Method of measuring a displacement amount for an automobile suspension assembly

Provided is a work measuring method by which a deviation quantity of a work measuring point from a reference position can be measured in a short time. A work surface is set as a reference point when the measuring point is positioned at the reference position, and a distance from a photographing device to a reference surface is set as a reference distance. A deviation quantity of the measurement point in a direction intersecting a photographing direction on the reference surface is measured by the photographing device, and a deviation quantity of the measuring point in the photographing direction is measured by a laser distance sensor. Then, based on the deviation quantity measured by the photographing device, the deviation quantity measured by the laser distance sensor, and the reference distance, a deviation quantity of the measuring point in a direction intersecting the photographing direction is calculated.

TECHNICAL FIELD

The present invention relates to a work measuring method, a method for attaching a suspension assembly, and an apparatus for attaching a suspension assembly.

In detail, it relates to a work measuring method using a photographing device and a laser distance sensor to measure a position of a measurement point of a work such as a suspension assembly relative to the photographing device. In addition, it relates to a method for attaching and an apparatus for attaching a suspension assembly that fixes the suspension assembly to the body of an automobile by bolts.

BACKGROUND ART

Conventionally, in the manufacturing process of automobiles, a suspension assembly has been attached to the body.

The suspension assembly is assembled by connecting the lower end side of a pair of left and right dampers of a front side or rear side with a sub-frame. In addition, a pair of damper housings in which the pair of dampers is accommodated is formed in the body. An upper end side of the pair of dampers is accommodated in each of the pair of damper housings and is supported by attaching such a suspension assembly to the body.

Herein, variability occurs in the position of the body; therefore, it is necessary to measure the displacement amount of the position of the body. Therefore, with a hole formed in the body set as a measurement point, this suspension assembly is attached to the body by measuring the displacement amount from a reference position of this measurement point, and correcting the movement of a robot that has been taught in advance.

Incidentally, although the displacement amount in an in-plane direction of the photographed image, i.e. the displacement amount in a direction intersecting a photographing direction, can be measured with high precision with the special characteristics of a CCD camera, it is difficult to measure the displacement amount in the photographing direction with high precision thereby.

Therefore, in order to measure the distance in the photographing direction with high precision, a laser distance sensor has been provided and the displacement amount in the photographing direction at a measurement point of the body has been measured by this laser distance sensor, after which the focal length of the CCD camera has been corrected based on this displacement amount measured, and the displacement amount in a direction intersecting the photographing direction at the measurement point of the body has been measured by this CCD camera (refer to Patent Document 1).

In addition, high precision has been demanded in attachment of suspension assemblies to bodies because, if the attachment position of the suspension assembly shifts from the reference position, a difference in left and right camber angles arises.

Therefore, a method is shown in Patent Document 2, for example, for suspension assembly positioning in which the object is to improve the attachment precision of the suspension assembly. With this positioning method, the center position of the body and the center position of the suspension assembly are calculated based on a detection signal from a plurality of distance sensors, and the position of the suspension assembly is adjusted so that these center positions match.

After the position of the suspension assembly has been adjusted in the above such way, the suspension assembly is fixed to the body by tightening bolts provided at an upper end side of the pair of dampers.

In addition, the suspension assembly is fixed to the body by tightening bolts of a plurality of locations. In this case, at each tightening locations, a dedicated nut runner (refer to Patent Document 3) is arranged, respectively.

However, if a dedicated nut runner is provided to each tightening location, in a case of tightening a tightening location at a position that differs for each model, displacement will arise between the arrangement locations of the nut runners and the tightening locations of the suspension assembly. In such a case, conventionally, it has been compensated for by providing in advance a jig to correct these positional displacements on a mounting stand for the suspension assembly, and tightening via this jig.

Patent Document 1: Republication of Internal Publication No. WO 97/24206

Patent Document 2: Japanese Unexamined Patent Application Publication No. 2007-69826

Patent Document 3: Japanese Unexamined Patent Application Publication No. 2007-216789

Patent Document 3: Japanese Unexamined Patent Application Publication No. H9-66425

DISCLOSURE OF THE INVENTION

Problems to be Solved by the Invention

However, after measured by the laser distance sensor, time has been required in measurement of the displacement amount of the measurement point of the work since the focal distance of the CCD camera is corrected.

In addition, the suspension assembly is formed by joining a plurality of components such as dampers and a sub-frame, and has a complicated three-dimensional shape. As a result, when tightening the bolts on the upper end side of the dampers in the way described above, the sub-frame may move and the left and right camber angles may shift as a result.

In addition, since the alignment may be negatively influenced if the position relative to the body of the suspension assembly shifts from left and right symmetrical positions, it is necessary to attach with high precision so as to be left and right symmetrical. However, when fixing a plurality of locations with bolts, if the sequence in which the bolts are tightened is not taken into account, the sub-frame of the suspension assembly may rotate, and the attitude relative to the body may shift from a left and right symmetrical position.

In addition, if using the aforementioned such dedicated jig, in a case of there being a plurality of tightening locations at different positions, it is necessary to produce a dedicated jig for each of these tightening locations. In addition, since a dedicated jig must be produced when developing a new model, the cost required for equipment may increase.

The present invention has an object of providing a work measuring method by which a displacement amount of a measurement position of a work from a reference position can be measured in a short time.

In addition, the present invention has an object of providing a method of attaching a suspension assembly by which a suspension assembly can be attached to a body while reducing the difference in the left and right camber angles as much as possible.

Moreover, the present invention has an object of providing a method for attaching a suspension assembly by which the suspension assembly can be attached to the body of an automobile with high precision.

Furthermore, the present invention has an object of providing an apparatus for attaching a suspension assembly that can reduce the cost required for equipment.

Means for Solving the Problems

According to a work measuring method of the present invention, in the work measuring method of measuring a displacement amount of a measurement point (e.g., the measurement point P described later) of a work (e.g., the body10described later) surface from a reference position (e.g., the reference position P1described later) using a photographing device (e.g., the COD camera20described later) and a laser distance sensor (e.g., the laser distance sensor30described later), in a case of the measurement point being positioned at the reference position, the work surface is set as a reference plane (e.g., the reference plane R described later), and a distance from the photographing device to the reference plane is set as a reference distance (e.g., the reference distance Lm described later), a displacement amount (e.g., the displacement amount a described later) of the measurement point in a direction intersecting a photographing direction in the reference plane is measured by the photographing device, and a displacement amount (e.g., the displacement amount Lg described later) of the measurement point in the photographing direction is measured by the laser distance sensor, a displacement amount (e.g., the displacement amount b described later) of the measurement point in a direction intersecting the photographing direction is calculated based on the displacement amount measured by the photographing device, the displacement amount measured by the laser distance sensor, and the reference distance.

According to the present invention, the displacement amount of the measurement point in a direction intersecting the photographing direction in the reference plane is measured by the photographing device, and the displacement amount of the measurement point in the photographing direction is measured by the laser distance sensor. Therefore, the displacement amount of the measurement point in a direction intersecting the photographing direction is calculated based on the displacement amount measured by the photographing device, the displacement amount measured by the laser distance sensor, and the reference distance.

Therefore, since it is not necessary to measure with the photographing device after having measured with the laser distance sensor as is conventionally, the displacement amount of the measurement point of the work from the reference position can be measured in a short time.

According to a method for attaching a suspension assembly of the present invention, the method for attaching a suspension assembly of attaching a suspension assembly (e.g., the suspension assembly20described later), which has a pair of dampers (e.g., the damper assemblies24L and24R described later) and a frame (e.g., the sub-frame21described later) that connects a lower end side of the pair of dampers, to a body of an automobile (e.g., the body10described later) includes: a step of measuring a pair of reference positions (e.g., the positions BL and BR of the damper mounting holes13L and13R described later) provided on the body that are references for an attitude of the body, and calculating a center position (e.g., the position BC described later) of the body; a step of measuring a pair of reference positions (e.g., the positions SL and SR of the sub-frame reference holes26L and26R described later) provided on the suspension assembly that are references for an attitude of the suspension assembly, and calculating a center position (e.g., the position SC described later) of the suspension assembly; and a step of attaching the suspension assembly to the body so that the center position of the body and the center position of the suspension assembly match, in which, in the step of attaching the suspension assembly to the body, the frame of the suspension assembly is fixed to the body, and an upper end side of the pair of dampers (e.g., the damper mounts243L and243R described later) is fixed to a damper housing (the damper housings12L and12R described later) in the body in which the pair of dampers is accommodated.

According to the present invention, the center position of the body and the center position of the suspension assembly are calculated, and the suspension assembly is attached to the body so that this center position of the body and center position of the suspension assembly match. Furthermore, herein, the frame connecting the lower end sides of the pair of dampers are fixed to the body, while the upper end side of the pair of dampers are fixed to the damper housings of the body.

In this way, by fixing the upper end side and lower end side of the pair of dampers in the same process, the sub-frame does not move as conventionally. With this, the suspension assembly can be attached to the body with the difference in the left and right camber angles reduced as much as possible.

According to a method for attaching a suspension assembly of the present invention, the method for attaching a suspension assembly) of fixing the suspension assembly (e.g., the suspension assembly20described later to a body (e.g., the body10described later) of an automobile at a plurality of locations by bolts includes: a step of tightening in pairs tightening locations positioned symmetrically relative to a central axis of the body, among the tightening locations of the suspension assembly; and a step of tightening tightening locations positioned unsymmetrically relative to the central axis of the body, among the tightening locations of the suspension assembly.

According to the present invention, among the plurality of tightening locations in the suspension assembly, the tightening locations positioned symmetrically relative to the central axis of the body are tightened in pairs. Thereafter, the tightening locations positioned unsymmetrically relative to the central axis are tightened. In this way, it is possible to prevent the suspension assembly from rotating relative to the body, and the attitude relating to the body from shifting from a left-right symmetrical position, by tightening the tightening locations positioned symmetrically relative to the central axis of the body in pairs. Therefore, the suspension assembly can be attached to the body with high precision.

According to a method for attaching a suspension assembly of the present invention, the apparatus for attaching a suspension assembly (e.g., the mounting system1) for a plurality of models of automobile that tightens the suspension assembly (e.g., the suspension assembly20) having a pair of dampers (e.g., the damper assemblies24L and24R) to a body (e.g., the body10) by bolts, includes: a robot (e.g., the tightening robots60L,60R,61L, and61R described later) that tightens a tightening location that is common to the plurality of models; and a unique location tightening device (e.g., the unique location tightening units70L,70R,71L, and71R described later) that tightens a unique tightening location to each of the plurality of models, in which the robot includes a robot arm (e.g., the arm63described later), and a nut runner (e.g., the nut runner65described later) that is attached to a tip end of the robot arm, the unique location tightening device includes a nut runner (e.g., the nut runner71described later), an advance/retract mechanism (e.g., the advance/retract mechanism72described later) that causes the nut runner to advance and retract relative to the suspension assembly, and a transfer mechanism (e.g., the transfer mechanism73described later) that supports the advance/retract mechanism to be movable along a plane that intersects with an advance/retract direction, and the robot causes the advance/retract mechanism to move along a plane that intersects with the advance/retract direction by operating the advance/retract mechanism, and causes the nut runner of the unique location tightening device to oppose the unique tightening location.

According to the present invention, since the tightening robot that tightens a tightening location common to a plurality of models and a unique location tightening device that tightens a tightening location unique to each of a plurality of models are provided, the versatility and operation rate of the apparatus for attaching a suspension assembly can be improved. In addition, since it is not necessary to produce a dedicated jig when developing a new model, the cost required for equipment can be reduced.

In addition, when making the nut runner of this unique location tightening device to oppose a unique tightening location, the advance/retract mechanism is manipulated by the robot that tightens a common tightening location, and this advance/retract mechanism is made to move along a plane intersecting the advance/retract direction of this advance/retract mechanism. In other words, since it is not necessary to provide a driving source for causing the advance/retract mechanism to move along the plane intersecting the advance/retract direction in this unique location tightening device, the cost required for equipment can be reduced.

Effects of the Invention

According to the work measuring method of the present invention, the displacement amount of the measurement point in a direction intersecting the photographing direction in the reference plane is measured by the photographing device, and the displacement amount of the measurement point in the photographing direction is measured by the laser distance sensor. Therefore, the displacement amount of the measurement point in a direction intersecting the photographing direction is calculated based on the displacement amount measured by the photographing device, the displacement amount measured by the laser distance sensor, and the reference distance. Therefore, since it is not necessary to measure with the photographing device after having measured with the laser distance sensor as is conventionally, the displacement amount of the measurement point of the work from the reference position can be measured in a short time.

According to the method for attaching a suspension assembly of the present invention, by fixing the upper end side and lower end side of the pair of dampers in the same process, the sub-frame does not move as conventionally. With this, the suspension assembly can be attached to the body with the difference in the left and right camber angles reduced as much as possible.

According to the method for attaching a suspension assembly of the present invention, it is possible to prevent the suspension assembly from rotating relative to the body, and the attitude relating to the body from shifting from a left-right symmetrical position, by tightening the tightening locations positioned symmetrically relative to the central axis of the body in pairs. Therefore, the suspension assembly can be attached to the body with high precision.

According to the apparatus for attaching a suspension assembly of the present invention, the versatility and operation rate of the apparatus for attaching a suspension assembly can be improved. In addition, since it is not necessary to produce a dedicated jig when developing a new model, the cost required for equipment can be reduced. In addition, since it is not necessary to provide a driving source for causing the advance/retract mechanism to move along a plane intersecting the advance/retract direction in this unique location tightening device, the cost required for equipment can be reduced.

EXPLANATION OF REFERENCE NUMERALS

13L,13R damper mounting hole

14L,14R lower frame

3assembly support device

40position sensor system

61robot main body

70L,70R,71L,71R unique location tightening unit (unique location tightening device)

71FL,72FL,73FL, front left tightening location

71FR,72FR,73FR front right tightening location

71RL,72RL,73RL rear left tightening location

71RR,72RR,73RR rear right tightening location

91alignment control portion

92tightening control portion

130laser distance sensor

Lg displacement amount of measurement point in photographing direction

Lm reference distance

P measurement point

R reference plane

a displacement amount of measurement point in direction intersecting photographing direction in reference plane

b displacement amount of measurement point in direction intersecting photographing direction

PREFERRED MODE FOR CARRYING OUT THE INVENTION

Each embodiment of the present invention will be explained hereinafter based on the drawings.

FIG. 1is a side view showing a configuration of a work measuring system101to which a work measuring method according to a first embodiment of the present invention has been applied.

The work measuring system101is a system that measures a position of a body110when attaching the body110of a vehicle as a work to a suspension assembly140.

Damper housings112, and dash board uppers111positioned above these damper housings are formed in the body110.

A mount insertion hole113of circular shape, and a plurality of bolt insertion holes114formed around this mount insertion hole113are formed in the damper housing112.

The suspension assembly140is assembled by connecting the front left and right dampers and the suspension with the sub-frame.

This suspension assembly140includes a damper141of substantially rod shape, 1 spring142provided substantially concentrically in the damper141, and a damper mount143of substantially disk shape provided on a tip end side of the damper141.

A damper cap144is removably provided at the middle of the damper mount143, and a plurality of bolts145are installed upright at the periphery of the damper mount143

The work measuring system101is inserted between the dash board upper111of the body110and the left and right damper housings112, and measures the center of the mount insertion hole113of circular shape formed in the damper housing112as a measurement point P.

Then, the body110is attached to the suspension assembly140so that an end of the damper cap144of the damper mount143passes through this measurement point P.

The work measuring system101includes a CCD camera120as a photographing device, a laser distance sensor130, and a control device131that controls these.

The CCD camera120includes a camera main body121that captures an image, and a mirror unit122that causes incident light to be reflected and emitted towards the camera main body121.

The control device131obtains the measurement point P based on the image captured by the CCD camera120and the distance measured by the laser distance sensor130.

A sequence of measuring displacement of the measurement point P on the damper housing112by way of the above work measuring system101will be explained while referring toFIG. 2.

First, a reference position of the measurement point P is set as P1, and a surface of the damper housing12when the measurement point P is positioned at the reference position P1is set as a reference plane R. This reference plane R is separated from the CCD camera120in the photographing direction only by a reference distance Lm, and the focal point of the CCD camera120is tailored to the reference plane R. Therefore, the displacement amount in an in-plane direction of the measurement point P of the reference plane R in the captured image, i.e. the displacement amount in a direction intersecting the photographing direction, becomes measurable with high precision by this CCD camera120.

The body110that is the work is conveyed, and the measurement point P of this body110is positioned at a position P2shifted from the reference position P1.

First, the COD camera120and the laser distance sensor130are transferred to a position opposing the reference position P1of the measurement point P of the damper housing112.

Next, the damper housing112is photographed by the CCD camera120, the profile of the mount insertion hole113is recognized by the control device131based on this image thus captured, and the center of the profile of this mount insertion hole113is obtained as the actual position P2of the measurement point P. Then, the actual position P2thus obtained and the reference position P1stored in advance are compared, and a displacement amount a in the reference plane R of the measurement point P in a direction intersecting the photographing direction is measured. Simultaneously, the distance to the surface of the damper housing112is measured by the laser distance sensor130, and is set as a displacement amount Lg of the measurement point P in the photographing direction.

Next, a displacement amount b of the measurement point P in a direction intersecting the photographing direction is calculated by the control device131based on the displacement amount a measured by the CCD camera120, the displacement amount Lg measured by the laser distance sensor130, and the reference distance Lm.

More specifically, it is calculated based on the following formula (1).
b=a(Lm+Lg)/Lm(1)

According to the present invention, there are the following effects.

(1) The displacement amount a of the measurement point P in a direction intersecting the photographing direction in the reference plane R is measured by the CCD camera120, and the displacement amount Lg of the measurement point P in the photographing direction is measured by the laser distance sensor130. Then, the displacement amount b of the measurement point P in a direction intersecting the photographing direction is calculated based on the displacement amount a measured by the COD camera120, the displacement amount Lg measured by the laser distance sensor130, and the reference distance Lm.

Therefore, since it is not necessary to measure with the CCD camera120after having measured with the laser distance sensor130as is conventionally, the displacement amount of the measurement point P of the body110from the reference position P1can be measured in a short time.

FIG. 3is a block diagram showing a configuration of a mounting system1of a suspension assembly as an apparatus for attaching a suspension assembly according to a second embodiment of the present invention. The method for attaching a suspension assembly is performed with this mounting system1.

The mounting system1attaches the suspension assembly20at a predetermined position of the body10of an automobile, and is provided at a part of the production line of the automobile.

The mounting system1is configured to include a body conveying apparatus2that conveys the bodies10, an assembly support device3that supports the suspension assembly20, a position sensor system40that detects a position of the body10and the suspension assembly20, a tightening system50that fixes the body10and the suspension assembly20by bolts, and a control device90that controls these.

FIG. 4is a schematic diagram showing a configuration of the body10and the suspension assembly20.

The suspension assembly20configures the undercarriage of the automobile, and is configured to include a front suspension assembly to which a pair of front wheels is attached, and a rear suspension assembly to which a pair or rear wheels is attached.FIG. 4shows the front face of such a suspension assembly20, i.e. only a configuration of a front side.

The suspension assembly20is configured by joining a plurality of components in general left-right symmetry with the sub-frame21as a base. A pair of lower arms22L and22R, hubs23L and23R, and damper assemblies24L and24R are attached to both left and right sides of the sub-frame21, and an engine, which is not illustrated, is attached to substantially the center of the sub-frame21. A pair of front wheels, which are not illustrated, is attached in a subsequent process to the hubs23L and23R.

In addition, sub-frame reference holes26L and26R formed in left-right symmetry relative to the center of the suspension assembly20are formed in the bottom of the sub-frame21. These sub-frame reference holes26L and26R become references for the attitude of the suspension assembly20.

The pair of damper assemblies24L and24R respectively include dampers241L and241R of substantially rod shape, springs242L and242R provided substantially concentrically to the dampers241L and241R, and damper mounts243L and243R configuring an upper end side of the damper assemblies24L and24R. The lower end side of the damper assemblies24L and24R are respectively connected to both end sides of the sub-frame21via each of the lower arms22L and22R.

A plurality of bolt portions244L and245L that extend substantially in parallel to the damper241L is installed upright in the damper mount243L. Similarly, a plurality of bolt portions244R and245R that extend substantially in parallel to the damper241R is installed upright in the damper mount243R.

In addition, damper caps246L and246R are detachably provided at the middle of the damper mounts243L and243R. These damper caps246L and246R are each formed in a cone shape, and become a guide portion when inserting into the damper mounting holes13L and13R described later.

In addition, although drawings and a detailed explanation thereof are omitted, a pair of damper assemblies is similarly provided in left-right symmetry also at the rear side of the suspension assembly20.

The body10is an underpinning frame configuring an automobile, and a pair of damper housings12L and12R in which a pair of damper assemblies24L and24R is accommodated is formed at both left and right sides of the engine compartment11in which the engine is accommodated.

The damper mounting hole13L and bolt insertion holes15L and16L in which the damper cap246L and bolt portions244L and245L of the damper assembly24L are respectively inserted are formed in the damper housing12L. Similarly, the damper mounting hole13R and bolt insertion holes15R and16R in which the damper cap246R and bolt portions244R and245R of the damper assembly24R are respectively inserted are formed in the damper housing12R. These damper mounting holes13L and13R, bolt insertion holes15L and15R, and bolt insertion holes16L and16R are formed in left-right symmetry relative to the center of the body10. In particular, the damper mounting holes13L and13R become references for the attitude of the body10.

This body10is conveyed above the suspension assembly20in a state of being suspended on a hanger of the body conveying apparatus (not illustrated).

FIG. 5is a perspective view showing a configuration of the assembly support device3.

The assembly support device3is configured to include a parent pallet33of a substantially board shape, and two child pallets31and32that are supported from underneath by this parent pallet33.

A plurality of fixing pins331and332for fixing the child pallet31of a front side and a plurality of fixing pins333and334for fixing the child pallet32of a rear side are respectively formed at the front end side and read end side of the parent pallet33.

The child pallets31and32respectively support the front side and rear side of the suspension assembly, and have formed therein fitting holes311,312and fitting holes321,322in which the aforementioned fixing pins331,332and fixing pins333,334fit. These child pallets31and32are each fixed to the parent pallet33in a state in which the front side and rear side of the suspension assembly are placed thereon.

In such an assembly support device3, it is preferable to use a feature that is dedicated to each model in the child pallets31and32, and to use a feature that is common to each model in the parent pallet33. In this case, since only the child pallets may be exchanged when changing the model, the cost required in production of the assembly support device can be reduced.

Referring again toFIG. 4, the child pallet31is configured to include a slide rail313that extends along a width direction of the automobile, and a table315in which a slide guide314that slidingly contacts along this slide rail313. In addition, the suspension assembly20is placed on the table315. With this, it becomes possible to slidingly move the table315along the width direction of the automobile along with the suspension assembly20.

In addition, the child pallet31further includes a cylinder317that causes a piston rod316of rod shape to advance and retract along the slide rail313, and is made to stop at a predetermined position. A tip end portion of this piston rod316is connected to the table315, which allows for control of the position of the table315and the suspension assembly20along the width direction of the automobile. This cylinder317is coupled to a control device, and moves based on a control signal from this control device.

Referring again toFIG. 3, the position sensor system40is configured to include a pair of body-side sensing robots41L and41R that detect positions which are references for the attitude of the body10, and a pair of suspension-side sensing robots42L and42R that detect positions which are references for the attitude of the suspension assembly. This position sensor system40is connected to a control device90, and detection signals of these body-side sensing robots41L and41R and suspension-side sensing robots42L and42R are supplied to the control device90. The detailed configurations of these sensing robots41L,41R,42L, and42R will be described in detail while referring toFIG. 8hereinafter.

The tightening system50is configured to include a plurality of tightening robots60L,60R,61L, and61R that fix the body10and the suspension assembly20by bolts, and unique location tightening units70L,70R,71L, and71R that are provided to pair with these tightening robots60L,60R,61L, and61R, respectively. This tightening system50is connected to the control device90, and the tightening robots60L,60R,61L, and61R and unique location tightening units70L,70R,71L, and71R move based on control signals from this control device90.

In addition, these tightening robots60L,60R,61L, and61R are each provided in the vicinity of the suspension assembly20, and fix the tightening locations of the front left, front right, rear left, and rear right of the body10and the suspension assembly20by bolts (refer toFIG. 11described later).

Referring toFIGS. 6 and 7, the configurations of the tightening robot60L and the unique location tightening unit70L will be explained in detail.

FIG. 6is a perspective view showing the configuration of the tightening robot60L.

FIG. 7is a perspective view showing the configuration of the unique location tightening unit70L. It should be noted that the configurations of the other tightening robots60R,61L, and61R and the other unique location tightening units70R,71L, and71R are substantially the same as that of the tightening robot60L and the unique location tightening unit70L, and thus drawings and explanations thereof are omitted.

As shown inFIG. 6, the tightening robot60L includes a robot main body61that is attached to a floor surface, and a manipulator62that is provided to this robot main body61. The manipulator62is 7-axis, and includes an articulated arm63that is pivotally supported to the robot main body61, and a nut runner unit64that is pivotally supported to an end flange surface639of this arm63.

The arm63includes a first arm portion631, second arm portion632, third arm portion633, fourth arm portion634, fifth arm portion635, and sixth arm portion636in order from a side of the robot main body61.

The first arm portion631extends substantially linearly, and is pivotally supported to the robot main body61. In the robot main body61, the first arm portion631is made to rotate with an axis extending in a substantially vertical direction as a center of rotation.

The second arm portion632extends substantially linearly, and is pivotally supported to the first arm portion631. In the first arm portion631, the second arm portion632is made to rotate by a drive mechanism, which is not illustrated, with a direction intersecting an extending direction of the first arm portion631as a center of rotation. With this, the angle formed between the extending direction of the first arm portion631and the extending direction of the second arm portion632changes.

The third arm portion633extends substantially linearly, and is pivotally supported to the second arm portion632. In the second arm portion632, the third arm portion633is made to rotate by a drive mechanism, which is not illustrated, with the extending direction of the second arm portion632as a center of rotation.

The fourth arm portion634extends substantially linearly, and is pivotally supported to the third arm portion633. In the third arm portion633, the fourth arm portion634is made to rotate by a drive mechanism, which is not illustrated, with a direction intersecting the extending direction of the third arm portion633as a center of rotation. With this, the angle formed between the extending direction of the third arm portion633and the extending direction of the fourth arm portion634changes.

The fifth arm portion635extends substantially linearly, and is pivotally supported to the fourth arm portion634. In the fourth arm portion634, the fifth arm portion635is made to rotate by a drive mechanism, which is not illustrated, with the extending direction of the fourth arm portion634as a center of rotation.

The sixth arm portion636extends substantially linearly, and is pivotally supported to the fifth arm portion635. In the fifth arm portion635, the sixth arm portion636is made to rotate by a drive mechanism, which is not illustrated, with a direction intersecting the extending direction of the fifth arm portion635as a center of rotation. With this, the angle formed between the extending direction of the fifth arm portion635and the extending direction of the sixth arm portion636changes.

In addition, a tip end side of the sixth arm portion636is the aforementioned end flange surface639, and the nut runner unit64is pivotally supported thereby. In this sixth arm portion636, the nut runner unit64is made to rotate by a drive mechanism, which is not illustrated, with an axis extending in an extending direction of the sixth arm portion636as a center of rotation.

The nut runner unit64includes a nut runner65and a clamp unit provided to a base end side of this nut runner65.

The nut runner65is configured by a drive unit68and a tightening unit66as separate bodies.

The drive unit68is configured to include a socket drive shaft681that extends substantially linearly, a drive motor682that rotates this socket drive shaft681via a transfer mechanism, which is not illustrated, and a housing case683that accommodates this socket drive shaft681and drive motor682. Three tightening tools661,662, and663described later are made to be connectable to the tip end side of this socket drive shaft681.

The tightening unit66includes the three tightening tools661,662, and663of substantially rod shape, a tightening tool switching device664of substantially cylindrical shape that supports these tightening tools661,662, and663to be parallel with a socket drive shaft652, and a sensor unit665that measures the position of an object such as a tightening location.

The tightening tools661,662, and663respectively support sockets667,668, and669of substantially rod shape to be rotatable. The sockets667,668, and669are made to be able to hold a bolt in the tip end portion thereof. In addition, the sockets667,668, and669can be rotationally driven by connecting the tightening tools661,662, and663to the socket drive shaft681.

The tightening tool switching device664is configured to include a drum portion664aof cylindrical shape and a motor that is not illustrated which rotationally drives this drum portion664a. The tightening tools661,662, and663are provided at predetermined intervals on the peripheral surface of the drum portion664a. In other words, the drum portion664arotates to arrange any of the tightening tools661,662, and663coaxially with the socket drive shaft681, whereby it becomes possible to connect to the socket drive shaft681.

The sensor unit665is configured to include a CCD camera and a distance sensor. The CCD sensor of the sensor unit665detects a position of a tightening location within a two-dimensional level plane. In addition, the distance sensor of the sensor unit665measures the distance from the light source to the target by emitting a laser beam on a target and detecting the reflected light thereof. With this, a position of a tightening location within three-dimensional space is measured.

The clamp unit67includes two chuck portions671and672that extend substantially linearly, and thus it is made possible to grip a bolt and manipulate a tool, jig, etc. by way of these chuck portions671and672.

The above such tightening robot60L operates as follows.

First, a bolt is supplied to the tip end portion of each of the sockets667,668, and669by a supply device, which is not illustrated.

Next, the tightening tool switching device664is controlled to connect any of the three tightening tools661,662, and663to the socket drive shaft681, while the position and attitude of the nut runner unit64are controlled based on an input from the sensor unit665, and the tightening unit66is made to face a predetermined tightening location.

Then, the drive motor682is controlled to rotationally drive the socket of the tightening tool that is connected, whereby the predetermined tightening location is fixed by a bolt.

In addition, in a case of successively fixing a plurality of tightening locations by bolts, the tightening tool switching device664is controlled to switch the tightening tool connecting to the socket drive shaft681, while the tightening unit66is made to face a predetermined tightening location, and this tightening location is fixed by a bolt.

As shown inFIG. 7, the unique location tightening unit70L is configured to include a nut runner71provided below the suspension assembly, an advance/retract mechanism72that advances and retracts this nut runner71relative to the suspension assembly, and a transfer mechanism73that supports this advance/retract mechanism72to be movable along with the nut runner71along a plane intersecting an advance/retract direction.

The nut runner71includes a socket711of substantially rod shape, and a drive unit712that rotates this socket711. The socket711is made to be able to retain a bolt in a tip end side thereof. The drive unit712is equipped with a drive motor that rotates the socket711.

The advance/retract mechanism72is configured to include a table721, a nut runner support portion722that is provided to this table and supports the nut runner71to be slidable in a vertical direction, and an pneumatic cylinder723that moves the nut runner71in the vertical direction.

The table721is disposed on the cross-linear guide74of the transfer mechanism73described later, and is made to be able to move within a horizontal plane. In addition, a gripping portion724of substantially rod shape is provided in this table721. The nut runner support portion722includes a support rod725that extends in the vertical direction, and a mounting portion726provided to this support rod725to be slidable in the vertical direction.

The nut runner71is mounted to one end side of this mounting portion726in a state in which the socket711is pointing upward.

The pneumatic cylinder723can advance and retract the shaft727thereof in the vertical direction. A tip end side of this shaft727is connected to the mounting portion726of the nut runner support portion722. In other words, the nut runner71can be made to move in the vertical direction by driving this pneumatic cylinder723to cause the shaft727to advance or retract.

The transfer mechanism73is configured to include the cross-linear guide74that supports the table721to be slidable in a horizontal plane, and a lock mechanism75that locks movement of this cross-linear guide74and the table721.

The cross-linear guide74is configured by combining two of a first linear guide741and a second linear guide743to be orthogonal to each other.

The first linear guide741includes a first slide rail742of substantially linear shape. On the other hand, a slide guide that is not illustrated, which slides in this first slide rail742, is formed in the second linear guide743. Therefore, the second linear guide743is supported by the first linear guide741to be slidable along the first slide rail742.

The second linear guide743includes a second slide rail744of substantially linear shape. On the other hand, a slide guide728that is not illustrated, which slides in this second slide rail744, is formed in the aforementioned table721. Therefore, the table721is supported by the second linear guide743to be slidable along the second slide rail744. In addition, this second linear guide743is provided to the first slide rail742so that the second slide rail744and the first slide rail742are orthogonal.

The lock mechanism75is configured to include a first lock mechanism751that locks the sliding motion of the second linear guide743along the first slide rail742, and a second lock mechanism755that locks movement of the table721along the second slide rail744.

The first lock mechanism751is configured to include a lock cylinder752of rod shape that is fixed to a side portion of the second linear guide743, and a pair of holding portions753and754provided at both end sides of this lock cylinder752.

The lock cylinder752includes at both end sides thereof a pair of piston rods that can advance and retract along a direction perpendicular to the first slide rail742. With this, the holding portions753and754can be brought together to hold the first slide rail742, and can lock sliding motion of the second guide743along the first slide rail742. This lock cylinder752is coupled to a control device, and moves based on a control signal from this control device.

The second lock mechanism755is configured to include a lock cylinder756of rod shape that is fixed to a side portion of the table721, and a pair of holding portions757and758provided at both end sides of this lock cylinder756.

The lock cylinder756includes at both end sides thereof a pair of piston rods that can advance and retract along a direction perpendicular to the second slide rail744. With this, the holding portions757and758can be brought together to hold the second slide rail744, and can lock sliding motion of the table721along the second slide rail744. This lock cylinder756is coupled to a control device, and moves based on a control signal from this control device.

The above such unique location tightening unit70L operates as follows.

First, one among a plurality of bolts accommodated in a bolt accommodating device, which is not illustrated, is picked by the chuck portions671and672of the clamp unit67of the aforementioned tightening robot, and this bolt79is supplied to a tip end portion of the socket711of the nut runner71. In addition, the locks of the first lock mechanism751and the second lock mechanism755are released.

Next, by operating the gripping portion724by way of the chuck portions671and672of the clamp unit67of the tightening robot, the table721is made to move within a horizontal plane, the nut runner71is made to oppose a predetermined tightening location of the suspension assembly, and the first lock mechanism751and second lock mechanism755are controlled to lock the nut runner71at a position opposing the predetermined tightening location.

Next, the pneumatic cylinder723is controlled to cause the nut runner71to approach to a side of the predetermined tightening location.

Then, the nut runner71is controlled to fix this tightening location by a bolt.

In a case of fixing the body and the suspension assembly by bolts at a plurality of tightening locations, it is preferable to use the tightening robot60L and the unique location tightening unit70L for different purposed depending on the type of tightening location.

In other words, in a case of fixing the suspension assembly to the body, although a plurality of tightening locations are fixed by bolts, this plurality of tightening locations is divided into tightening locations common to a plurality of models and unique tightening locations to each of a plurality of models.

In this case, it is preferable for the common tightening locations to be fixed by bolts by way of the tightening robot60L based on movement taught in advance, and for the unique tightening locations to be fixed by bolts by way of the unique location tightening unit70L.

Referring again toFIG. 3, the control device90includes an input circuit having functions such as shaping input signal waveforms from every type of sensor, correcting voltage levels to predetermined levels, and converting analog signal values to digital signal values, and a central processing unit (hereinafter referred to as “CPU”). In addition, the control device90includes a memory circuit that stores various operational programs executed by the CPU, calculation results, and the like, and an output circuit that outputs control signals to the aforementioned body conveying apparatus2, assembly support device3, position sensor system40, tightening system50, and the like. Moreover, the control device90includes a plurality of control blocks that functions according to the configuration of hardware such as the input circuit, CPU, memory circuit, and output circuit. More specifically, the control device90includes an alignment control portion91and a tightening control portion92.

The alignment control portion91calculates center positions of the body10and the suspension assembly20based on input from the position sensor system40, controls the body conveying apparatus2and the assembly support device3depending on displacement of these center positions, and aligns this body10and suspension assembly20at a predetermined attachment position while correcting the relative positions of the body10and suspension assembly20. A sequence of this alignment will be described in detail while referring toFIGS. 8 to 10hereinafter.

After the tightening control portion92has aligned the body10and the suspension assembly20, it controls the tightening robots60L,60R,61L, and61R of the tightening system50to fix a predetermined plurality of tightening locations by bolts in a predetermined tightening order. This tightening order will be described in detail while referring toFIG. 11hereinafter.

Referring toFIGS. 8 to 10, a sequence of attaching the suspension assembly20to the body10will be explained.

The sequence of attaching the suspension assembly20to the body10is configured to include a center calculating process of calculating center positions of the suspension assembly20and the body10, an alignment process of aligning the suspension assembly20and the body10while correcting displacement from the center, and a tightening process of fixing the suspension assembly20and the body10with bolts.

FIG. 8is a schematic diagram showing the center calculating process,FIG. 9is a schematic diagram showing the alignment process, andFIG. 10is a schematic diagram showing the tightening process.

The body-side sensing robots41L and41R are so-called articulated robots, and respectively include sensor units43L and43R that measure a position of the damper mounting holes13L and13R, articulated arms44L and44R that make the attitude and position in three-dimensional space of the sensor units43L and43R change, and sensing robot main bodies45L and45R that support the articulated arms44L and44R.

The sensor units43L and43R are each configured to include a CCD camera and a distance sensor. The CCD cameras of the sensor units43L and43R each detect a position of the damper mounting holes13L and13R within a two-dimensional level plane. In addition, the distance sensors of the sensor units43L and43R each measure a distance from each light source to the damper mounting holes13L and13R by emitting laser beams on the damper mounting holes13L and13R and detecting the reflected light thereof. With this, the sensor units43L and43R measure positions of the damper mounting holes13L and13R in the body10within three-dimensional space. These sensor units43L and43R output information relating to the positions of the damper mounting holes13L and13R detected by each to the control device90.

The suspension-side sensing robots42L and42R are so-called articulated robots, and respectively include the sensor units46L and46R that measure the positions of the sub-frame reference holes26L and26R, articulated arms (not illustrated) that make the attitudes and positions in three-dimensional space of the sensor units46L and46R change, and sensing robot main bodies (not illustrated) that support the articulated arms.

The sensor units46L and46R are each configured to include a CCD camera and a distance sensor. The CCD cameras of the sensor units46L and46R each detect a position of the sub-frame reference holes26L and26R within a two-dimensional level plane. In addition, the distance sensors of the sensor units46L and46R each measure a distance from each light source to the sub-frame reference holes26L and26R by emitting laser beams on the sub-frame reference holes26L and26R and detecting the reflected light thereof. With this, the sensor units46L and46R measure the positions of the sub-frame reference holes26L and26R in the suspension assembly20within three-dimensional space. These sensor units46L and46R output information relating to the positions of the sub-frame reference holes26L and26R detected by each to the control device.

As shown inFIG. 8, in the center calculating step, first, positions BL and BR of the damper mounting holes13L and13R in the body10within three-dimensional space are measured by the body-side sensing robots41L and41R, and a center position BC of the body10is calculated based on these positions BL and BR thus measured. In addition, at the same time, positions SL and SR of the sub-frame reference holes26L and26R in the suspension assembly20within three-dimensional space are measured by the suspension-side sensing robots42L and42R, and a center position SC of the suspension assembly20is calculated based on these positions SL and SR thus measured.

Next, displacement AC between the center position BC of the body10and the center position SC of the suspension assembly is calculated.

As shown inFIG. 9, in the alignment process, while the body conveying apparatus is being controlled to lower the body10, the cylinder317is driven to move the table315of the child pallet31along a width direction along with the suspension assembly20so as to minimize the displacement AC between the body10and the suspension assembly20. With this, the suspension assembly20is made to align with the body10so that the center position BC of the body10and the center position SC of the suspension assembly20match.

Herein, when the body10is lowered while the center position BC of the body10and the center position SC of the suspension assembly20are being made to match, first, the damper caps246L and246R are inserted into the damper mounting holes13L and13R while being guided to the center of these damper mounting holes13L and13R. When the body10is further lowered, the bolt portions244L and245L and the bolt portions244R and245R are inserted into the bolt insertion holes15L and16L and the bolt insertion holes15R and16R.

As shown inFIG. 10, in the tightening process, the suspension assembly20is attached to the body10by fixing with bolts at the predetermined tightening locations in the body10and the suspension assembly20that have been aligned

More specifically, the tightening system is controlled to fasten the bolt portions244L and245L that have been inserted in the bolt insertion holes15L and16L of the damper housing12L and the bolt portions244R and245R that have been inserted in the bolt insertion holes15R and16R of the damper housing12R by nuts, and fixes the damper mounts243L and243R of an upper end side of the damper assemblies24L and24R with the damper housings12L and12R with bolts. In addition, at this time, the lower frames14L and14R of a lower end side of the body10and the sub-frame21are fixed with bolts at sub-frame-side tightening locations29L and29R.

Referring toFIG. 11, the tightening order of a plurality of bolts when fixing the suspension assembly to the body10will be explained.

FIG. 11is a bottom view of the body10.

As shown inFIG. 11, the body10is a substantially rectangular shape. The body10is fixed to the suspension assembly by fixing a plurality of tightening locations with bolts. In order to fix such a plurality of tightening locations with bolts, a plurality of the tightening robots60L,60R,61L, and61R are disposed in the vicinity of the body10. These tightening robots60L,60R,61L, and61R respectively fix each tightening location of the front left, front right, rear left, and rear right of the body10with bolts in a predetermined order.

In the present embodiment, in a case of tightening a plurality of bolts, symmetrical tightening locations relative to a central axis extending along the front-back direction of the body10are tightened as shown by the plurality of white circles inFIG. 11, and then the remaining unsymmetrical tightening locations (not illustrated) relative to the central axis are tightened.

InFIG. 11, among the plurality of tightening locations, only the tightening locations that are at symmetrical positions relative to the central axis of the body10extending along the front-back direction of the automobile are shown. The numerals “1”, “2”, and “3” inside these white circles each indicate the tightening order. The tightening locations71FL,72FL, and73FL of the front left are symmetrical relative to the central axis with the tightening locations71FR,72FR, and73FR of the front right, respectively.

The tightening locations71RL,72RL, and73RL of the rear left are symmetrical relative to the central axis with the tightening locations71RR,72RR, and73RR of the rear right, respectively.

Therefore, when tightening the symmetrical tightening locations relative to the central axis, for the front, first the pair of tightening locations71FL and71FR is tightened, then the pair of tightening locations72FL and72FR is tightened, after which the pair of tightening locations73FL and73FR is tightened, by the tightening robots60L and60R, respectively. With this, tightening for the front can be performed in a left-right symmetrical order about the central axis.

On the other hand, for the rear, first the pair of tightening locations71RL and71RR is tightened, then the pair of tightening locations72RL and72RR is tightened, after which the pair of tightening locations73RL and73RR is tightened, by the tightening robots61L and61R, respectively. With this, tightening for the rear can be performed in a left-right symmetrical order about the central axis.

Herein, it is particularly preferable for tightening for the front and rear to be performed substantially simultaneously.

After having fixed the left-right symmetrical tightening locations with bolts in the above way, the remaining unsymmetrical tightening locations relative to the central axis of the body10are tightened in a predetermined order. With this, the suspension assembly is fixed to the body10.

In the above way, the suspension assembly is fixed to the body10.

According to the present embodiment, there are the following functional effects.

(2) The center position BC of the body10and the center position SC of the suspension assembly20are calculated, and the suspension assembly20is attached to the body10so that this center position BC of the body10and center position SC of the suspension assembly20match. Furthermore, herein, the sub-frame21connecting the lower end sides of the pair of damper assemblies24L and24R are fixed to the lower frames14L and14R of the body10, while the damper mounts243L and243R of the upper end side of the pair of damper assemblies24L and24R are fixed to the damper housings12L and12R of the body10. In this way, by fixing the upper end side and lower end side of the pair of damper assemblies24L and24R in the same process, the sub-frame21does not move as conventionally.

With this, the suspension assembly20can be attached to the body10with the difference in the left and right camber angles reduced as much as possible.

(3) Among the plurality of tightening locations in the suspension assembly20, the tightening locations positioned symmetrically relative to the central axis of the body10are tightened in pairs. Thereafter, the tightening locations positioned unsymmetrically relative to the central axis are tightened. In this way, it is possible to prevent the suspension assembly20from rotating relative to the body10, and the attitude relating to the body10from shifting from a left-right symmetrical position, by tightening the tightening locations positioned symmetrically relative to the central axis of the body10in pairs. Therefore, the suspension assembly20can be attached to the body10with high precision.

(4) Since the plurality of tightening robots60L,60R,61L, and61R that tighten tightening locations common to a plurality of models and a plurality of unique location tightening units70L,70R,71L, and71R that tighten tightening locations unique to each of a plurality of models are provided, the versatility and operation rate of the mounting system1can be improved. In addition, since it is not necessary to produce a dedicated tool when developing a new model, the cost required for equipment can be reduced.

In addition, when making the nut runner71of these unique location tightening units70L,70R,71L, and71R to oppose a unique tightening location, the gripping portion724of the advance/retract mechanism72is manipulated by the tightening robots60L,60R,61L, and61R that tighten common tightening locations, and this advance/retract mechanism72is made to move along a horizontal plane. In other words, since it is not necessary to provide a driving source for causing the advance/retract mechanism72to move along a horizontal plane in these unique location tightening units70L,70R,71L, and71R, the cost required for equipment can be reduced.

It should be noted that the present invention is not to be limited to the embodiments, and modifications, improvements, etc. within a scope that can achieve the object of the present invention are included in the present invention.

For example, although the body10was lowered when attaching the suspension assembly20to the body10in the second embodiment, it is not limited thereto. For example, the suspension assembly may be raised when attaching the suspension assembly to the body.