WO2008143450A1

WO2008143450A1 - Inspection apparatus and method of tone wheel for vehicle

Info

Publication number: WO2008143450A1
Application number: PCT/KR2008/002799
Authority: WO
Inventors: Jaehwan Song; Jin Hur
Original assignee: Yusung Ft
Priority date: 2007-05-21
Filing date: 2008-05-20
Publication date: 2008-11-27
Also published as: KR20080102492A; KR100871933B1

Abstract

The present invention relates to an inspection apparatus and method of tone wheel for a vehicle in order to improve performance of devices, such as ABS, TCS, and VDC, by using tone wheels that have excellent performance and have passed close inspection for completed tone wheels, for a product.

Description

INSPECTION APPARATUS AND METHOD OF TONE WHEEL

FOR VEHICLE

Technical Field

[1] The present invention relates to an inspection apparatus and method of tone wheel for a vehicle that closely inspects a tone wheel for a vehicle that has been completed, to determine whether there is a defect or not. Background Art

[2] In general, a tone wheel is a part that is equipped to a rotary body, such as a drive shaft or a wheel, to detect a rotational speed of the rotary body.

[3] As an example of the tone wheel, a tone wheel 10 in FIG. 1, which is equipped to a hub 1 of a wheel to detect the rotational speed of the wheel of a vehicle.

[4] That is, the tone wheel 10 is fitted in the hub 1 of the wheel and largely includes, as shown in FIGS. 2 and 3, a circular hub 11 in which the hub 1 is fitted, a sensing unit 13 that has a plurality of sensing holes 13a formed at regular distances and ribs 13b therebetween in the circumferential direction, forming prominences and depressions, and a connecting portion 15 that connects the hub 11 with the sensing unit 13. Further, the tone wheel 10 has a cylindrical shape with a multi-stage.

[5] A tone wheel sensor 3, which is disposed around the tone wheel 10 as shown in FIG.

1, detects a pulse generated by from the sensing unit 13 via the sensing holes 13a while the tone wheel 10 rotates with the rotary body.

[6] Further, a controller equipped in the vehicle analyzes the pulse transmitted from the tone wheel sensor 3 and can check the rotational speed of the wheel in real time.

[7] The tone wheel 10 and the tone wheel sensor 3 as described above are used as essential components, including the controller, for ABS (Anti-Lock Brake System), TCS (Traction Control System), and VDC (Vehicle Dynamic Control System).

[8] Therefore, the tone wheel 10 should be able to precisely check the rotational speed of a rotary body, such as a wheel, in real time. Accordingly, the sensing unit 13 that is the object detected by the tone wheel sensor 3 should be formed in a substantially perfect circle with a smooth circumference and have a uniform cross-sectional thickness, and the sensing holes 13a should have uniform shapes and the distance between the sensing holes 13a should be uniform.

[9] Further, the hub 11 of the tone wheel should have precise roundness (degree of perfect circle) and a precise diameter.

[10] Unless any one of the above conditions is satisfied, the entire defective ratio of the tone wheel 10 increases. Disclosure of Invention

Technical Problem

[11] Accordingly, it is an object of the invention to provide an inspection apparatus and a method of a tone wheel for a vehicle that makes it possible to sort out defective tone wheel from normal tone wheels by precisely inspecting completed tone wheel in accordance with inspection items. Technical Solution

[12] An inspection apparatus of a tone wheel for a vehicle according to the invention, includes: a center jig that holds a hub of a tone wheel, which is an inspection object, and rotates the tone wheel; a laser sensor that measures distances from ribs of a sensing unit of the tone wheel as much as the number of the ribs while the tone wheel rotates, and measures a gap of one sensing hole and a gap of one rib of the sensing unit as much as the numbers of the sensing holes and ribs, respectively, while the tone wheel rotates; and a controller that calculates results corresponding to degree of perfect circle S of the outer circumference of the sensing unit, single pitch deviation (SPD), total pitch deviation (TPD), and intermediate angles of pitch Pθl, PΘ2, PΘ3... by calculating values measured by using the laser sensor, and discriminates a normal tone wheel and a defective tone wheel by comparing the results with reference values of a normal tone wheel.

[13] Further, a method of inspecting a tone wheel for a vehicle according to the invention, includes: a first inspection that calculates results corresponding to degree of perfect circle S of the outer circumference of a sensing unit of a tone wheel placed on a center jig, single pitch deviation (SPD), total pitch deviation (TPD), and intermediate angles of pitch Pθl, PΘ2, PΘ3... by calculating values measured by using a laser sensor while the tone wheel rotates, and compares the results with reference values of a normal tone wheel.

Advantageous Effects

[14] According to the invention as described above, it is possible to use only normal tone wheel having excellent performance for vehicles by precisely inspecting completed tone wheels, such that it is possible to improve performance of other parts, such as ABS, TCS, VDC. Brief Description of the Drawings

[15] FIG. 1 is a perspective view illustrating an exemplary use of a tone wheel.

[16] FIGS. 2 and 3 are a perspective view and a longitudinal cross-sectional view of the tone wheel shown in FIG. 1.

[17] FIGS. 4 to 6 are a perspective view, a side view, and a plan view illustrating an inspection apparatus of a tone wheel according to the invention. [18] FIGS. 7 to 9 are views illustrating a tone wheel supplying means in the inspection apparatus according to the invention.

[19] FIGS. 10 to 24 are views illustrating a setting jig, a tone wheel moving means, a tone wheel loading means, and a tone wheel inspecting means in the inspection apparatus according to the invention.

[20] FIGS. 25 to 29 are views illustrating a selecting jig, a tone wheel unloading means, and a tone wheel extracting means in the inspection apparatus according to the invention. Mode for the Invention

[21] Embodiments of the invention are described hereafter in detail with reference to the accompanying drawings.

[22] FIGS. 4 to 6 are a perspective view, a side view, and a plan view illustrating an inspection apparatus of a tone wheel according to the invention, in which the same portions as the related art are described with the same reference numerals.

[23] The tone wheel 10 for a vehicle includes, as described above with reference to FIGS.

2 and 3, a circular hub 11, a sensing unit 13 that has a plurality of sensing holes 13a formed at regular distances and ribs 13b therebetween in the circumferential direction, forming prominences and depressions, and a connecting portion 15 that connects the hub 11 with the sensing unit 13. Further, the tone wheel 10 has a cylindrical shape with a multi-stage.

[24] A completed tone wheels 10 having the above configuration are sorted into normal tone wheel and defective tone wheels by an inspection apparatus according to the invention.

[25] That is, the inspection apparatus of the tone wheel 10, as shown in FIGS. 4 to 6, includes: a tone wheel supplying means 20 that sequentially supplies completed tone wheels 10; a tone wheel moving means 40 that forcibly moves the tone wheel 10 supplied from the tone wheel supplying means 20 to a setting jig 30 disposed ahead of the tone wheel supplying means 20; a tone wheel loading means 50 that is disposed around the setting jig 30 movably in the front and up/down directions of the setting jig 30 and picks up and moves the tone wheel 10 from the setting jig 30; a tone wheel inspecting means 60 that measures degree of perfect circle and single pitch deviation (hereafter, referred to as 'SPD'), and total pitch deviation (hereafter, referred to as 'TPD') of the circumference of the sensing unit 13 of the tone wheel 10 supplied from the tone wheel loading means 50, obtains intermediate angels of pitch Pθl, PΘ2, PΘ3..., and measures precision of the inner diameter and roundness (degree of perfect circle) of the hub 11 ; a tone wheel unloading means 80 that is disposed around the tone wheel inspecting means 60 movably in the front direction of the tone wheel inspecting means 60, and picks up and places the tone wheel 10 inspected by the tone wheel inspecting means 60 to a selecting jig 70 positioned ahead of the tone wheel inspecting means 60; and a tone wheel extracting means 90 that sorts out the tone wheels 10 placed on the selecting jig 70 into normal tone wheels and defective tone wheels, by control of a controller that has checked the measured value by the tone wheel inspecting means 10.

[26] In this configuration, the tone wheel supplying means 20, as shown in FIGS. 7 and 9, includes: a first conveyor 21 on which tone wheels 10 are placed regardless of the upside and downside and that is inclined on a supply base 5 such that an end that faces the supply direction of the tone wheel 10 is positioned lower than the other end; an inclined supplier 22 that is connected to an end of the first conveyor 21 to receive the tone wheels 10 from the first conveyor 21 and inclined such that the front end is positioned lower than the other end to roll the tone wheels 10; a pair of inclined distributors 23 that is divided and inclined to the left and the right at the front of the inclined supplier 22 and distributes the tone wheels 10 discharged from the inclined supplier 22 to two supply lines according to the facing-direction of the hubs 11 ; and a pair of second conveyor 24 that horizontally extends in the front direction from the ends of the inclined distributors 23 and supplies the tone wheels 10 with the bottoms of the sensing units 13 facing upward.

[27] The inclined supplier 22 includes: a fixing guide member 22a that is connected vertically downward to the down-positioned end of both ends of the first conveyor 21; a bottom guide member 22c that is attached to the bottom of the fixing guide member 22a and fixed to the base 5 by height adjusting units 22b while the front end facing the inclined distributors 23 is positioned lower than the rear end; and a movement guide member 22e that is parallel with and spaced apart from the fixing guide member 22a and the bottom is in contact with the bottom guide member 22c such that the distance from the fixing guide member 22a can be adjusted by a distance adjusting lever 22d.

[28] Further, the tone wheel moving means 40, as shown in FIGS. 10 to 12, is an air pusher 41 that is positioned such that an end is fixed to the side of the front end of the second conveyor 24 and the other end is positioned in the rear of the most front tone wheel 10 on the second conveyor 10 to forcibly move the tone wheel 10 from the second conveyor 24 to the setting jig 30 using air pressure that is rapidly discharged.

[29] Further, the setting jig 30, as shown in FIG. 13, includes a jig body 31 that is fixed to an inspection base 6 disposed at a side of the supply base 5 at the same height as the second conveyor 24 and a stopper block 32 that has an insertion groove 32a to restrict movement of the tone wheel 10 that has been moved from the second conveyor 24 to the setting jig 30 by the air pusher 41 , and is fixed to the jig body 31.

[30] Further, the tone wheel loading means 50, as shown in FIG. 13, includes: a loading base bracket 51 that is fixed to the inspection base 6 at a side of the setting jig 30; a loading horizon guide bracket 52 that is connected to the upper end portion of the loading base bracket 51 while facing the front area where the tone wheel inspecting means 60 is positioned, and has a plurality of integrally formed horizon guide rods 52a inside; a loading horizontal moving cylinder 53 that is provided to the loading horizon guide bracket 52 such that it can reciprocate along the horizon guide rods 52a; a loading vertical cylinder 55 that is positioned at a side of the loading horizon movement cylinder 53 and fixed to the loading cylinder bracket 54 protruding to face the setting jig 30 while having an integrally formed vertical cylinder rod 55a that vertically moves up/down through the loading cylinder bracket 54; an ascent-descent block 56 that is a circular plate connected to an end of the vertical cylinder rod 55 a; a pair of loading electromagnetic members 57 that is connected with the ascent-descent block 56 while ends protrude downward from the ascent-descent block 56, and is temporarily combined with the tone wheel 10 placed on the setting jig 30 by an magnetic force that is generated when power is supplied; and a loading approach sensor 58 that is connected to the ascent-descent block 56 together with the loading electromagnetic member 57 and detects whether the tone wheel 10 is placed on the setting jig 30.

[31] Further, the tone wheel inspecting means 60, as shown in FIGS. 14 to 24, includes: a circular rotary plate 61 that is positioned ahead of the setting jig 30 on the inspection base 6 to be rotated by power of a step motor 61a and has a plurality of seating grooves 61b that is symmetrically formed along the outer circumference to fit the tone wheels 10 conveyed through the tone wheel loading means 50; a center jig 63 that is positioned on the inspection base 6 vertically connected with the seating groove 61b between the setting jig 30 and the rotary plate 61 to move up/down and rotate, and measures the degree of perfect circle, SPD, and TPD of the outer circumference of the sensing unit 13 provided to the tone wheel 10 using a measuring means 62 positioned at a side while estimating the intermediate angles of pitch Pθl, PΘ2, PΘ3...; and an air jig 64 that is positioned on the inspection base 6 vertically connected with the seating groove 61b between the rotary plate 61 and the selecting jig 70 to move up/down and rotate, and measures the precision of the inner diameter and roundness (degree of perfect circle) of the hub 11 of the tone wheel 10 using air pressure while temporarily fixing the tone wheel 10 that has passed the center jig 63 together with the tone wheel unloading means 80.

[32] The seating groove 61b is formed in a step shape having a stepped surface 61c at the middle portion such that the connecting portion 15 of the tone wheel 10 is placed on the stepped surface 61c.

[33] The center jig 63 includes: a center jig cylinder 102 that is fixed to the inspection base 6 by a cylinder bracket 101; an outer case 103 that is provided to move up/down through the center jig cylinder 102; a first servo motor 105 that is fixed to a side of the outer case 103 by a motor bracket 104; a cylinder block 106 that is connected with the lower end of the outer case 103 and has a chamber 106a therein, which is open to the outside through an air passage 106b; a piston rod 107 that is disposed in the chamber 106a to move up/down through the chamber 106a by air pressure supplied through the air passage 106b; a lower block 108 that is connected with the piston rod 107 at the lower end in the outer case 103; an upper block 109 that is placed on the lower block 108, a center shaft 111 that is connected with the upper block 109 by a lower bolt 110 and positioned at the center along the length of the outer case 103 while having a shaft protrusion I l ia that protrudes along the circumference over the upper end of the outer case 103; a shaft case 112 that surrounds the center shaft 111; a jig pulley 114 that is fitted on the shaft case 112 in the outer case 103, connected with the first servo motor 105 through a timing belt 113, and rotates the shaft case 112 using power transmitted from the first servo motor 105; a compression spring 115 that is fitted on the shaft case 112 and supported between the upper block 109 and the jig pulley 114; an inner rod 117 that is fitted on the portion over the upper end of the outer case 103 of the center shaft 111 while the lower end is placed on the shaft protrusion I l ia and the upper end is connected with the center shaft 111 by an upper bolt 116, in which the outer circumference of upper end is a tapered surface 117a of which the diameter gradually increases upward; and an outer jaw 118 that is fitted between the inner rod 117 and the shaft case 112 and of which the outer side of the lower end is thread- fastened to the shaft case 112 and the upper end over the upper end of the shaft case 112 radially opens and elastically returns while the inner rod 117 moves up/down to temporarily hold and fix the inner side of the hub 111 of the tone wheel 10 placed in the seating groove 61b of the rotary plate 61.

[34] The measuring means 62 includes a sensor bracket 121 that is fixed to the inspection base 6 at a side of the center jig 63 and a laser sensor 122 that is attached to the sensor bracket 121 horizontally facing the sensing hole 13a while the hub 11 of the tone wheel 10 is held and fixed by the outer jaw 118 of the center jig 63.

[35] The upper end of the outer jaw 118 is formed in a cylindrical shape having a space

118a to insert the upper end of the inner rod 117, the inlet of the space 118a has a slope 118b that contacts with the tapered surface 117a of the inner rod 117, and the cylindrical portion formed by the space 118a is composed of a plurality of cut pieces 118c disposed along the outer circumference to achieve the structure that radially opens and elastically returns by the up/down movement of the inner rod 117.

[36] The air jig 64 includes: an air jig cylinder 132 that is fixed to the inspection base 6 by a cylinder bracket 131; a rotary shaft case 133 that moves up/down through the air jig cylinder 132; a second servo motor 135 that is fixed on a case cover 134 combined with the rotary shaft case 133 at a side of the rotary shaft case 133; a rotary shaft 139 that passes upward through the rotary shaft case 133, is connected with the rotary shaft case 133 and the second servo motor 135 by a bearing 136, and a driving gear 137 and a driven gear 138, respectively, to freely rotate in the rotary shaft case 133 by power of the second servo motor 135, and has an air passage 139a passing through both longitudinal ends; and an air probe 140 of which the lower end is fitted in a connecting groove 139b at the upper end of the rotary shaft 139 to be connected to with the rotary shaft 139, the upper end has a protrusion 140a that is inserted into the hub 11 of the tone wheel 10 in the seating groove 61b of the rotary plate 61 when moving up by the operation of the air jig cylinder 132 and a seating surface 140b that is stepped to place the bottom of the hub 11. Further, the air probe 140 has a main passage 140c that is communicated straight with the air passage 139a and extends into the protrusion 140a and a support passage 14Od that is divided into T-shape at the end of the main passage 140c and open to the outside through the protrusion 140a.

[37] Further, the tone wheel unloading means 80, as shown in FIGS. 23, 25, and 26, includes: an unloading base bracket 81 that is fixed on the inspection base 6 at a side of the selecting jig 70; an unloading horizon guide bracket 82 that is connected with the upper end of the unloading base bracket 81 such that both ends face the air jig 64 and the selecting jig 70, respectively, and has a plurality of horizon guide rods 82a disposed in the longitudinal direction; an unloading horizon movement cylinder 83 that is attached to the unloading horizon guide bracket 82 to reciprocate along the unload horizon guide rods 82a; an unloading cylinder bracket 84 that is attached to a side of the unloading horizon movement cylinder 83 and protrudes toward the air jig 64; a circular plate block 85 that is attached to the bottom of an end of the unloading cylinder bracket 84; a pair of unloading electromagnetic member 86 that is attached to the circular plate block 85 while the ends protrude downward from the circular plate block 85, and temporarily combined with the tone wheel 10 placed on the air jig 64 by a magnetic force that is generated when power is supplied; and an unloading approach sensor 87 that is combined with the circular plate block 85 together with the unloading electromagnetic member 86 and detects whether there is the tone wheel 10 on the air jig 64.

[38] Further, the tone wheel extracting means 90, as shown in FIGS. 27 to 29, includes: a first extracting cylinder 91 that is attached to a side of the unloading horizon movement cylinder 83 while being spaced apart from the unloading cylinder bracket 84 in the front direction toward the selecting jig 70 and has cylinder rods 91a that operate vertically downward; an extracting block 92 that is attached to the lower end of the cylinder rods 91a to protrude parallel with the unloading cylinder bracket 84 and discharges the tone wheel 10 placed on the selecting jig 70 from the selecting jig 70 by pushing the rear side of the tone wheel 10 by the operation of the unloading horizon movement cylinder 83; an extracting plate 93 that pivotably connected to the front end of the selecting jig 70 by a hinge; and a second extracting cylinder 94 that is disposed in the selecting jig 70 and of which an end is connected to the selecting jig 70 and the other end is connected to the extracting plate 93 to incline the extracting plate 93 downward with respect to the selecting jig 70 and selectively pivot the extracting plate 93 downward by control of the controller.

[39] On the other hand, an inspection method of the tone wheel according to the invention will be described with description of the operation of the inspection apparatus.

[40] The operation and effect of the inspection apparatus of a tone wheel according to the invention is described hereafter.

[41] A plurality of tone wheels 10 that is completed to have the sensing unit with the hub

11, sensing holes 13a, ribs 13b, and the connecting portion 15 is supplied onto the first conveyor 2, as shown in FIG. 7.

[42] The upside and downside of the tone wheel 10 are not discriminated.

[43] That is, the tone wheel 10 may be supplied while the hub 11 faces upward or, on the contrary, the sensing unit 13 faces upward.

[44] The tone wheels 10 move along the first conveyor 2 and fall to the bottom guide member 22c of the inclined supplier 22.

[45] The tone wheels 10 falling to the bottom guide member 22c stand on the sides, as shown in FIGS. 8 and 9, and move in a line by the inclination angle of the bottom guide member 22c while rolling.

[46] The tone wheels 10 that have passed the bottom guide member 22c are distributed to the pair of inclined distributors 23.

[47] That is, when passing the bottom guide member 22c, the tone wheels 10 with the hubs 11 facing the left inclined distributor 23 are supplied to the left inclined distributor 23 as shown in FIG. 8, and the tone wheels 10 with the hubs 1 lfacign the right inclined distributor 23 are supplied to the right inclined distributor 23 as shown in FIG. 9.

[48] The sensing unit 13 of each of the tone wheels 10 placed on the left and right inclined distributors 23 face upward.

[49] The tone wheels 10 that have passed the left and right inclined distributors 23, as shown in FIGS. 7 and 10, are sequentially moved along the second conveyor 24 composed of two lines and then temporarily placed and fixed one by one onto the setting jig 30 by the operation of the air pusher 41.

[50] That is, as shown in FIGS. 11 and 12, when the tone wheel 10 moving on the second conveyor 24 is positioned at the end of the second conveyor 24, a sensor (not shown) detects that there is the tone wheel 10 and the air pusher 41 is operated in response to a control signal of the controller (not shown) to momentarily jet air with high pressure to the rear side of the tone wheel 10.

[51] Accordingly, the tone wheel 10 at the end of the second conveyor 24 passes the second conveyor 24 by the air force and positioned onto the jig body 31 of the setting jig 30.

[52] The tone wheel 10 moves from the second conveyor 24 to the jig body 31 is stopped by the stopper block 32 in order not to pass the setting jig 30 while being inserted into the insertion groove 32a of the stopper block 32 and temporarily fixed.

[53] When the tone wheel 10 is inserted in the insertion groove 32a of the stopper block

32, the tone wheel 10 is positioned vertically under the ascent-descent block 56 while the loading horizon movement cylinder 53 of the tone wheel loading means 50 has moved to the rearmost end toward the second conveyor 24.

[54] After the tone wheel 10 is fixed on the setting jig 30, the loading electromagnetic member 57 is magnetized by power that applied to the loading electromagnetic member 57, while the ascent-descent block 56 is moved down, as shown in FIG. 13, by the operation of the loading vertical cylinder 55 and the tone wheel 10 sticks to the loading electromagnetic member 57.

[55] After the tone wheel 10 sticks to the loading electromagnetic member 57, the ascent- descent block 56 picks up the tone wheel 10 from the setting jig 30 while moving up, and the loading horizon movement cylinder 53 moves in the front direction toward the tone wheel inspecting means 60 along the horizon guide rods 52a and then the ascent- descent block 56 moves down again.

[56] As the ascent-descent block 56 moves down, the tone wheel 10 sticking to the loading electromagnetic member 57 is inserted and placed in the seating groove 61b of the rotary plate 6, as shown in FIG. 14, while the power supplied to the loading electromagnetic member 57 is stopped and the tone wheel 10 is correspondingly separated from the loading electromagnetic member 57.

[57] After the tone wheel 10 is separated from the loading electromagnetic member 57, the ascent-descent block 56 moves up and the loading horizon movement cylinder 53 moves back toward the second conveyor 24, such that the tone wheel loading means 50 prepares the next operation.

[58] On the other hand, after the tone wheel 10 is placed in the seating groove 61b and the tone wheel loading means 50 returns to the initial position, as shown in FIGS. 15 to 17, the center jig 63 is entirely moved up by operation of the center jig cylinder 102. Accordingly, the upper end of the outer jaw 118 of the center jig 63 moves up the tone wheel 10 while contacting with the flange shaft 11 of the tone wheel 10, and as a result, the tone wheel 10 placed in the seating groove 61b comes out of the seating groove 61b and positioned over the rotary plate 61. [59] In this position, air is supplied through the air passage 106b of the center jig 63, the piston rod 107, the lower block 108, and the upper block 109 correspondingly move up and the compression spring 115 is compressed, while the center shaft 111 and the inner rod 117 also moves up. [60] As the inner rod 117 moves up, the cut pieces 118c of the outer jaw 118 that have been radially opened elastically move inside with the diameter decreased, in which the upper end of the outer jaw 118 in inserted into the hub 11 of the tone wheel 10. [61] That is, the tone wheel 10 freely falls and the upper end of the outer jaw 118 is fitted into the hub 11. [62] After the upper end of the outer jaw 118 in the hub 11 of the tone wheel 10, the air is stopped and discharged from the center jig 63 and the piston rod 107, lower block 108, upper block 109, center shaft 111, and inner rod 117, which have moved up, are moved down to the initial positions by the return force of the compression spring 115. [63] As the inner rod 117 moves down, the cut pieces 118c of the outer jaw 118 elastically open again, and accordingly, the inside of the hub 11 contacts with the cut pieces 118c and the tone wheel 10 is placed on the upper end of the outer jaw 118 and the position is fixed. [64] After the tone wheel 10 is fixed to the center jig 63 as described above, the first motor 105 is operated to rotate the jig pulley 114 through the timing belt 113 and the shaft case 112, outer jaw 118, inner rod 117, and the center shaft 111 are rotated by the rotation of the jig pulley 114, such that tone wheel 10 is rotated correspondingly. [65] Since the bearing 119 is interposed between the shaft case 112 and the outer case

103, the outer case 103 does not rotate. [66] While the tone wheel 10 rotates, a step of first inspection starts, in which the degree of perfect circle, SPD, and TPD of the outer circumference of the sensing unit 13 are measured and the intermediate angles of pitch Pθl, PΘ2, PΘ3... are obtained by the laser sensor 122. [67] First, a method of inspecting the degree of perfect circle of the outer circumference of the sensing unit 13 in the step of first inspection is as follows. [68] The distance Dl between the laser sensor 122 and the ribs 13b of the sensing unit 13 can be measured by radiating light of the laser sensor 122 to the sensing unit 13 while the tone wheel 10 rotates, as shown in FIG. 17. [69] The distance Dl between the laser sensor 122 and the ribs 13b is measured as much as the number of all of the ribs 13b of the sensing unit 13 (Dl, D2, D3...). [70] In general, the sensing unit 13 of the tone wheel 10 has thirty sensing holes 13a and sixty ribs 13b along the circumference. [71] The measured distances Dl, D2, D3... are transmitted to the controller, the controller obtains a result S that is obtained by subtracting the minimum value DMIN from the maximum value DMAX in the all of the measured distances Dl, D2, D3..., and it is determined that the tone wheel 10 is in a normal state, only when the result S is in a range of a reference value SC.

[72] Second, a method of inspecting SPD in the step of first inspection is as follows.

[73] A pitch Pl can be measured by adding a gap of one sensing hole 13a and a gap of one rib 13b that are measured by radiating light of the laser sensor 122 to the sensing unit 13 while the tone wheel 10 rotates, as shown in FIG. 18. [74] The other pitches P2, P3... are measured as much as the number of all of the sensing holes 13a and the ribs 13b. [75] All of the pitches Pl, P2, P3... measured as described above are transmitted to the controller and then the controller calculates an average PA of the pitches Pl, P2, P3.... [76] After the average PA is obtained, SPD 1 , SPD2, SPD3... are obtained by

[77] Formula 1) SPDl = { (PA - Pl)/( PA )}*100

[78] Formula 2) SPD2 = { (PA - P2)/( PA )}*100

[79] Formula 3) SPD3 = { (PA - P3)/( PA )}*100

[80] and then the absolute quantity of the maximum value SPDMAX of the SPD 1 , SPD2,

SPD3... is obtained as a result SPD. [81] It is determined that the tone wheel 10 is in a normal state, when the result SPD is in a range of a reference value SPDC.

[82] Third, a method of inspecting TPD in the step of first inspection is as follows.

[83] After estimating the SPD 1 , SPD2, SPD3... , the controller obtains all of TPD 1 ,

TPD2, TPD3... using the following formulae. [84] Formula 4) TPD 1 = SPD 1

[85] Formula 5) TPD2 = SPD 1 + SPD2

[86] Formula 6) TPD3 = SPD2 + SPD3

[87] Thereafter, the controller obtains a result TPD by subtracting the minimum value

TPDMIN from the maximum value TPDMAX in all of TPDl, TPD2, TPD3..., and it is determined that the tone wheel 10 is in a normal state, only when the result TPD is in a range of a reference value TPDC. [88] Fourth, the intermediate angles of pitch Pl, P2, P3... in the step of first inspection each are obtained by the following methods. [89] That is, the controller obtains a total pitch PT by adding all of the pitches Pl, P2,

P3... obtained in the previous step (PT = P1+P2+P3...). [90] Further, as shown in FIG. 19, since the total of the intermediate angles of pitch Pθl,

PΘ2, PΘ3... is 360° (PΘT = Pθl + PΘ2 + PΘ3...), the intermediate angles of pitch Pθl,

PΘ2, PΘ3 are each obtained by the following formulae. [91] Formula 7) Pθl = (PΘT * Pl)/ PT [92] Formula 8) PΘ2 = (PΘT * P2)/ PT

[93] Formula 9) PΘ3 = (PΘT * P3)/ PT....

[94] After the first inspection is finished at the center jig 63, air is supplied again to the air passage 106b of the center jig 63, such that, as described above, the center shaft 111 and the inner rod 117 move up and the cut pieces 118c of the outer jaw 118 are moved inside.

[95] In this position, as the center jig 63 are entirely moved down by the operation of the center jig cylinder 102, the tone wheel 10 fixed to the outer jaw 118 is separated from the center jig 63 and inserted and placed in the seating groove 61b of the rotary plate 61, as shown in FIG. 14.

[96] After the first inspection is finished at the center jig 63 and the tone wheel 10 is inserted again in the seating groove 61b of the rotary plate 61, the rotary plate 61 is rotated at 180° by the step motor 61a and the tone wheel that has undergone the first inspection is positioned over the air jig 64, as shown in FIG. 20.

[97] After the tone wheel 10 that has undergone the first inspection is positioned over the air jig 64, the air jig 64 is entirely moved up by the operation of the air jig cylinder 132, and accordingly, the protrusion 140a of the air probe 140 of the air jig 64, as shown in FIGS. 21 and 22, is inserted into the hub 11 of the tone wheel 10 while the lower end of the hub 11 is placed on the seating surface 140b, such that the tone wheel 10 is moved up. As a result, the tone wheel 10 placed on the seating groove 61b is separated upward from the seating groove 61b.

[98] When the tone wheel 10 is separated upward from the seating groove 61b, the unloading electromagnetic member 86 is magnetized by the power that is supplied to the unloading electromagnetic member 86, such that the tone wheel 10 placed on the air probe 140 and moving up sticks to the unloading electromagnetic member 86, as shown in FIG. 23.

[99] After the tone wheel 10 sticks to the unloading electromagnetic member 86, a step of second inspection that measures the precision of the inner diameter and roundness (degree of perfect circle) of the hub 11 is started.

[100] First, a method of inspecting the precision of the inner diameter of the hub 11 in the step of second inspection is as follows.

[101] With the tone wheel 10 fixed between the air probe 140 and the unloading electromagnetic member 86, when air at high pressure is momentarily supplied through the air pipe 141, the air is finally jetted out through the support passage 14Od and hits to the first two points of the inside of the hub 11.

[102] The pressure MPl, MP2 generated at the two points, as shown in FIG. 24, are displayed by a plurality of pressure display 151 provided on the supply base 5 and the controller measure the pressure MPl, MP2 at the two points. [103] After the pressure MPl, MP2 at the first two points are measured, the second servo motor 135 is driven, and the power is transmitted to the rotary shaft 139 through the driving gear 137 and driven gear 138. Accordingly, the rotary shaft 139, the air probe 140, and the tone wheel 10 are rotated at 120° in one direction and then stopped.

[104] After the tone wheel 10 is rotated at 120° and stopped, air is jetted again through the support passage 14Od and the controller measures the pressure MP3, MP4 at the next two points to which the air hits.

[105] When the tone wheel 10 is rotated again at 120° in the same way and then stopped and the air is jetted, the controller measures the pressure at the final two points MP5, MP6 to which the air hits.

[106] When the pressure of all of the points MPl, MP2, MP3, MP4, MP5, MP6 is measured, the controller obtains an average MPA of all of the pressure, and it is determined that the tone wheel 10 is in a normal state, when the result (average) is in a range of a reference value MPCl.

[107] Second, a method of inspecting the roundness (degree of perfect circle) in the step of second inspection is as follows.

[108] That is, the controller calculates a result MP by subtracting the minimum value

MPMIN from the maximum value MPMAX in the pressure MPl, MP2, MP3, MP4, MP5, MP6 of all the points obtained in the previous step, and it is determined that the tone wheel 10 is in a normal state, only when the result MP is in a range of a reference value MPC2.

[109] After the second inspection is finished at the air jig 64 is finished as described above, the air jig 64 is entirely moved down by the operation of the air jig cylinder 132 and returns to the initial position as shown in FIG. 25, and accordingly, the air probe 140 is detached from the hub 11, such that the tone wheel 10 sticks to the unloading electromagnetic member 86 and picked up from the air jig 64.

[110] After the tone wheel 10 is picked up, the unloading horizon movement cylinder 83 moves in the front direction toward the selecting jig 70 through the horizon guide rod 82a such that the tone wheel 10 is positioned over the selecting jig 70, while the power supplied to the unloading electromagnetic member 86 is stopped and the tone wheel 10 sticking to the unloading electromagnetic member 86 is placed on the selecting jig 70, as shown in FIG. 26.

[I l l] After the tone wheel 10 is placed on the selecting jig 70 as described above, the unloading horizon movement cylinder 83 returns back toward the air jig 64 along the horizon guide rod 82a.

[112] The first extracting cylinder 91 attached to the unloading horizon movement cylinder 83 is also moved back, in which the extracting block 92 moves down and, as shown in FIG. 27, positioned behind the tone wheel 10 placed on the selecting jig 70. [113] After the extracting block 92 is positioned behind the tone wheel 10, the unloading horizon movement cylinder 83 moves again in the front direction toward the selecting jig 70 along the horizon guide rod 82a, as shown in FIG. 28, in which the extracting block 92 pushes the rear side of the tone wheel 10, such that the tone wheel 10 that has undergone the first and second inspection is extracted from the selecting jig 70.

[114] On the other hand, when all the inspection data of the tone wheel 10 that is extracted from the selecting jig 70 are normal, the extracting plate 93 maintains the position shown in FIG. 29, such that normal tone wheels 10 are collected through the extracting plate 93 and the upper plate 153 (shown in FIG. 4).

[115] Further, any one of the inspection data of the tone wheel 10 that is extracted from the selecting jig 70 is abnormal, the extracting plate 93 is rotated in the direction of an arrow Rl from the position shown in FIG. 29 by the operation of the second extracting cylinder 94, and accordingly, defective tone wheels are collected through the extracting plate 93 and the lower plate 155 (shown in FIG. 4).

[116] Therefore, by inspecting the completed tone wheel 10 using the inspection apparatus according to the invention, it is possible to precisely and closely check whether the tone wheel 10 has defect, such that it is possible to basically prevent use of a defective tone wheel.

[117] As a result, it is possible to improve performance of ABS, TCS, and VDC using the tone wheel 10 without defect.

Claims

[1] An inspection apparatus of a tone wheel for a vehicle, comprising: a center jig that holds a hub of a tone wheel, which is an inspection object, and rotates the tone wheel; a laser sensor that measures distances Dl from ribs of a sensing unit of the tone wheel as much as the number of the ribs while the tone wheel rotates, and measures a gap of one sensing hole and a gap of one rib of the sensing unit as much as the numbers of the sensing holes and ribs, respectively, while the tone wheel rotates; and a controller that calculates results corresponding to degree of perfect circle S of the outer circumference of the sensing unit, single pitch deviation (SPD), total pitch deviation (TPD), and intermediate angles of pitch Pθl, PΘ2, PΘ3... by calculating values measured by using the laser sensor, and discriminates a normal tone wheel and a defective tone wheel by comparing the results with reference values of a normal tone wheel.

[2] The inspection apparatus according to claim 1, further comprising: an air jig that jets air to the inside of the hub of the tone wheel, which is the inspection object, while holding the hub to measure precision of the inner diameter and roundness (degree of perfect circle) of the hub of the tone wheel, wherein the controller further has a function of calculating results MPA, MP corresponding to the precision of the inner diameter and the roundness (degree of perfect circle) of the hub by calculating values measured by using the air jig, and then discriminating a normal tone wheel and a defective tone wheel by comparing the results with reference values of a normal tone wheel.

[3] The inspection apparatus according to claim 1, wherein the center jig includes: an outer case that is provided to move up/down through a center jig cylinder; a first servo motor that is fixed to a side of the outer case; a cylinder block that is connected with the lower end of the outer case, and has a chamber therein, the chamber being open to the outside through an air passage; a piston rod that is disposed in the chamber to move up/down through the chamber by air pressure supplied through the air passage; an upper block that is placed on a lower block that is connected with the piston rod at the lower end in the outer case; a center shaft that is connected with the upper block and positioned at the center of the outer case along the length of the outer case while having a shaft protrusion that protrudes along the circumference over the upper end of the outer case; a jig pulley that is fitted on the shaft case that surrounds the center shaft and rotates the shaft case using power transmitted from the first servo motor; a compression spring that is fitted on the shaft case and supported between the upper block and the jig pulley; an inner rod that is fitted on the portion over the upper end of the outer case of the center shaft while the lower end is placed on the shaft protrusion and the upper end is connected with the center shaft, in which the outer circumference of upper end is a tapered surface of which the diameter gradually increases upward; and an outer jaw that is fitted between the inner rod and the shaft case and of which the lower end is fastened to the shaft case and the upper end over the upper end of the shaft case radially opens and elastically returns while the inner rod moves up/down to temporarily hold and fix the inner side of the hub of the tone wheel.

[4] The inspection apparatus according to claim 3, wherein the upper end of the outer jaw is formed in a cylindrical shape having a space to insert the upper end of the inner rod, the inlet of the space has a slope that contacts with the tapered surface of the inner rod, and the cylindrical portion formed by the space is composed of a plurality of cut pieces disposed along the outer circumference to achieve the structure that radially opens and elastically returns by the up/down movement of the inner rod.

[5] The inspection apparatus according to claim 2, wherein the air jig includes: a rotary shaft case that moves up/down through an air jig cylinder; a second servo motor that is fixed to a side of the rotary shaft case; a rotary shaft that passes upward through the rotary shaft case, freely rotates in the rotary shaft case by power of the second servo motor, and has an air passage passing through both longitudinal ends; and an air probe that is connected to the upper end of the rotary shaft, and of which the upper end has a protrusion that is inserted into the hub of the tone wheel and a seating surface that is stepped to place the bottom of the hub, the air probe having a main passage that is communicated straight with the air passage and a plurality of support passages that are divided into T-shape at the end of the main passage and pass through the outer circumference of the protrusion.

[6] A method of inspecting a tone wheel for a vehicle, comprising: a first inspection that calculates results corresponding to degree of perfect circle S of the outer circumference of a sensing unit of a tone wheel placed on a center jig, single pitch deviation (SPD), total pitch deviation (TPD), and intermediate angles of pitch Pθl, PΘ2, PΘ3... by calculating values measured by using a laser sensor while the tone wheel rotates, and compares the results with reference values of a normal tone wheel.

[7] The method according to claim 6, further comprising: a second inspection that calculates results MPA, MP corresponding to precision of the inner diameter and roundness (degree of perfect circle) of a hub and compares the results with a reference of a normal tone wheel by jetting air using the air jig to the inside of a hub of the tone wheel while holding the tone wheel placed on the air jig and measuring pressure at the position inside the hub where the air is jetted.

[8] The method according to claim 6, wherein a method of inspecting the degree of perfect circle S of the outer diameter of the sensing unit in the first inspection includes: measuring the distance Dl between a laser sensor and ribs of the sensing unit as much as the number of all of the ribs of the sensing unit (Dl, D2, D3...), while the tone wheel fixed to the center jig rotates; calculating a result S that is obtained by subtracting the minimum value DMIN from the maximum value DMAX in the all of the measured distances Dl, D2,

D3...; and determining that the tone wheel is in a normal state, when the result S is in a range of a reference value SC, by a controller.

[9] The method according to claim 6, wherein a method of inspecting the single pitch deviation SPD in the first inspection includes: obtaining a pitch Pl by measuring and adding a gap of one sensing hole and a gap of one rib of the sensing unit while the tone wheel fixed to the center jig rotate; measuring the other pitches P2, P3... are measured as much as the number of all of the sensing holes and the ribs and calculating an average PA of the pitches Pl,

P2, P3....; calculating SPDl, SPD2, SPD3... using

Formula 1) SPDl = { (PA - Pl)/( PA )}*100

Formula 2) SPD2 = { (PA - P2)/( PA )}*100

Formula 3) SPD3 = { (PA - P3)/( PA )}*100; calculating the absolute quantity of the maximum value SPDMAX of the SPDl,

SPD2, SPD3... as a result SPD; and determining that the tone wheel is in a normal state, when the result SPD is in a range of a reference value SPDC by the controller.

[10] The method according to claim 9, wherein a method of inspecting total pitch deviation TPD in the first inspection includes: obtaining all of TPDl, TPD2, TPD3... using the following formulae,

Formula 4) TPDl = SPDl

Formula 5) TPD2 = SPDl + SPD2

Formula 6) TPD3 = SPD2 + SPD3; calculating a result TPD by subtracting the minimum value TPDMIN from the maximum value TPDMAX in all of TPDl, TPD2, TPD3...; and determining that the tone wheel is in a normal state, when the result TPD is in a range of a reference value TPDC by the controller.

[11] The method according to claim 9, wherein a total pitch (PT = P1+P2+P3...) is obtained by adding all of pitches Pl, P2, P3... obtained as much as the number of the sensing holes and ribs, and the intermediate angles of pitch Pθl, PΘ2, PΘ3 are each obtained by the following formulae,

Formula 7) Pθl = (PΘT * Pl)/ PT

Formula 8) PΘ2 = (PΘT * Yl)I PT

Formula 9) PΘ3 = (PΘT * P3)/ PT. since the total of the intermediate angles of pitch Pθl, PΘ2, PΘ3... is 360° (PΘT

= PΘ1 + PΘ2 + PΘ3...).

[12] The method according to claim 7, wherein a method of inspecting the precision of the inner diameter of the hub of the tone wheel in the second inspection, includes: measuring pressures MPl, MP2 generated at first two points of the inside of the hub when air is momentarily jetted through support passages of the air jig while fixing the tone wheel placed on the air jig; measuring pressure MP3, MP4 at next two points by jetting air again after the tone wheel rotates at a predetermined angle from the first two points where the pressure MPl, MP2 is measured; measuring pressure MP5, MP6 at final two positions by jetting air again after the tone wheel rotates at a predetermined angle from the two points where the pressure MP3, MP4 is measured; and determining that the tone wheel is in a normal state, when a result of an average

MPA of all of the pressure MPl, MP2, MP3, MP4, MP5, MP6 is in a rage of a reference value MPCl by the controller.

[13] The method according to claim 12, all of the pressure MPl, MP2, MP3, MP4,

MP5, MP6 is measured while the support passage of the air jig rotates by 120°.

[14] The method according to claim 12, a method of inspecting the roundness (degree of perfect circle) of the hub of the tone wheel in the second inspection, includes: calculating a result MP by subtracting the minimum value MPMIN from the maximum value MPMAX of all of the pressure MPl, MP2, MP3, MP4, MP5, MP6 measured for the inside of the hub; and determining that the tone wheel is in a normal state by the controller, when the result MP is in a rage of a reference value MPC2.

[15] The method according to claim 7, wherein it is determined that the tone wheel is in a normal state, only when all of the inspection data of the tone wheel that passes the first inspection and the second inspection satisfies a reference value for a normal tone wheel.