JP4128919B2 - Method and apparatus for measuring toe angle of automobile - Google Patents

Description

  The present invention relates to a method and an apparatus for measuring a toe angle of an automobile conveyed in a suspended state in an automobile assembly line.

  Conventionally, as a technique for measuring the toe angle of an automobile, for example, one described in Patent Document 1 below is known. In Patent Document 1, a toe angle is measured via a wheel attachment portion without attaching a wheel in an assembly line for assembling an automobile body, thereby improving productivity.

  In this type of measurement method, after a steering device and a suspension device are assembled to a vehicle body conveyed by a hanger in an automobile body assembly line, the vehicle body is first detached from the hanger. At this time, positioning of the vehicle body is performed by fitting a pin of positioning means provided below the vehicle body supported by the hanger into the positioning hole of the vehicle body. When the suspension device is assembled, the vehicle body is supported so as to be movable up and down via a wheel mounting portion provided on the vehicle body. Next, a connecting tool such as a chain provided in the lowering means for lowering the vehicle body is connected to the front and rear of the vehicle body to lower the vehicle body downward, and a predetermined load is applied to the vehicle body. As a result, the suspension device is applied with a biasing force corresponding to a predetermined load by the reaction force from the wheel mounting portion, and the vehicle body is fixed in a state closest to a completed vehicle state in which the wheel is assembled to the axle. And this state is maintained and a toe angle is measured via a wheel attachment part.

  However, according to such a conventional method, it is necessary to reproduce the state closest to the finished vehicle state with respect to the vehicle body, and prior to measuring the toe angle, the operation of positioning the vehicle body separated from the hanger In addition, since the work of pulling downward by the pulling means is required, there is a disadvantage that the man-hour for measurement is relatively large and the efficiency is poor.

  Therefore, it is conceivable to measure the toe angle from the vehicle body supported by the hanger without removing the vehicle body from the hanger. According to this, the work of positioning the vehicle body and the work of pulling downward by the pulling means are unnecessary, and the measurement can be performed efficiently.

However, there is play between the roller provided at the top of the hanger that conveys the vehicle body and the conveyance rail that guides the roller, and the center of gravity of the vehicle body changes due to the influence of each component attached to the vehicle body, so that each hanger In some cases, the posture of the vehicle body is shifted from the predetermined direction to the left or right. For this reason, there is a disadvantage that the toe angle measured from the vehicle body supported by the hanger is inaccurate due to the influence of the posture of the vehicle body at the time of measurement.
Japanese Patent No. 2938984 (FIGS. 1 and 6)

  The present invention eliminates such inconvenience, and the present invention can measure the toe angle quickly and accurately without applying the same load to the wheel mounting portion as in the completed vehicle state, and can improve the productivity. An object of the present invention is to provide a measurement method and an apparatus therefor.

In order to achieve such an object, the present invention is a method for measuring a toe angle of an automobile conveyed in a suspended state in an automobile assembly line, and maintains the suspended state of the automobile body and the wheels are not mounted. The wheel mounting part of the wheel mounting part can be freely raised and lowered, and the wheel mounting part ascending process for raising the wheel mounting part to a predetermined height position, and the position and toe angle of the wheel mounting part during the ascending by the wheel mounting part raising process are measured. In a toe angle measuring method for an automobile comprising a measuring step and a toe angle calculating step for calculating a toe angle in a completed vehicle state of the automobile from a measurement value obtained by the measuring step, the measuring step is predetermined at a measurement position. A thrust that detects the deviation angle of the center line extending in the vehicle length direction of the vehicle body supported in a suspended state as the thrust angle with respect to the correct center line extending in the vehicle length direction of the vehicle body Comprising a corner detection process, and a measurement value correcting step of correcting the measured value of the toe angle based on the thrust angle detected by the thrust angle detection process, the toe angle calculation step, measured at the rising start of the wheel mount A coordinate consisting of the position of the wheel mounting portion measured and the toe angle measured at the position and corrected by the measurement value correcting step is set as a first reference coordinate, and the wheel mounting portion is raised to the predetermined height position. A first reference coordinate using a plurality of coordinates consisting of the position of the wheel mounting portion measured at each predetermined interval until and the toe angle measured at each position and corrected by the measurement value correcting step as measurement coordinates A first calculation step for calculating the slope of each straight line connecting the measurement coordinates and the coordinates of the wheel mounting portion in the first reference coordinates and a correct toe angle predetermined corresponding to the position The second The second reference coordinates calculated in advance are set as quasi-coordinates, and a plurality of coordinates consisting of each position of the wheel mounting portion in each measurement coordinate and a correct toe angle determined in advance corresponding to each position are set coordinates. Based on the difference between the slope of each straight line connecting each set coordinate and the slope of each straight line connecting the first reference coordinate and each measurement coordinate, the toe angle of the position of the wheel mounting portion in the finished vehicle state of the automobile is determined. A second calculation step for calculating an estimated value, and a third calculation for obtaining an amount to be adjusted until the correct toe angle of the position of the wheel mounting portion in the finished vehicle state is obtained based on the value obtained by the second calculation step And a process .

  The present invention eliminates the need for a step of measuring the toe angle while maintaining the suspended state when the vehicle body is transported in a suspended state on the assembly line of the vehicle, and applying the same load to the vehicle body as in the completed vehicle state. The toe angle can be measured efficiently in a short time.

  That is, first, the vehicle body is supported in a suspended state with the wheel attachment portion being raised and lowered, and the wheel attachment portion is raised to a predetermined height position by the wheel attachment portion raising step. At the height position where the wheel mounting portion is raised, for example, when the vehicle body is supported by a hanger in the assembly line of the vehicle body, the height does not rise so as to follow the wheel mounting portion and separate from the hanger. Position. This makes it possible to measure the toe angle in a stable support state without lifting the vehicle body from the hanger. Next, the position and toe angle of the wheel mounting part in the middle of ascending are measured by the measurement process, and the toe angle in the finished vehicle state of the automobile is calculated from the measured values. Thereby, the toe angle in the completed vehicle state of the automobile can be confirmed while the automobile body is supported in a suspended state.

  By the way, since the automobile body is suspended by a hanger or the like, when measuring the position of the wheel mounting portion and the toe angle, the center line extending in the vehicle length direction of the automobile body is a predetermined correct center line. There is a case where they do not coincide with each other, and the deviation angle in the horizontal direction of the center line at this time becomes the thrust angle, and the measured value of the toe angle becomes inaccurate. Therefore, in the measurement process, the lateral angle of the center line is detected as the thrust angle by the thrust angle detection process, and then the measured toe angle is corrected based on the thrust angle by the measurement value correction process. Thereby, the thrust angle can be removed from the measured value of the toe angle, and an accurate measured value of the toe angle can be obtained. Thus, according to the present invention, it is possible to measure the toe angle efficiently and with high accuracy while maintaining the suspended state by the hanger or the like.

In the toe angle calculation step, the toe angle corrected in the measurement value correction step is used. That is, in the first calculation step, first, the position at which the wheel attachment portion is started to rise by the wheel attachment portion raising step and the toe angle at the position are measured, and the measured value of the toe angle is corrected to the measured value. Correct by the process. A coordinate composed of the measured position and the corrected toe angle is set as the first reference coordinate. Next, the position of the wheel mounting portion and the toe angle at each position are measured at predetermined intervals until the wheel mounting portion is raised to the predetermined height position, and each measured value of the toe angle is further measured. It is corrected by the value correction process. Then, a plurality of coordinates including each measured position and the corrected toe angle at each position are set as measurement coordinates. Next, the inclination of each straight line connecting the first reference coordinate and each measurement coordinate is calculated.

In the second calculation step, first, an inclination of each straight line connecting the second reference coordinate calculated in advance and each set coordinate and an inclination of each straight line connecting the first reference coordinate and each measurement coordinate are calculated. Calculate the difference. The second reference coordinates are determined in advance corresponding to the position of the wheel mounting portion of the first reference coordinate (that is, the position where the rising of the wheel mounting portion in the wheel mounting portion raising process is started) and the position. Coordinates with correct toe angle.

Each set coordinate is the position of the wheel mounting portion at each measurement coordinate (that is, the position of the wheel mounting portion measured at a predetermined interval until the wheel mounting portion is raised to the predetermined height position. ) And a correct toe angle determined in advance corresponding to each position.

The inventor performs various tests on the amount of change in the toe angle, and each of the slopes of the straight lines connecting the second reference coordinates and the set coordinates, and the first reference coordinates and the measurement coordinates. It has been found that the difference from the inclination of the straight line changes with respect to the position of the wheel mounting portion.

Therefore, in the second calculation step, based on the difference between the slope of each straight line connecting the second reference coordinate and each set coordinate and the slope of each straight line connecting the first reference coordinate and each measurement coordinate. Then, the estimated value of the toe angle of the position of the wheel mounting portion in the finished vehicle state of the automobile is calculated.

Subsequently, in the third calculation step, an adjustment amount is obtained based on the value obtained in the second calculation step until the correct toe angle of the position of the wheel mounting portion in the completed vehicle state is reached. In this way, the toe angle of the position of the wheel mounting portion in the finished vehicle state can be obtained accurately by calculation without actually setting the wheel mounting portion in the finished vehicle state of the automobile, and the finished vehicle state The amount to be adjusted until the correct toe angle of the position of the wheel mounting portion is obtained can be easily obtained.

In the present invention, it is preferable that the detection of the thrust angle by the thrust angle detection step is performed simultaneously with the measurement of the position of the wheel mounting portion during the ascent and the measurement of the toe angle. Thus, the thrust angle at the time of measuring the toe angle can be detected and the measured toe angle can be corrected, so that a more accurate measured value of the toe angle can be obtained.

Further, the device of the present invention for measuring the toe angle includes a vehicle body support means for supporting the vehicle body by hanging up and down a wheel mounting portion with no wheels mounted thereon, and a lower position of the vehicle body supported by the vehicle body support means. A wheel attachment portion raising means for raising the wheel attachment portion to a predetermined height position, a first measurement means for measuring the height position of the wheel attachment portion provided in the wheel attachment portion raising means, A second measuring means provided on the wheel mounting portion raising means for measuring the toe angle of the axle through the wheel mounting portion and supported in a suspended state with respect to a predetermined center line extending in the vehicle length direction of the vehicle body. A thrust angle detecting means for detecting a lateral angle of a center line extending in the vehicle length direction of the vehicle body as a thrust angle, and the wheel mounting from a position where the wheel mounting section is lifted by the wheel mounting section lifting means. Part Measurement of the height position by the first measurement means, measurement of the toe angle by the second measurement means, and detection of the thrust angle by the thrust angle detection means at predetermined intervals until the height is raised to a predetermined height position. And a position of the wheel mounting portion in the finished vehicle state based on the measurement value of the first measurement means, the measurement value of the second measurement means, and the detection angle of the thrust angle detection means. A toe angle calculating means for calculating a toe angle corresponding to the position of the wheel mounting portion measured at the start of ascent of the wheel mounting portion and the thrust angle detecting means measured at the position. The wheel mounting measured at predetermined intervals until the wheel mounting portion is raised to the predetermined height position, with the coordinates composed of the toe angle corrected based on the detected angle as the first reference coordinates. Position of department And a plurality of coordinates consisting of a toe angle measured at each position and corrected based on the detected angle of the thrust angle detecting means, the inclination of each straight line connecting the first reference coordinate and each measured coordinate is defined as a measurement coordinate. A coordinate composed of first calculation means for calculating, the position of the wheel mounting portion in the first reference coordinate, and a correct toe angle predetermined in correspondence with the position is defined as a second reference coordinate, and each measurement coordinate Each of the straight lines connecting the second reference coordinates calculated in advance and the set coordinates with a plurality of coordinates consisting of each position of the wheel mounting portion and a predetermined correct toe angle corresponding to each position as the set coordinates Second calculation for calculating an estimated value of the toe angle of the position of the wheel mounting portion in the finished vehicle state of the vehicle based on the difference between the slope of the vehicle and the slope of each straight line connecting the first reference coordinate and each measurement coordinate Means and the second computing means And third calculating means for obtaining an amount to be adjusted until the correct toe angle of the position of the wheel mounting portion in the finished vehicle state of the automobile is obtained based on the obtained value .

  When the toe angle is measured by the apparatus of the present invention, the vehicle body support means first supports the vehicle body. At this time, the vehicle body only needs to be supported with the wheel mounting portion being movable up and down. Thus, specifically, for example, a hanger that conveys the vehicle body in the vehicle body assembly line of the automobile can be used as the vehicle body support means.

  Next, the wheel attachment portion raising means raises the wheel attachment portion of the vehicle body supported by the vehicle body support means. Then, the measurement control means measures the height position of the wheel mounting portion by the first measuring means and the toe angle of the wheel mounting portion by the second measuring means when the wheel mounting portion is raised by the wheel mounting portion raising means. And the thrust angle is detected by the thrust angle detecting means.

  Subsequently, the toe angle calculating means has a wheel mounting portion in a finished vehicle state of the automobile based on the measured value by the first measuring means, the measured value by the second measuring means, and the detected angle by the thrust angle detecting means. The toe angle corresponding to the position of is calculated.

  Thus, the toe angle calculating means corrects the toe angle measured by the second measuring means based on the thrust angle detected by the thrust angle detecting means, thereby obtaining a highly accurate measured value of the toe angle. It is possible to accurately calculate the toe angle at the position of the wheel mounting portion in the finished vehicle state of the automobile.

Here, the toe angle calculating means calculates the inclination of each straight line connecting the first reference coordinate and each measurement coordinate, and the inclination of each straight line connecting the second reference coordinate and each set coordinate; Since the estimated value of the toe angle of the position of the wheel mounting portion in the finished vehicle state is calculated based on the difference between the slope of each straight line connecting the reference coordinates of 1 and each measurement coordinate, the wheel mounting portion is actually The toe angle of the position of the wheel mounting portion in the completed vehicle state can be obtained by calculation without setting the position in the completed vehicle state of the automobile. Then, based on the estimated value of the toe angle at this time, an adjustment amount can be obtained until the correct toe angle of the position of the wheel mounting portion in the finished vehicle state of the automobile is obtained, so a load is applied to the vehicle body as in the past. Therefore, the toe angle in the finished vehicle state of the automobile can be measured quickly and accurately with a simple apparatus configuration.

  An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram showing a schematic configuration of a toe angle measuring device of the present embodiment, FIG. 2 is an operation explanatory diagram of a wheel mounting portion raising means, FIG. 3 is an explanatory diagram showing a second measuring means, and FIG. FIG. 5 is a flowchart showing a toe angle measurement method, and FIG. 6 is a diagram showing the relationship between the position of the wheel mounting portion and the toe angle.

  In FIG. 1, reference numeral 1 denotes a hanger that supports an automobile body 2 and conveys the body 2 along an assembly line (not shown). The toe angle measuring device 3 of the present embodiment is provided below the conveyance path of the vehicle body 2 by the hanger 1. The vehicle body 2 conveyed to a position directly above the toe angle measuring device 3 is assembled with a steering device and a suspension device 4 (not shown) in the assembly line, and the steering position of the steering device is adjusted to the neutral position. In addition, the wheel attachment portion 5 provided on the vehicle body 2 via the suspension device 4 is not attached to the wheel, and is hung so as to be able to be raised and lowered by the suspension support of the vehicle body 2 by the hanger 1.

  As shown in FIG. 1, the toe angle measuring device 3 includes a wheel attachment portion raising means 6 for raising the wheel attachment portion 5, a first measurement means 7 for measuring the height position of the wheel attachment portion 5, and the wheel And a second measuring means 8 for measuring the toe angle of the mounting portion 5. The first measurement means 7 and the second measurement means 8 are connected to a measurement control means (not shown) that controls measurement at a plurality of positions described later. Further, the measurement control means is connected to a calculation means which is a toe angle calculation means (not shown), and the calculation means calculates a toe angle from a plurality of measurement values (described later) collected via the measurement control means.

  The wheel mounting part raising means 6 is provided at four locations corresponding to each wheel mounting part 5 of the vehicle body 2, and as shown in FIGS. 1 and 2, a contact member that contacts the wheel mounting part 5 from below. 9, a vertically movable lift plate 10 that integrally supports the contact member 9, and a first cylinder 11 that lifts the wheel mounting portion 5 that is in contact with the contact member 9 via the lift plate 10. ing. The first table 12 on which the first cylinder 11 is provided is provided so as to be movable up and down along a guide rail 14 provided on a support column 13 that is vertically provided. A second table 15 that can be raised and lowered along the guide rail 14 is provided at a position below the first table 12, and a second cylinder 16 that raises and lowers the first table 12 is provided on the second table 15. . Further, the second table 15 is moved up and down by a third cylinder 18 provided in a bracket 17 below the support column 13.

  Further, a rod-shaped member 19 is erected on the second table 15. A sensor 20 is provided at the tip of the rod-like member 19 to detect that the second table 15 is brought into contact with the base end of the suspension device 4 at the bottom of the vehicle body 2. When the sensor 20 detects that the bottom of the vehicle body 2 is in contact with the base end of the suspension device 4, the operation of the third cylinder 18 is stopped and the position of the second table 15 is maintained. It should be noted that the inclination angle in the vehicle width direction of the vehicle body on the hanger 1 can be detected from the stop positions of the four rod-shaped members 19 corresponding to the wheel mounting portions 5 of the vehicle body 2.

  As shown in FIGS. 1 and 2, the first measuring means 7 is a laser sensor provided on the first table 12, and the axis of the wheel mounting portion 5 is measured by measuring the rising distance of the lifting plate 10. Measure the position. Further, as shown in FIG. 3, the second measuring means 8 is constituted by three laser sensors (first sensor 21, second sensor 22, third sensor 23) and is integrally supported by a support member 24. The first cylinder 11 moves up and down. The first sensor 21, the second sensor 22, and the third sensor 23 are opposed to the three points e, f, and g of the wheel mounting portion 5, respectively. The first sensor 21 is a distance E to the point e of the wheel mounting part 5, the second sensor 22 is a distance F to the point f of the wheel mounting part 5, and the third sensor 23 is a point to the point g of the wheel mounting part 5. Each distance G is measured. The horizontal displacement between the point f and the point g is measured from the difference between the distance F measured by the second sensor 22 and the distance G measured by the third sensor 23, and the toe angle is detected from this displacement.

  The first sensor 21, the second sensor 22, and the third sensor 23 of the second measuring means 8 supply the measurement results to a thrust angle detecting means (not shown). That is, the thrust angle detecting means includes a first sensor 21 shown in FIG. 3 that is a distance E to the point e of the wheel mounting portion 5, a second sensor 22 that is a distance F to the point f of the wheel mounting portion 5, and a third sensor 23. Is obtained from (E + F + G) / 3 based on the distance G to the point g of the wheel mounting portion 5 from (E + F + G) / 3, and as shown in FIG. The thrust angle θ of the vehicle body 2 is calculated based on the distances of the four locations corresponding to the part 5. Thus, the right and left directions of the center line B extending in the vehicle length direction of the vehicle body supported in the suspended state with respect to the predetermined correct center line A extending in the vehicle length direction of the vehicle body 2 by the thrust angle detection means. Is detected as the thrust angle θ. The detection of the thrust angle θ by the thrust angle detection means is performed simultaneously with the first measurement means 7 and the second measurement means 8 under the control of the measurement control means.

  Next, the toe angle measuring method according to the present embodiment will be described. As shown in FIG. 1, when the vehicle body 2 supported by the hanger 1 is conveyed immediately above the toe angle measuring device 3, the second table 15 is raised by the third cylinder 18, and the rod-shaped member 19 contacts the vehicle body 2. After that, the wheel mounting portion raising means 6 is brought close to the wheel mounting portion 5 by the second cylinder 16.

  Next, as shown in FIG. 2, the lifting plate 10 is raised by the first cylinder 11, and the contact member 9 comes into contact with the wheel attachment portion 5 (wheel attachment portion raising step). At this time, the axial center position of the wheel mounting portion 5 where the ascent starts is measured by the first measuring means 7 (measuring step). At this time, the wheel mounting portion 5 is in a position depending on the vehicle body 2, and the measured vehicle type of the present embodiment is less than −90 mm with respect to the position (0 mm) of the wheel mounting portion 5 in the completed vehicle state. It is in the lower position.

  Then, the lifting plate 10 is further raised by the first cylinder 11, and the wheel mounting portion 5 is moved until the axial center position of the wheel mounting portion 5 becomes −60 mm with respect to the position of the wheel mounting portion 5 in the completed vehicle state. Be raised. In the present embodiment, the position of −90 mm is the measurement start position, and the position of −60 mm is the toe angle adjustment position.

  On the other hand, when the wheel mounting portion 5 is lifted by the wheel mounting portion lifting means 6, a plurality of positions of the wheel mounting portion 5, toe angles and thrust angles θ corresponding to the respective positions are controlled by the measurement control means. Measured (thrust angle detection step). In the present embodiment, the first measurement indicates that the wheel mounting portion 5 is positioned at −90 mm, −80 mm, −70 mm, and −60 mm with respect to the position of the wheel mounting portion 5 in the completed vehicle state by the control of the measurement control unit. The toe angle and the thrust angle θ at each position are detected by the measurement of the means 7 and measured by the second measuring means 8 and the thrust angle detecting means.

  In the present embodiment, the vehicle body 2 supported by the hanger 1 can move the wheel mounting portion 5 to a position of −60 mm with respect to the position of the wheel mounting portion 5 in the completed vehicle state (30 mm from the −90 mm position). Even if it is raised, it will not lift off the hanger 1. Thus, the maximum ascending position of the wheel mounting portion 5 is set to a position where the state where the vehicle body 2 is not lifted up and is supported by the hanger 1 is reliably maintained, so that the toe angle can be measured in a stable state. Can be done.

  Then, after the wheel mounting portion 5 is lifted by the wheel mounting portion lifting means 6, the position of the wheel mounting portion 5 and the toe angle and thrust angle are measured, and then the calculation means calculates the toe angle based on the thrust angle. The toe angle corresponding to the position of the wheel mounting portion 5 in the completed vehicle state is calculated.

  Subsequently, the tow at the adjustment position (a position of −60 mm with respect to the position of the wheel mounting portion 5 in the completed vehicle state) is calculated by the calculating means based on the toe angle corresponding to the position of the wheel mounting portion 5 in the completed vehicle state. An angle adjustment amount is calculated (toe angle calculation step), and a toe angle adjustment operation at the adjustment position is performed according to the adjustment amount.

Here, calculation of the toe angle corresponding to the position of the wheel mounting portion 5 in the completed vehicle state and calculation of the adjustment amount corresponding to the adjustment position by the calculation means will be described. First, in STEP 1 shown in FIG. 5, the wheel mounting portion 5 is lifted by the wheel mounting portion lifting means 6, and the axial center position (a = −90 mm) of the wheel mounting portion 5 at the measurement start position and the toe on the hanger 1. The angle b ′ and the thrust angle θ are measured, and then on the hanger 1 at predetermined intervals (every 10 mm) until the axial center position of the wheel mounting portion 5 reaches the adjustment position (a = −60 mm). The toe angle b ′ and the thrust angle θ are measured. Further, in STEP 2 shown in FIG. 5, a corrected toe angle b is obtained by reflecting the thrust angle θ on the toe angle b ′ measured at this time (measurement value correcting step). For example, referring to FIG. 4, when the direction of the center line B of the vehicle body 2 (the front direction of the vehicle body) is directed to the right of the correct center line A, the front wheel right side and the rear wheel right side of the vehicle body 2 are attached. For part 5, a corrected toe angle b is obtained from equation (1). In this case, since the direction of the center line B of the vehicle body 2 is shifted to the right of the correct center line A for each of the front wheel left side and the rear wheel left side of the vehicle body 2, correction is made from Equation (2). The toe angle b is determined.
b = b ′ + θ (1)
b = b′−θ (2)
As shown in FIG. 6, first, the coordinates (a, b) of the toe angle b measured and corrected when the axial center position a of the wheel mounting portion 5 is −90 mm are set as the first reference coordinates J. . Further, the coordinates (a, b) of the toe angle b measured and corrected when the axial center position a of the wheel mounting portion 5 is −80 mm are the first measurement coordinates J ₁ , and the axial center position a of the wheel mounting portion 5 is. The toe angle b coordinate (a, b) measured and corrected when the angle is −70 mm is the second measured coordinate J ₂ , and is measured and corrected when the axial center position a of the wheel mounting portion 5 is −60 mm. The coordinate (a, b) of the toe angle b is defined as a third measurement coordinate J ₃ .

Next, as shown in FIG. 6, the slope Δtoe _{j st = −80} of the straight line connecting the first reference coordinate J and the first measurement coordinate J ₁ , the first reference coordinate J and the second measurement coordinate J _2. the slope of the line Δtoe _{j st = -70} connecting bets, the slope of the line Δtoe _{j st = -60} respectively calculates connecting the first reference coordinates J and the third measurement coordinates J ₃ (see STEP3 in FIG. 5) . Hereinafter, the slope calculated at this time is referred to as an actually measured slope (Δtoe _j ).

On the other hand, in the calculating means, the correct change amount of the toe angle associated with the rise of the wheel mounting portion 5 by the wheel mounting portion raising means 6 for each vehicle type is recorded as a basic characteristic curve T shown in FIG. Further, in the basic characteristic curve T, as shown in FIG. 6, the coordinates of the correct toe angle when the axial center position of the wheel mounting portion 5 is −90 mm (measurement start position) are set as the second reference coordinates N, which are the same. Thus, the correct toe angle coordinate when the axial center of the wheel mounting portion 5 is −80 mm is the first set coordinate N ₁ , and the correct toe angle coordinate when the wheel mounting portion 5 is −70 mm is the second set coordinate N ₂ , The coordinate of the correct toe angle when −60 mm is set as the third set coordinate N ₃ . At this time, as shown in FIG. 6, the slope Δtoe _{n st = -80} of the straight line connecting the second reference coordinate N and the first set coordinate N ₁ , the second reference coordinate N and the second set coordinate N the slope of the line Δtoe _{n st = -70} connecting the _2, the second reference coordinates n and the third set coordinates n ₃ and the slope of the line Δtoe _{n st = -60} connecting is calculated in advance, respectively (STEP4 in FIG The result is stored. Hereinafter, the inclination stored in advance is referred to as a basic inclination (Δtoe _n ).

Subsequently, in STEP 5 of FIG. 5, the difference (m) between each measured inclination (Δtoe _j ) and each basic inclination (Δtoe _n ) is calculated.
m _-80 = Δtoe _{n st = -80} -Δtoe _{j st = -80} (3)
m ₋₇₀ = Δtoe _{n st = −70} −Δtoe _{j st = −70} (4)
m _-60 = Δtoe _{n st = -60} −Δtoe _{j st = -60} (5)
As a result, the differences m _-80 , m _-70 , and m _-60 of the respective inclinations are obtained. The inventor has conducted various tests that the difference (m) between each measured inclination (Δtoe _j ) and each basic inclination (Δtoe _n ) at each position of the axis of the wheel mounting portion 5 has a constant amount of change. I know. Based on this, the inclination difference m0 at the axial center position (0 mm) of the wheel mounting portion 5 in the completed vehicle state is estimated from the calculated inclination differences m- ₈₀ , m- ₇₀ , m- ₆₀ . (See STEP 6 in FIG. 5).

Based on the value of m ₀ , the toe angle y (the correct toe in FIG. 6) at the axial center position (0 mm) of the wheel mounting portion 5 in the finished vehicle state is obtained by the equation (6) representing the inclination Δtoe _{j st = 0} . Is calculated (see STEP 7 in FIG. 5).
y = α (x−a) + b (6)
In Equation (6), α is the inclination Δtoe _{j st = 0} at the axial center position x of the wheel mounting portion 5 in the completed vehicle state (α = Δtoe _{n st = 0} + m ₀ ). In addition, the toe angle y of the axial center position (x = 0) of the wheel mounting portion 5 in the completed vehicle state in Expression (6) can be expressed by Expression (7).
y = −αa + b (7)
The toe angle y calculated here indicates the toe angle at the axial center position of the wheel mounting portion 5 in the completed vehicle state. On the other hand, the adjustment position of the toe angle is set to −60 mm from the axial center position of the wheel mounting portion 5 in the completed vehicle state. Therefore, the adjustment amount q is calculated by adding the correction amount y ′ corresponding to the adjustment position to the calculated toe angle y as shown in Equation (8) (see STEP 8 in FIG. 5).
q = y + y ′ = y + ky (8)
The correction amount y ′ can be obtained by multiplying the toe angle y by a correction coefficient k calculated in advance corresponding to the adjustment position for each vehicle type. According to the adjustment amount q thus determined, the toe angle is adjusted at the adjustment position.

  As described above, according to the present embodiment, the wheel mounting portion 5 at the adjustment position (in the present embodiment, a position of −60 mm from the completed vehicle state) can be very quickly performed without applying the same load to the vehicle body as in the completed vehicle state. The toe angle can be measured and adjusted. In addition, the toe angle adjustment amount can be obtained simply by raising the wheel mounting portion 5 to the adjustment position without removing the vehicle body 2 from the hanger 1, so that the toe angle can be efficiently measured and adjusted. Can be improved. Moreover, even if the center line B in the vehicle length direction of the vehicle body 2 suspended by the hanger 1 is shifted from the correct center line A with the thrust angle θ in the left-right direction, the toe angle can be accurately calculated.

  The measurement start position, the adjustment position, and each measurement interval described above are appropriately determined according to the characteristics of the suspension of the vehicle model to be measured, and are limited to the dimensions employed in the toe angle measurement of this embodiment. It is not a thing. Moreover, the accuracy of the adjustment amount can be increased as the measurement interval is set shorter.

An explanatory view showing a schematic configuration of a toe angle measuring device of one embodiment of the present invention, Operation | movement explanatory drawing of a wheel attachment part raising means. Explanatory drawing which shows a 2nd measurement means. An explanatory plan view showing a posture of a vehicle body at the time of measurement. The flowchart which shows the measuring method of a toe angle. The diagram which shows the relationship between the position of a wheel attachment part, and a toe angle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Hanger (body support means), 2 ... Auto body, 3 ... Toe angle measuring device, 5 ... Wheel attachment part, 6 ... Wheel attachment part raising means, 7 ... 1st measurement means, 8 ... 2nd measurement means

Claims (3)

A method for measuring a toe angle of an automobile conveyed in a suspended state in an automobile assembly line,
Maintaining the suspended state of the automobile body, allowing the wheel mounting part with no wheel mounted to be raised and lowered, raising the wheel mounting part to a predetermined height position, and raising by the wheel mounting part raising process A method for measuring a toe angle of an automobile, comprising: a measuring step for measuring a position of a wheel attachment part on the way and a toe angle; and a toe angle calculating step for calculating a toe angle in a finished vehicle state of the automobile from a measurement value obtained by the measuring step In
In the measurement step, the right and left misalignment angles of the center line extending in the vehicle length direction of the vehicle body supported in a suspended state with respect to the correct center line extending in the vehicle length direction of the vehicle body predetermined at the measurement position are thrust. A thrust angle detection step for detecting as an angle, and a measurement value correction step for correcting a measurement value of the toe angle based on the thrust angle detected by the thrust angle detection step,
The toe angle calculation step uses, as a first reference coordinate, a coordinate formed by the position of the wheel mounting portion measured at the start of raising the wheel mounting portion and the toe angle measured at the position and corrected by the measurement value correction step. , The position of the wheel mounting portion measured at predetermined intervals until the wheel mounting portion is raised to the predetermined height position, and the toe angle measured at each position and corrected by the measurement value correcting step. A first calculation step for calculating a slope of each straight line connecting the first reference coordinate and each measurement coordinate, using the plurality of coordinates as measurement coordinates, and a position of the wheel mounting portion in the first reference coordinate and the position The coordinates composed of the correct toe angle predetermined corresponding to the second reference coordinates are used as the second reference coordinates, and the position of the wheel mounting portion at each measurement coordinate and the correct toe angle predetermined for each position are determined. Multiple coordinates Based on the difference between the slope of each straight line connecting the second reference coordinate calculated in advance and each set coordinate as the constant coordinate and the slope of each straight line connecting the first reference coordinate and each measurement coordinate, the vehicle A second calculation step of calculating an estimated value of the toe angle of the position of the wheel mounting portion in the completed vehicle state, and the position of the wheel mounting portion in the completed vehicle state of the vehicle based on the value obtained by the second calculation step And a third calculation step for obtaining an amount to be adjusted until a correct toe angle is obtained .   The method for measuring a toe angle of an automobile according to claim 1, wherein the detection of the thrust angle of the vehicle body in the thrust angle detecting step is performed simultaneously with the measurement of the position of the wheel mounting part in the middle of ascent and the measurement of the toe angle. A device for measuring a toe angle of an automobile conveyed in a suspended state in an automobile assembly line,
Vehicle body support means for hanging and supporting the vehicle body so that the wheel mounting part with no wheels mounted can be raised and lowered;
A wheel mounting portion raising means which is provided at a lower position of the vehicle body supported by the vehicle body supporting means and raises the wheel mounting portion to a predetermined height position;
First measuring means provided in the wheel mounting portion raising means for measuring the height position of the wheel mounting portion;
Second measuring means provided on the wheel mounting portion raising means for measuring the toe angle of the axle through the wheel mounting portion;
A thrust angle detecting means for detecting, as a thrust angle, a deviation angle in a lateral direction of a center line extending in the vehicle length direction of the vehicle body supported in a suspended state with respect to a correct center line extending in the vehicle length direction of a predetermined vehicle body; ,
The height position by the first measuring means is changed at a predetermined interval from the position at which the wheel attachment portion is raised by the wheel attachment portion raising means until the wheel attachment portion is raised to a predetermined height position. Measurement control means for performing measurement and measurement of the toe angle by the second measurement means and detection of the thrust angle by the thrust angle detection means;
Based on the measured value of the first measuring means, the measured value of the second measuring means, and the detected angle of the thrust angle detecting means, a toe angle corresponding to the position of the wheel mounting portion in the finished vehicle state of the automobile is calculated. A toe angle calculating means,
The toe angle calculating means calculates a coordinate consisting of a position of the wheel mounting portion measured at the start of ascent of the wheel mounting portion and a toe angle measured at the position and corrected based on the detected angle of the thrust angle detecting means. The position of the wheel mounting portion measured at predetermined intervals until the wheel mounting portion is raised to the predetermined height position is measured at each position and detected by the thrust angle detecting means. First calculation means for calculating the inclination of each straight line connecting the first reference coordinate and each measurement coordinate using a plurality of coordinates including the toe angle corrected based on the angle as the measurement coordinate; and the first reference The coordinates consisting of the position of the wheel mounting portion in the coordinates and the correct toe angle predetermined in advance corresponding to the position are used as the second reference coordinates, and each position and each position of the wheel mounting portion in the respective measurement coordinates correspond to each position. Predetermined Using a plurality of coordinates including the correct toe angle as set coordinates, the slope of each straight line connecting the second reference coordinate calculated in advance and each set coordinate, and each straight line connecting the first reference coordinate and each measurement coordinate Second calculating means for calculating an estimated value of the toe angle of the position of the wheel mounting portion in the finished vehicle state of the vehicle based on the difference between the inclination of the vehicle and the value of the vehicle based on the value obtained by the second calculating means A toe angle measuring device for an automobile, comprising: third calculating means for obtaining an amount to be adjusted until a correct toe angle of a position of a wheel mounting portion in a completed vehicle state is obtained .

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