .
- Each sensor mounting system 50 may also include a unitary ski member 68 having a first end 70 attached to a second portion 72 of the wire rope sensor 56 and a second end 74 pivotably attached to the attachment flange 66 .
- a ground engaging surface 76 of the unitary ski member 68 may include a pivot movement compensation curve 78 .
- the first mounting member 52 may be attached to the chamber 22 , or other machine component, at a first mounting location 80 and the second mounting member 58 may be attached to the anti-slab device 28 at a second mounting location 82 that is forward of the first mounting location 80 relative to the forward travel direction F of the road milling machine 10 .
- the second mounting location 82 may be inwardly spaced from the first mounting location 80 relative to the longitudinal centerline C.
- the extension member 60 may extend perpendicularly relative to the longitudinal centerline C of the road milling machine 10 to properly align the components, namely the first mounting member 52 and the unitary ski member 68 , supporting the first and second portions 54 and 72 of the wire rope sensor 56 .
- the road milling machine 10 may include two inboard position sensing devices 46 , which may be mirror images of one another, laterally spaced relative to the longitudinal centerline C and positioned inboard relative to the first and second side plates 24 and 26 .
- the first and second inboard position sensing devices 46 may be configured to measure the displacement of ground engaging surfaces 76 of the unitary ski members 68 with respect to the chamber 22 and/or with respect to each other to determine current milling depth and/or inclination of the chamber 22 .
- the controller 34 may be configured to determine the milling depth of the rotor 18 from measurements obtained by the wire rope sensors 56 , or other known position sensors.
- the first mounting member 52 may be configured as a plate or bracket 90 structured and arranged for coupling to the chamber 22 , or other portion of the machine frame 12 .
- the plate 90 may have an angled surface complementary to the angled surface of the chamber 22 . Openings 92 in the plate may be aligned with openings in the chamber 22 such that fasteners (not shown) may be received through the openings 92 to mount the plate 90 to the frame 12 .
- fasteners not shown
- the first mounting member 52 may also include an adjustable sensor mount 94 for attaching the first portion 54 , or base, of the wire rope sensor 56 .
- the adjustable sensor mount 94 may permit vertical movement and rotational movement of the wire rope sensor 56 prior to fixing a desired position.
- the second mounting member 58 may similarly be configured as a plate 96 structured and arranged for coupling to the anti-slab device 28 .
- the plate 96 may have an angled surface complementary to the angled surface of the anti-slab device 28 .
- the plate 96 may have a bolted connection to the anti-slab device 28 or may be connected in a variety of other known ways.
- the extension member 60 may be configured as a tube 98 with the first end 62 coupled, such as via U-bolts, with the second mounting member 58 and the second end 64 defining the substantially planar attachment flange 66 arranged perpendicularly to the longitudinal direction of the extension member 60 .
- the longitudinal dimension of the extension member 60 extends substantially laterally relative to the road milling machine 10 , for example, substantially perpendicular to the forward travel direction F, as shown in FIG. 3 .
- the unitary ski member 68 is pivotably coupled with the attachment flange 66 such that the unitary ski member 68 extends behind the extension member 60 relative to the forward travel direction F of the machine 10 .
- the unitary ski member 68 may include an opening therethrough for receiving a sleeve-bearing.
- the unitary ski member 68 may rotate about the sleeve-bearing, with a bolt, washer, and nut holding the sleeve-bearing tightly against the attachment flange 66 .
- Clearances may be provided on either side of the unitary ski member 68 at the joint and/or between the unitary ski member 68 and the sleeve-bearing to improve rotation of the unitary ski member 68 .
- the unitary ski member 68 may be removably coupled with the attachment flange 66 so that the unitary ski member 68 can be replaced after a predetermined amount of wear.
- the first end 70 of the unitary ski member 68 may include a hook 100 for receiving a wire 102 of the wire rope sensor 56 .
- the tube 98 may include an extended portion 104 extending through an opening 106 through the attachment flange 66 .
- the extended portion 104 may be configured to restrict pivotable movement of the unitary ski member 68 to reduce potential damage of the wire rope sensor 56 .
- a bottom surface 112 of the unitary ski member 68 may contact the extended portion 104 , which may prevent rotation of the unitary ski member 68 beyond a predetermined lengthening of the wire 102 .
- a locking pin 108 may be positioned through openings in the unitary ski member 68 and attachment flange 66 to secure a raised position (shown at 114 ) of the unitary ski member 68 , which may be useful when the inboard position sensing device 46 is not in use.
- An additional opening through the attachment flange 66 may be provided to receive and store the locking pin 108 when the inboard position sensing device 46 is in use and/or a raised position is not desired.
- the inboard position sensing devices 46 may include position sensing cylinders 120 .
- the sensor mounting systems 50 of the embodiment of FIG. 5 are similar to those shown in FIG. 4 and, as such, corresponding or similar reference numbers are used to refer to the same or corresponding parts. Differences between the embodiments of FIG. 4 and FIG. 5 include alternative first mounting members 52 and alternative attachment means incorporated with the unitary ski members 68 .
- the first mounting members 52 may include alternative plates 122 configured for engagement with the machine frame 12 and also configured for pivotable attachment of the position sensing cylinders 120 .
- the unitary ski members 68 may similarly be adapted for pivotable attachment with the position sensing cylinders 120 .
- a raised position of the unitary ski members 68 may be facilitated by refraction of the position sensing cylinders 120 and, thus, the locking pin 108 of the embodiment of FIG. 4 may be unnecessary.
- the road milling machine 10 equipped with the inboard position sensing devices 46 described herein may be operated in the following manner in order to measure the current milling depth of the machine 10 .
- the road milling machine 10 may be moved, via the plurality of ground engaging members 14 , in a forward travel direction F along the paved surface S.
- the rotor 18 supported on the machine frame 12 , may be lowered to a predetermined milling depth to treat the paved surface S.
- the paved surface S to be treated may be contacted with the ground engaging surface 76 of the unitary ski member 68 at a first position 130 along the pivot movement compensation curve 78 .
- the first position 130 is a predetermined distance d 1 from a first ski attachment location 132 , which is the location at which the unitary ski member 68 is attached to the wire 102 .
- a first milling depth may then be determined via the controller 34 using measurements obtained by the wire rope sensor 56 .
- the unitary ski member 68 is attached to the second mounting member 58 via the extension member 60 and attachment flange 66 at a second ski attachment location 134 .
- the second mounting member 58 may be attached to the anti-slab device 28 , which is pivotable relative to the machine frame 12 .
- the anti-slab device 28 may pivot about a pivot axis 136 as the anti-slab device 28 encounters unevenness of the paved surface S.
- the orientation of the anti-slab device 28 about the pivot axis 136 may change as a bottom surface 138 of the anti-slab device 28 wears.
- the pivot movement compensation curve 78 which corresponds to the ground engaging surface 76 of the unitary ski member 68 , represents a curvature of the ground engaging surface 76 that compensates for the movement of the anti-slab device 28 about the pivot axis 136 .
- the second ski attachment location 134 will be shifted along a vertical axis.
- the second ski attachment location 134 may be raised relative to the machine frame 12 as a result of the pivotable movement of the anti-slab device 28 in a first direction.
- the paved surface S may be contacted with the ground engaging surface 76 of the unitary ski member 68 at a second position 140 along the pivot movement compensation curve 78 .
- the second position 140 is spaced from the first position 130 along the pivot movement compensation curve 78 and has a distance d 2 from the first ski attachment location 132 that is the same as, or substantially similar to, the distance d 1 between the first position 130 and the first ski attachment location 132 .
- a second milling depth may then be determined via the controller 34 using measurements obtained by the wire rope sensor 56 .
- the second ski attachment location 134 may be lowered relative to the machine frame 12 .
- the unitary ski member 68 will be pivoted such that the paved surface S is contacted with the ground engaging surface 76 of the unitary ski member 68 at a third position (not shown) along the pivot movement compensation curve 78 .
- the third position may be spaced from the first position 130 along the pivot movement compensation curve 78 in a direction opposite the spacing of the second position 140 from the first position 130 .
- the third position may also have a distance (not shown) from the first ski attachment location 132 that is the same, or substantially similar to, the distances d 1 and d 2 between the first and second positions 130 and 140 and the first ski attachment location 132 .
- the first and second milling depths may have improved accuracy based on the inboard position sensing devices 46 described herein and based, more particularly, on the sensor mounting systems 50 disclosed herein.
- the pivot movement compensation curve 78 may be configured such that each ground engaging location along the pivot movement compensation curve 78 is the same distance from the first ski attachment location 132 .
- the pivot movement compensation curve 78 may also span the entire ground engaging surface 76 of the unitary ski member 68 , which may include all potential ground engaging locations that may result from the pivotable movement range of the anti-slab device 28 and resulting vertical movement of the second ski attachment location 134 .
- One or both of the inboard position sensing devices 46 may be used in combination with or as alternatives to outboard position sensing devices 40 .
- one or both of the inboard position sensing devices 46 may be particularly useful when milling an edge of the paved surface S. Locating the inboard position sensing devices 46 inboard relative to the side plates 24 and 26 avoids the inaccuracies that may result from utilizing the outboard position sensing devices 40 supported on the side plates 24 and 26 .
- one of the side plates 24 and 26 may rest on an unpaved surface, which may include grass, rocks, or soils, rather than the paved surface S, and may result in inaccurate milling depth measurements.
Abstract
Description
- The present disclosure relates generally to a sensor mounting system for a road milling machine and, more particularly, to a sensor mounting system including an inboard ground engaging unitary ski member supporting a position sensor.
- A road milling machine includes a plurality of ground engaging members supporting a machine frame of the road milling machine. The ground engaging members may include wheels or tracks, and may be connected to the machine frame through lifting columns. The lifting columns allow independent adjustment at each corner of the machine frame to facilitate various orientations of the machine frame relative to a ground surface to be treated, such as, for example, a paved surface. A rotor is supported by the machine frame and oriented perpendicularly relative to a longitudinal centerline of the road milling machine for treating or, for example, milling the paved surface. Typically, height adjustable side plates are positioned at opposite side ends of the rotor and define outer walls of the road milling machine. The side plates rest on the paved surface being treated and, thus, are raised relative to the machine frame as the machine frame is lowered during the milling process.
- Due to the close proximity of the side plates to the rotational axis of the rotor, position sensors are often positioned to measure vertical movement of the side plates relative to the machine frame, or one another, to arrive at a milling depth, and/or inclination, of the rotor. Although acceptable in most circumstances, the measurements obtained by these position sensors may be inaccurate in particular scenarios. For example, when milling an edge of the paved surface being treated, one of the side plates may rest on an unpaved surface, which may include grass, rocks, or soil, rather than the paved surface. As such, the calculated milling depth at the edge may be inaccurate and may necessitate measurements by hand during the milling operation.
- Wirtgen GmbH, a company headquartered in Windhagen, Germany, offers hydraulic milling depth sensors that capture the level on the sides and in front of a milling drum, as shown in the Wirtgen publication page submitted herewith. In particular, the Wirtgen hydraulic milling depth sensors positioned inboard relative to side plates flanking the milling drum appear to be supported near the ground surface by a pair of pivotably connected linear arms. Although the inboard hydraulic milling depth sensors of Wirtgen may provide one solution to the edge surface treatment problem described above, there is a continuing need to provide highly accurate sensors and sensor mounting arrangements for calculating milling depth.
- The present disclosure is directed to one or more of the problems or issues set forth above.
- In one aspect, a road milling machine includes a machine frame carried by a plurality of ground engaging members, and a rotor supported by the machine frame and oriented perpendicularly relative to a longitudinal centerline of the road milling machine for treating a ground surface. First and second side plates are arranged at opposite side ends of the rotor. The road milling machine also includes a sensor mounting system. The sensor mounting system includes a first mounting member, which is attached to a first machine component and supports a first portion of a position sensor, and a second mounting member attached to a second machine component having a pivotable attachment to the machine frame. An extension member has a first end attached to the second mounting member and a second end including an attachment flange. A unitary ski member has a first end attached to a second portion of the position sensor and a second end pivotably attached to the attachment flange. The unitary ski member includes a ground engaging surface that is positioned inboard relative to the first and second side plates and has a pivot movement compensation curve. A controller of the road milling machine is configured for determining a milling depth of the rotor from measurements obtained by the position sensor.
- In another aspect, a sensor mounting system for a road milling machine includes a first mounting member configured for attachment to a first machine component of the road milling machine and configured to support a portion of a position sensor. A second mounting member is configured for attachment to a second machine component having a pivotable attachment to a machine frame. An extension member has a first end configured for attachment to the second mounting member such that the extension member extends perpendicularly relative to a longitudinal centerline of the road milling machine, and a second end configured for attachment to an attachment flange. A unitary ski member has a first end configured for attachment to another portion of the position sensor and a second end configured for pivotable attachment to the attachment flange. The unitary ski member includes a ground engaging surface that is positioned inboard relative to the first and second side plates and has a pivot movement compensation curve.
- In another aspect, a method for measuring a milling depth of a road milling machine having the sensor mounting system described above includes moving the road milling machine, via a plurality of ground engaging members, in a forward travel direction along a ground surface. A rotor supported on a frame of the road milling machine is lowered to a predetermined milling depth to treat the ground surface. The ground surface to be treated is contacted with the ground engaging surface of the unitary ski member at a first position along the pivot movement compensation curve of the ground engaging surface. The first position is a predetermined distance from a first ski attachment location of the unitary ski member and the position sensing device. A first milling depth of the rotor is determined using a controller from measurements obtained by the position sensor responsive to contacting the ground surface at the first position. A second ski attachment location of the unitary ski member and the attachment flange is pivoted relative to the machine frame. The ground surface to be treated is contacted with the ground engaging surface of the unitary ski member at a second position along the pivot movement compensation curve. The second position is the same predetermined distance from the first ski attachment location. A second milling depth of the rotor is determined using a controller from measurements obtained by the position sensor responsive to contacting the ground surface at the second position.
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FIG. 1 is a perspective view of a road milling machine in which features of the present disclosure may be incorporated; -
FIG. 2 is a perspective view of a chamber of the road milling machine, according to the present disclosure; -
FIG. 3 is a different perspective view of the chamber ofFIG. 2 , showing an exemplary embodiment of a sensor mounting system according to the present disclosure; -
FIG. 4 is a perspective view of components of the exemplary sensor mounting system ofFIG. 3 , according to the present disclosure; -
FIG. 5 is another exemplary embodiment of a sensor mounting system which may be incorporated onto the road milling machine ofFIG. 1 , according to the present disclosure; -
FIG. 6 is a perspective view of components of an exemplary sensor mounting system, shown at a first orientation, according to the present disclosure; and -
FIG. 7 is a perspective view of components of the exemplary sensor mounting system ofFIG. 6 , shown at a second orientation, according to the present disclosure. - Referring now to
FIG. 1 , an exemplaryroad milling machine 10, referenced also as a cold planer, may generally include amachine frame 12 carried by a plurality ofground engaging members 14. Theground engaging members 14 may include wheels or tracks (as shown), and may be connected to themachine frame 12 throughlifting columns 16. Thelifting columns 16 allow independent adjustment at each corner of themachine frame 12 to facilitate various orientations of themachine frame 12 relative to a ground surface to be treated, such as, for example, a paved surfaceS. A rotor 18 is supported by themachine frame 12 and oriented perpendicularly relative to a longitudinal centerline C of theroad milling machine 10 for treating or, for example, milling the paved surface S. Therotor 18 may be fitted with cutting tools and, as theroad milling machine 10 moves in a forward travel direction F, therotor 18 may be rotated, such as in a counterclockwise direction relative to the forward travel direction F, to remove material from the paved surface S. According to some embodiments, the removed material may be lifted using aconveyor system 20 to a dump truck (not shown) traveling in front of theroad milling machine 10. - A
chamber 22 houses therotor 18 and includes a first heightadjustable side plate 24 and a second height adjustable side plate 26 (not shown) positioned at opposite side ends of therotor 18. The first andsecond side plates side plates machine frame 12 as themachine frame 12 is lowered during the milling operation. Ananti-slab device 28 may be supported on a portion of themachine frame 12, such as thechamber 22, forward of therotor 18 relative to the forward travel direction F. Theanti-slab device 28 may press down on the paved surface S being treated to prevent large slabs from breaking out of the pavement layer. Ascraper 30, also referenced as a moldboard, may be provided rearward of therotor 18 relative to the forward travel direction F for smoothing the milled surface. - The
machine frame 12 may also support anoperator control station 32 having a variety of components and controls useful in operating theroad milling machine 10. For example, theoperator control station 32 may include devices for controlling engine operation, propulsion, steering, milling depth, rotor operation, and conveyor operation, to name a few. Although not shown, it should be appreciated that theroad milling machine 10 may include an engine, such as an internal combustion engine, for powering the various systems and devices of theroad milling machine 10, including the systems and devices described above. Further, theroad milling machine 10 may include at least onecontroller 34, such as a programmed computer logic and associated memory, for translating input commands received from various input devices, or controllers, of theroad milling machine 10 into command signals for controlling the appropriate system or device of themachine 10. According to some embodiments, theroad milling machine 10 may include additional controls positioned at the sides of themachine 10 and/or near theground engaging members 14 for more precisely controlling the milling operation while walking alongside theroad milling machine 10. - Turning now to
FIG. 2 , portions of thechamber 22 are shown with several components of theroad milling machine 10 removed. According to some embodiments, each of the first andsecond side plates position sensing device 40 positioned outboard relative to the first andsecond side plates first side plate 24 is shown, it should be appreciated that thesecond side plate 26 may represent a mirror image of thefirst side plate 24 and may also include a position sensing device similar to the depicted outboardposition sensing device 40. The outboardposition sensing device 40 may include awire rope sensor 42, or an alternative position sensing device, positioned and configured to measure the vertical displacement of aground engaging portion 44 of thefirst side plate 24 with respect to thechamber 22. The displacement, which is measured near a rotational axis A of the rotor 18 (not shown inFIG. 2 ), may be used to calculate the current milling depth, as is known in the art. According to some embodiments, the vertical displacements of the first andsecond side plates chamber 22 with respect to the paved surface S to be treated. - In addition to, or as an alternative to, the one or more outboard
position sensing devices 40, theroad milling machine 10 may include one or more inboardposition sensing devices 46, positioned inwardly relative to the first andsecond side plates FIG. 3 , the inboardposition sensing devices 46 may each include asensor mounting system 50. Each of thesensor mounting systems 50 may generally include a first mountingmember 52 attached to a machine component, such as, for example, thechamber 22 and supporting afirst portion 54 of awire rope sensor 56, or other position sensor. A second mountingmember 58 may be attached to theanti-slab device 28, or another machine component having a pivotable attachment to themachine frame 12 and/orchamber 22. Anextension member 60 may have afirst end 62 attached to the second mountingmember 58 and asecond end 64 including anattachment flange 66. Eachsensor mounting system 50 may also include aunitary ski member 68 having afirst end 70 attached to asecond portion 72 of thewire rope sensor 56 and asecond end 74 pivotably attached to theattachment flange 66. As will be described in greater detail below, aground engaging surface 76 of theunitary ski member 68 may include a pivotmovement compensation curve 78. - The first mounting
member 52 may be attached to thechamber 22, or other machine component, at a first mountinglocation 80 and the second mountingmember 58 may be attached to theanti-slab device 28 at a second mountinglocation 82 that is forward of the first mountinglocation 80 relative to the forward travel direction F of theroad milling machine 10. In addition, the second mountinglocation 82 may be inwardly spaced from the first mountinglocation 80 relative to the longitudinal centerline C. Thus, theextension member 60 may extend perpendicularly relative to the longitudinal centerline C of theroad milling machine 10 to properly align the components, namely the first mountingmember 52 and theunitary ski member 68, supporting the first andsecond portions wire rope sensor 56. - As shown, the
road milling machine 10 may include two inboardposition sensing devices 46, which may be mirror images of one another, laterally spaced relative to the longitudinal centerline C and positioned inboard relative to the first andsecond side plates position sensing devices 46 may be configured to measure the displacement ofground engaging surfaces 76 of theunitary ski members 68 with respect to thechamber 22 and/or with respect to each other to determine current milling depth and/or inclination of thechamber 22. In particular, thecontroller 34 may be configured to determine the milling depth of therotor 18 from measurements obtained by thewire rope sensors 56, or other known position sensors. - Turning now to
FIG. 4 , the components of the inboardposition sensing devices 46 are shown removed from theroad milling machine 10. As shown, the first mountingmember 52 may be configured as a plate orbracket 90 structured and arranged for coupling to thechamber 22, or other portion of themachine frame 12. For example, theplate 90 may have an angled surface complementary to the angled surface of thechamber 22.Openings 92 in the plate may be aligned with openings in thechamber 22 such that fasteners (not shown) may be received through theopenings 92 to mount theplate 90 to theframe 12. However, alternative mounting arrangements, in addition to bolted connections, are also contemplated. The first mountingmember 52 may also include anadjustable sensor mount 94 for attaching thefirst portion 54, or base, of thewire rope sensor 56. Theadjustable sensor mount 94 may permit vertical movement and rotational movement of thewire rope sensor 56 prior to fixing a desired position. - The second mounting
member 58 may similarly be configured as aplate 96 structured and arranged for coupling to theanti-slab device 28. For example, theplate 96 may have an angled surface complementary to the angled surface of theanti-slab device 28. Theplate 96 may have a bolted connection to theanti-slab device 28 or may be connected in a variety of other known ways. Theextension member 60 may be configured as atube 98 with thefirst end 62 coupled, such as via U-bolts, with the second mountingmember 58 and thesecond end 64 defining the substantiallyplanar attachment flange 66 arranged perpendicularly to the longitudinal direction of theextension member 60. The longitudinal dimension of theextension member 60 extends substantially laterally relative to theroad milling machine 10, for example, substantially perpendicular to the forward travel direction F, as shown inFIG. 3 . - The
unitary ski member 68 is pivotably coupled with theattachment flange 66 such that theunitary ski member 68 extends behind theextension member 60 relative to the forward travel direction F of themachine 10. According to a specific example, theunitary ski member 68 may include an opening therethrough for receiving a sleeve-bearing. Theunitary ski member 68 may rotate about the sleeve-bearing, with a bolt, washer, and nut holding the sleeve-bearing tightly against theattachment flange 66. Clearances may be provided on either side of theunitary ski member 68 at the joint and/or between theunitary ski member 68 and the sleeve-bearing to improve rotation of theunitary ski member 68. Thus, according to some embodiments, theunitary ski member 68 may be removably coupled with theattachment flange 66 so that theunitary ski member 68 can be replaced after a predetermined amount of wear. - According to the exemplary embodiment, the
first end 70 of theunitary ski member 68 may include ahook 100 for receiving awire 102 of thewire rope sensor 56. Additional and/or alternative features may also be provided. For example, thetube 98 may include anextended portion 104 extending through anopening 106 through theattachment flange 66. Theextended portion 104 may be configured to restrict pivotable movement of theunitary ski member 68 to reduce potential damage of thewire rope sensor 56. For example, abottom surface 112 of theunitary ski member 68 may contact theextended portion 104, which may prevent rotation of theunitary ski member 68 beyond a predetermined lengthening of thewire 102. According to an additional feature, alocking pin 108 may be positioned through openings in theunitary ski member 68 andattachment flange 66 to secure a raised position (shown at 114) of theunitary ski member 68, which may be useful when the inboardposition sensing device 46 is not in use. An additional opening through theattachment flange 66 may be provided to receive and store thelocking pin 108 when the inboardposition sensing device 46 is in use and/or a raised position is not desired. - According to an alternative embodiment, and as shown in
FIG. 5 , the inboardposition sensing devices 46 may includeposition sensing cylinders 120. Thesensor mounting systems 50 of the embodiment ofFIG. 5 are similar to those shown inFIG. 4 and, as such, corresponding or similar reference numbers are used to refer to the same or corresponding parts. Differences between the embodiments ofFIG. 4 andFIG. 5 include alternative first mountingmembers 52 and alternative attachment means incorporated with theunitary ski members 68. For example, the first mountingmembers 52 may includealternative plates 122 configured for engagement with themachine frame 12 and also configured for pivotable attachment of theposition sensing cylinders 120. Theunitary ski members 68 may similarly be adapted for pivotable attachment with theposition sensing cylinders 120. Features present with the embodiment ofFIG. 4 may be unnecessary for the embodiment ofFIG. 5 . For example, a raised position of theunitary ski members 68 may be facilitated by refraction of theposition sensing cylinders 120 and, thus, the lockingpin 108 of the embodiment ofFIG. 4 may be unnecessary. - The
road milling machine 10 equipped with the inboardposition sensing devices 46 described herein may be operated in the following manner in order to measure the current milling depth of themachine 10. With reference toFIG. 1 , theroad milling machine 10 may be moved, via the plurality ofground engaging members 14, in a forward travel direction F along the paved surface S. Therotor 18, supported on themachine frame 12, may be lowered to a predetermined milling depth to treat the paved surface S. According to the exemplary embodiments ofFIGS. 3 and 4 , and with reference now toFIG. 6 , the paved surface S to be treated may be contacted with theground engaging surface 76 of theunitary ski member 68 at a first position 130 along the pivotmovement compensation curve 78. The first position 130 is a predetermined distance d1 from a first ski attachment location 132, which is the location at which theunitary ski member 68 is attached to thewire 102. A first milling depth may then be determined via thecontroller 34 using measurements obtained by thewire rope sensor 56. - The
unitary ski member 68 is attached to the second mountingmember 58 via theextension member 60 andattachment flange 66 at a second ski attachment location 134. As described above, the second mountingmember 58 may be attached to theanti-slab device 28, which is pivotable relative to themachine frame 12. For example, theanti-slab device 28 may pivot about a pivot axis 136 as theanti-slab device 28 encounters unevenness of the paved surface S. In addition, the orientation of theanti-slab device 28 about the pivot axis 136 may change as a bottom surface 138 of theanti-slab device 28 wears. The pivotmovement compensation curve 78, which corresponds to theground engaging surface 76 of theunitary ski member 68, represents a curvature of theground engaging surface 76 that compensates for the movement of theanti-slab device 28 about the pivot axis 136. - In particular, as the
anti-slab device 28 pivots about the pivot axis 136, the second ski attachment location 134 will be shifted along a vertical axis. For example, during the milling operation, the second ski attachment location 134 may be raised relative to themachine frame 12 as a result of the pivotable movement of theanti-slab device 28 in a first direction. As shown inFIG. 7 , and as a result of the vertical movement of the second ski attachment location 134, the paved surface S may be contacted with theground engaging surface 76 of theunitary ski member 68 at a second position 140 along the pivotmovement compensation curve 78. The second position 140 is spaced from the first position 130 along the pivotmovement compensation curve 78 and has a distance d2 from the first ski attachment location 132 that is the same as, or substantially similar to, the distance d1 between the first position 130 and the first ski attachment location 132. A second milling depth may then be determined via thecontroller 34 using measurements obtained by thewire rope sensor 56. - If the
anti-slab device 28 is pivoted in a second direction that is opposite the first direction, the second ski attachment location 134 may be lowered relative to themachine frame 12. As the second ski attachment location 134 is lowered, theunitary ski member 68 will be pivoted such that the paved surface S is contacted with theground engaging surface 76 of theunitary ski member 68 at a third position (not shown) along the pivotmovement compensation curve 78. As should be appreciated, the third position may be spaced from the first position 130 along the pivotmovement compensation curve 78 in a direction opposite the spacing of the second position 140 from the first position 130. The third position may also have a distance (not shown) from the first ski attachment location 132 that is the same, or substantially similar to, the distances d1 and d2 between the first and second positions 130 and 140 and the first ski attachment location 132. - The first and second milling depths may have improved accuracy based on the inboard
position sensing devices 46 described herein and based, more particularly, on thesensor mounting systems 50 disclosed herein. In particular, the pivotmovement compensation curve 78 may be configured such that each ground engaging location along the pivotmovement compensation curve 78 is the same distance from the first ski attachment location 132. The pivotmovement compensation curve 78 may also span the entireground engaging surface 76 of theunitary ski member 68, which may include all potential ground engaging locations that may result from the pivotable movement range of theanti-slab device 28 and resulting vertical movement of the second ski attachment location 134. - One or both of the inboard
position sensing devices 46 may be used in combination with or as alternatives to outboardposition sensing devices 40. For example, one or both of the inboardposition sensing devices 46 may be particularly useful when milling an edge of the paved surface S. Locating the inboardposition sensing devices 46 inboard relative to theside plates position sensing devices 40 supported on theside plates side plates - It should be understood that the above description is intended for illustrative purposes only, and is not intended to limit the scope of the present disclosure in any way. Thus, those skilled in the art will appreciate that other aspects of the disclosure can be obtained from a study of the drawings, the disclosure and the appended claims.
Claims (20)
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US13/714,994 US8764118B1 (en) | 2012-12-14 | 2012-12-14 | Sensor mounting system for road milling machine |
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US8764118B1 US8764118B1 (en) | 2014-07-01 |
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Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN105714665A (en) * | 2016-03-15 | 2016-06-29 | 湖南三一路面机械有限公司 | Milling machine |
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Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10151071B1 (en) | 2017-06-13 | 2018-12-11 | Caterpillar Paving Products Inc. | Anti-slab height control system for a cold planer |
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Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3877830A (en) * | 1973-08-27 | 1975-04-15 | Renner Co | Towed paver with thickness and leveling control |
US3989402A (en) * | 1973-08-27 | 1976-11-02 | The Renner Company | Paving machine with thickness and leveling control |
US4140420A (en) | 1978-03-16 | 1979-02-20 | Cmi Corporation | Portable grade averaging apparatus |
US4213719A (en) | 1978-09-28 | 1980-07-22 | Cmi Corporation | Grade averaging apparatus |
US4270801A (en) | 1979-08-14 | 1981-06-02 | Cmi Corporation | Steering and cutter drum positioning in a paved roadway planing machine |
US4580923A (en) * | 1984-08-15 | 1986-04-08 | Ingersoll-Rand Company | Actuating means for a servo valve |
US5378081A (en) | 1994-02-16 | 1995-01-03 | Swisher, Jr.; George W. | Milling machine with front-mounted cutter |
DE102006062129B4 (en) * | 2006-12-22 | 2010-08-05 | Wirtgen Gmbh | Road construction machine and method for measuring the cutting depth |
EP2650443B1 (en) | 2006-12-22 | 2021-06-30 | Wirtgen GmbH | Road milling machine with control means for producing parallelism of the machine frame with the ground |
US8794867B2 (en) * | 2011-05-26 | 2014-08-05 | Trimble Navigation Limited | Asphalt milling machine control and method |
-
2012
- 2012-12-14 US US13/714,994 patent/US8764118B1/en active Active
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US11655599B2 (en) | 2006-12-22 | 2023-05-23 | Wirtgen America, Inc. | Road milling machine and method for measuring the milling depth |
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