JPH05246203A - Automatic installation of wheel for automobile - Google Patents

Abstract

PURPOSE:To save time and labor for removing a fitting-up nut for temporarily tightening the brake drum of a rear drum brake. CONSTITUTION:When positions of hub bolts B1-B4 are detected by picking-up an image of a brake drum D1 by using a CCD camera 19, a position of a fitting-up nut N mounted on either one of the hub bolts B is detected at the same time. After removing the fitting-up nut N by using either one of nut runners 18 of hands 16 held by wheel attaching robots 10 and after collecting it in a collecting device 13, the wheel W of a wheel supplying device 12 is held and mounted on the brake drum D1 by using the hand 16 and the brake drum D1 and the wheel W are clamped together and fixed by clamping a wheel nut.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for automatically mounting wheels by a wheel mounting robot in an automobile assembly line.

[0002]

2. Description of the Related Art In an automobile assembly line, as one of automating the assembly of a vehicle body, a wheel mounting robot is used to automatically mount wheels to front and rear acruss. In this conventional wheel automatic attachment method, a visual sensor such as a CCD camera is attached to a hand of a wheel attaching robot, and the visual sensor detects the positions of a plurality of hub bolts of an axle hub to which the wheel is attached, and the hand is attached. The posture of the wheel gripped by is corrected based on the position information of the hub bolt so that the position of the bolt hole of the wheel matches the position of the hub bolt, and then the wheel is mounted on the axle hub. The wheel nut is fastened to the hub bolt by a plurality of nut runners attached to the hand to fix the wheel to the axle hub (a similar technique is disclosed in, for example, Japanese Patent Laid-Open No. 63-134384). Exist).

On the other hand, some automobiles have a rear disc brake specification in which a disc brake is adopted as a rear brake and a rear drum brake specification in which a drum brake is adopted as a rear brake. In the so-called mixed flow assembling line, the vehicle body with the rear disc brake specifications and the vehicle body with the rear drum brake specifications flow in a mixed manner.

Unlike the disc brake, the above-mentioned drum brake has a structure in which the brake drum is fixed together with the road wheel of the wheel by being fastened together by a wheel nut. There is nothing that restrains the brake drum until is installed, and the brake drum is not stable during transportation while flowing through the line.

Therefore, conventionally, for example, as shown in FIG. 7, the brake drum D1 is attached to the axle hub of the rear axle.
Once assembled, a temporary tightening nut N is attached to at least one of the plurality of hub bolts B1 to B4 to temporarily tighten the brake drum D1, before the wheel mounting process by the wheel mounting robot described above. In the process, the worker uses the air impact wrench T or the like to remove the temporary tightening nut N.

[0006]

In the conventional wheel mounting method as described above, it is necessary for the operator to determine whether or not the vehicle body has the rear drum brake specification and then remove the temporary tightening nut N each time. Labor saving cannot be achieved. Further, if the operator neglects the attention, the operator may forget to remove the temporary tightening nut N, which causes a trouble in the wheel mounting process.

The present invention has been made in view of the above problems, and the wheel mounting robot is made to perform the work of removing the temporary tightening nut of the drum brake, and at the same time, the temporary tightening nut is removed. The purpose is to prevent forgetting.

[0008]

SUMMARY OF THE INVENTION The present invention detects the position of a plurality of hub bolts of an axle hub to which a wheel is to be attached by means of a visual sensor, and determines the posture of the wheel gripped by the hand of the wheel mounting robot. The wheel is attached to the axle hub after being corrected based on the position information of the hub bolt so that the position of the bolt hole matches the position of the hub bolt, and the wheel is attached to the hub bolt by a plurality of nut runners attached to the hand. In a method for automatically mounting wheels on a vehicle in which nuts are tightened, prior to detecting the position of the hub bolt, vehicle type information that can be known in advance whether the vehicle body to which the wheels are to be mounted is a drum brake specification or a disc brake specification. If the car body has a drum brake specification, When detecting the position of the bolt, the visual sensor detects the position of the temporary tightening nut that is pre-mounted on any one of the plurality of hub bolts and temporarily tightens the brake drum to the axle hub, and the temporary tightening is performed. It is characterized in that any one of the nut runners on the hand side is fitted into the temporary tightening nut and the temporary tightening nut is removed based on the position information of the nut.

[0009]

1 and 2 are views showing an embodiment of the present invention. FIG. 1 shows a vehicle body of a rear drum brake type, and FIG. 2 shows a vehicle body of a rear disc brake type, which are wheels to be mounted. The vehicle body 1 placed on the carriage 2 is carried into the wheel mounting step 4 by the conveyor 3 and positioned there.

In the wheel mounting step 4, the axle hubs of the front and rear axles (brake discs in the case of disc brakes, brake drums in the case of drum brakes) H
An independent axle lifting device 5 is provided for each of H1 and H2. This axle pushing-up device 5 is provided with a regulation plate 8 that moves up and down while being guided by the guide rod 7 in accordance with the expansion and contraction movement of the air cylinder 6, and as described above, the vehicle body 1 is carried into the wheel mounting step 4 and positioned. Then, the regulation plate 8 of each axle pushing-up device 5 rises and pushes the front and rear axle hubs H1 and H2 by a predetermined amount to absorb the assembly variation of each axle to bring the axle hubs H1 and H2 to a predetermined height position. Serve as a detainee.

Further, in the wheel mounting step 4, independent wheel mounting robots 9 and 10 are provided for the front and rear axle hubs H1 and H2, respectively, and a nut feeding device 11 and a wheel feeding device 12 attached to the wheel mounting robots 9 and 10. Besides, the nut discharging device 1 attached to the wheel mounting robot 10 on the rear wheel side
3 is provided, and the nut supply device 11 and the wheel supply device 12 are controlled by the wheel attachment control device 14 together with the above-mentioned axle lifting device 5. Reference numeral 15 is a robot control panel.

The nut supply device 11 serves to supply a wheel nut to a nut runner 18 of the hand 16 which will be described later, and the wheel supply device 12 determines the rotational position of the wheel W to be mounted on the vehicle body 1. That is, the wheel W is supplied to the hands 16 of the wheel mounting robots 9 and 10 after phase matching is performed.

Hands 1 of the wheel-mounting robots 9 and 10
6 is a hand body 17 and a plurality of nut runners 18
Besides, a CCD camera (hereinafter, simply referred to as a camera) 19 as a visual sensor and a light 26 for illumination are provided. Then, the camera 19 takes an image of the hub bolts B (B1 to B4) of the axle hubs H1 and H2 to which the wheels W should be attached prior to attaching the wheels, and the image is captured by the visual processing device 21 to detect the position of the hub bolt B. Will be done.

More specifically, the wheel mounting step 4 shown in FIGS.
The vehicle bodies of a plurality of vehicle models having different rear brake specifications, that is, the vehicle bodies 1 of a plurality of vehicle models regardless of the rear disc brake specification and the rear drum brake specification are randomly introduced, and prior to the introduction of the vehicle body 1, Vehicle type information (information specific to the vehicle body including the specifications of the rear brake) is transferred from the production instruction device to the wheel attachment control device 14.

Then, in the wheel attachment control device 14, FIG.
Based on the vehicle type information described above, it is determined whether the vehicle body 1 to which the wheels W are attached has the rear disc brake specification or the rear drum brake specification (step S
1, S2), rear disc brake specification is shown in Figure 2
As shown in (3), after waiting for the axle of the vehicle body 1 thrown into the wheel mounting step 4 to be pushed up by the axle pushing-up device 5, the process shifts to the position detection of the hub bolt B (step S3 in FIG. 3).

The position of the hub bolt B is detected by referring to FIGS.
As shown in, front and rear axle hubs (brake discs) H1 captured by the camera 19 of each hand 16
The image of H2 is captured by the visual processing device 21, and the images of a plurality of (4 or 5) target objects of a predetermined size, that is, a plurality of hub bolts B1 to B4 are pattern-matched from the captured image. It is recognized by the method and its position is detected. Then, based on the position data of the plurality of hub bolts B1 to B4 within the field of view of the same camera 19, the center point P1 of the circle Q passing through the centers of the hub bolts B1 to B4.
And the rotation angle θ are calculated.

In this case, the center point P1 of the circle Q is the center position of the axle hubs H1 and H2, and the coordinate center P of the visual field of the camera 19 and the center P2 of the hand 16 coincide with each other. By determining the center point P1 of the axle hubs H1 and H2 as shown in FIG.
Deviations Yo and Zo in the Y and Z directions required to match the center P1 of H2 and the center P2 of the hand 16 are determined.

Further, the rotation angle θ is set such that when the wheel W is gripped by the hand 16, the bolt holes M1 to M of the wheel W are held.
4 and the hub bolts B1 to B4 are in phase with each other, and by obtaining this rotation angle θ, the bolt holes M1 to M4 of the wheel W and the hub bolts B1 to B4.
It is possible to match the phase with 4.

Then, the recognition data of the center point P1 and the rotation angle θ is converted from the camera coordinate system to the robot coordinate system and then transmitted to the robot control panel 15 as position correction data for the wheel mounting robots 9 and 10. It

When the position detection of the hub bolts B1 to B4 is completed in this way, the wheel mounting robots 9 and 10 take the wheel nuts to the nut supply device 11 (step S8 in FIG. 3). That is, the wheel mounting robots 9 and 10 make the tip of the nut runner 18 of the hand 16 face the nut supply device 11, and receive the wheel nut from the nut supply device 11 in the socket portion at the tip of the nut runner 18.

Further, the wheel mounting robots 9 and 10 that have received the wheel nuts go to the wheel supply device 12 for the wheels W (step S9 in FIG. 3) and hold the wheels W by the hand body 17 of the hand 16. At this time, the wheels W are preliminarily adjusted in phase in the wheel supply device 12, and the nut runner 18 is used when gripping the wheels W with the hand 16.
And the phases of the bolt holes M1 to M4 of the wheel W match.

When the wheel W is gripped by the hand 16 in this way, the wheel mounting robots 9 and 10 are moved to the axle hub H.
1, the wheel W is attached to H2 (step S1 of FIG. 3).
0), tighten the wheel nut with the nut runner 18 to fix the wheel W to the axle hubs H1 and H2. At this time, the wheel-mounting robots 9 and 10 receive the wheels W from the wheel supply device 12, and then grip them with the hand 16 based on the correction data of the center point P1 of the axle hubs H1 and H2 and the rotation angle θ detected previously. After correcting the posture of the wheel W, the wheel W is attached to the axle hubs H1 and H2. As a result, the center of the wheel W gripped by the hand 16 and the center of the axle hubs H1 and H2 to which the wheel W is to be attached coincide, and the phases of the bolt holes M1 to M2 on the wheel W side and the axle hubs H1 and H2. The phases of the hub bolts B1 to B4 are the same, and the wheel W can be smoothly mounted on the axle hubs H1 and H2.

On the other hand, as shown in step S2 of FIG. 3, when it is determined that the vehicle body 1 to which the wheel W is to be mounted has the rear drum brake specification in the vehicle type determination, the hub bolt B
When the positions 1 to B4 are detected, the temporary fastening nut N that temporarily fastens the brake drum D1 of the rear axle is detected (steps S4 and S5). That is, FIGS.
In the vehicle body 1 of the rear drum brake specification as shown in FIG. 6, the temporary tightening nut N is temporarily tightened to prevent the brake drum D1 of the rear brake from falling off. Angle θ
The temporary tightening nut N is detected separately from.

This temporary tightening nut N is detected by determining which hub bolt out of the four hub bolts B1 to B4 recognized by image processing the hexagonal temporary tightening nut N is mounted as shown in FIGS. Detected by pattern matching, the hub bolt B (B
2) is specified. And the identified hub bolt B
Based on the position data of No. 2, the phases of the plurality of hub bolts B1 to B4 and the bolt holes M1 to M4 on the wheel W side as described above.
Nut runner 18 corresponding to the hub bolt B2 to which the temporary tightening nut N is attached when the phases are matched.
Specify.

When the position of the temporary tightening nut N is detected in this way, the wheel mounting robot 10 corresponding to the rear axle approaches the brake drum D1 to remove the temporary tightening nut N (step S6 in FIG. 3). ). That is, the wheel mounting robot 10 corresponding to the rear axle is
The posture of the hand 16 is corrected based on the previously detected correction data of the center P1 of the axle hub and the rotation angle θ, and then the nut runner 18 is attached to the corresponding axle hub H2.
That is, it is made to face the brake drum D1 of the rear brake. As a result, the center of the hand 16 and the axle hub H2
The center of the nut runner 18 and 1
8 ... Phase and hub bolts B1 to B4 of axle hub H2
And the phase is matched, and the specific nut runner 18 is fitted to the temporary tightening nut N attached to the hub bolt B2.

The specific nut runner 18 fitted to the temporary tightening nut N is driven in the reverse direction to remove the temporary tightening nut N from the hub bolt B2. The temporary tightening nut N removed from the hub bolt B2 is once housed in the socket portion of the nut runner 18, and is collected by the wheel mounting robot 10 by facing the hand 16 with the nut collecting device 13. That is, the wheel mounting robot 10 causes the tip of the nut runner 18 attached to the hand 16 to face the disc portion 22 of the nut collecting device 13, and temporarily uses an electromagnet or the like (not shown) provided in the disc portion 22. By sucking the tightening nut N, the temporary tightening nut N is extracted from the nut runner 18, and the temporary tightening nut N is dropped and collected in the collecting box 23 below the disc portion 22 (step S7 in FIG. 3). ..

When the temporary tightening nut N is recovered as described above, the wheel mounting robots 9 and 10 receive the wheel nuts from the nut supply device 11 to the respective nut runners 18 (step S8 in FIG. 4) and the hand 16 After gripping the wheel W of the wheel supply device 12 (step S in FIG. 4).
9) and thereafter, the wheel W is mounted in the same procedure as in the case of the rear disc brake specification (step S10 in FIG. 4).

[0028]

As described above, according to the wheel automatic mounting method of the present invention, the temporary tightening nut for temporarily tightening the brake drum of the rear axle is removed by the autonomous operation of the wheel mounting robot for the vehicle body having the rear drum brake. Since the wheels are mounted above, the wheel mounting work can be fully automated by eliminating the work of removing the temporary tightening nuts that used to rely on manual work, and there is no forgetting to remove the temporary tightening nuts. This has the effect of preventing the occurrence of troubles during wheel mounting.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention and is an explanatory diagram showing a state where wheels are mounted on a vehicle body of a rear drum brake type.

FIG. 2 is a view showing an embodiment of the present invention and is an explanatory view showing a wheel mounting state of a vehicle body of a rear disc brake specification.

FIG. 3 is a flowchart showing a procedure for mounting wheels.

FIG. 4 is a flowchart showing a procedure for detecting a hub bolt position.

FIG. 5 is an explanatory view showing the relationship between hub bolts and bolt holes.

FIG. 6 is an explanatory view showing a relationship between a hub bolt to which a temporary tightening nut is attached and a bolt hole.

FIG. 7 is an explanatory view showing a conventional procedure for removing a temporary tightening nut.

[Explanation of symbols]

 1 ... Car body 4 ... Wheel mounting process 9, 10 ... Wheel mounting robot 16 ... Hand 18 ... Nut runner 19 ... CCD camera as a visual sensor B, B1 to B4 ... Hub bolt D1 ... Brake drum D2 ... Brake disc H1, H2 ... Axle hub M (M1 to M4) ... Bolt hole N ... Temporary tightening nut W ... Wheel

Claims (1)

[Claims] 1. A position of a plurality of hub bolts of an axle hub to which a wheel is to be attached is detected by a visual sensor, and a posture of a wheel gripped by a hand of a wheel mounting robot is determined so that a position of a bolt hole of the wheel corresponds to a position of the hub bolt. Automobile wheel wheels that are corrected based on the position information of the hub bolt so that the wheels are attached to an axle hub, and the wheel nuts are tightened to the hub bolts by a plurality of nut runners attached to the hand. In the mounting method, prior to detecting the position of the hub bolt, it is determined based on the vehicle type information that the vehicle body to which the wheels are to be mounted has the drum brake specification or the disc brake specification based on the vehicle type information that is known in advance. In the case of brake specifications, when detecting the position of the hub bolt, Of the hub bolts, which are previously attached to one of the hub bolts to temporarily tighten the brake drum to the axle hub, are detected by the visual sensor, and the hand side is detected based on the position information of the temporary tightening nut. One of the nut runners is fitted to the temporary tightening nut, and the temporary tightening nut is removed.