JP3006276B2 - Work assembly accuracy measurement method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work supporting device,
In particular, the present invention relates to a work supporting device for measuring assembly accuracy.

[0002]

2. Description of the Related Art It is important to control product quality in order to stabilize product quality or improve production efficiency. For this reason, at present, not only quality control of individual products but also improvement of the quality of products to be produced in the future based on measured quality information of current products is performed. Thus, quality control has become increasingly important in recent years. This is no exception in the manufacture of automobiles. Assembling accuracy is an important management item related to the performance and durability of a product in the quality of an automobile body. In a product composed of a large number of workpieces, such as an automobile, even if the mounting error between adjacent workpieces is very small, it may cause a failure in other mounting parts due to the error. For this reason, high accuracy is required for quality control of work assembly accuracy. FIG. 10 is a perspective view showing a conventional assembling accuracy measuring device and a work W, that is, a floor body, which is an object to be measured. As illustrated, in the following description, the width direction of the work is defined as the X direction, the work transfer direction is defined as the Y direction, and the vertical direction is defined as the Z direction. As shown in FIG.
A first locating pin 13 for positioning the front part of the floor body 11 and a second locating pin 15 for positioning the rear part thereof are attached to the accuracy measuring stage 10, and the floor body 11 placed on the measuring stage 10 is positioned. It has become. The measurement stage 10 is provided with six reference posts 18 to 23 for positioning and supporting the floor body 11 in the vertical direction, that is, the Z direction, so as to support the floor body 11 placed on the measurement stage 10. It has become. The position supported by the reference posts 18 to 23 is preferably a controlled position such as a clamp position or a positioning position of a work held by a clamp member that holds the work. Support by post. Further, the measuring stage 10 is provided with a three-dimensional measuring device 29 to which an upward measuring element 25 extending upward and a downward measuring element 27 extending downward are attached as shown in the figure, and both measuring elements are movable. It has become.
Of these tracing styluses 25 and 27, the upward tracing stylus 25 measures the measurement position on the lower surface of the floor body 11, and the downward tracing stylus 27 measures the measurement position on the upper surface of the floor body 11. It has become. Therefore, for example, when measuring the position of the locate hole on the lower surface of the floor body 11, the measurement is performed by moving the upward tracing stylus 25 directly below the locate hole to be measured. In this way, the assembly accuracy of the skeleton is measured by measuring each point of the floor body 11. Although not shown, three-dimensional measuring machines 29 are installed one by one on the left and right sides of the measuring stage 10 so that measurement can be performed from both sides.

A procedure for measuring the position of a measurement point on the lower surface of a vehicle body using such a measuring device will be described below. First, when the floor body 11 as a work is placed on the assembly accuracy measurement stage 10, the floor body 11
Is positioned on the stage 10 by the first locate pin 13 and the second locate pin 15. At the same time, the clamp position of the floor body 11 is supported by each reference post. Subsequently, the upward tracing stylus 25 attached to the three-dimensional measuring machine 29 is moved to a position immediately below the position of the locate hole to be measured, and the position of the locate hole is sequentially measured.

[0004]

However, in the above-described measuring apparatus, both the first locate pin 13 and the second locate pin 15 are fixed to the stage 10.
For this reason, if there is a dimensional error in the positional relationship between the first locate hole and the second locate hole of the floor body 11, that is, in the pitch, when the locate holes are positioned by the locate pins 13, 15, the locate pins 13, 15 are positioned. The supporting member or the floor body 11 itself is bent. As described above, if the reference pitch between the two locate holes is deviated, the pitch between the two reference locate holes as well as the pitch between the other locate holes cannot be accurately measured. If the locate hole at the bottom of the vehicle body is present adjacent to the reference posts 18 to 23 supporting the floor body 11, the coordinate measuring machine 29 may interfere with the reference post during position measurement. In such a case, the position of the locate hole cannot be measured. In particular, in the case of IBS, positioning and clamping are performed by the same jig, and the clamping position and the locating position are the same. For this reason, since the locate hole is located in contact with the reference post, the upward tracing stylus 25 cannot be located immediately below the locate hole. In general, the floor body 11 supported at the locate position is
In this case, since the supporting member is supported at the clamp position as described above, there is a problem that the measurement result on the measuring stage does not always match the actual assembling accuracy on the assembling stage.

[0005] In addition, as shown in FIG. 11, there is a case where the location of the locate hole 33 is calculated by photographing the vicinity of the locate hole 33 by the two-dimensional camera 31 and processing the photographed image data. However, also in this case, the work is supported and supported via the clamp position and the non-management position, and the measurement result does not always match the actual assembly accuracy at the assembly stage. The present invention has been made in view of the above problems, and has as its object to accurately measure an assembly error occurring in a work placed on an assembly stage.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a work before assembly comprising a plurality of members.
To the assembly stage with multiple locators
And the workpiece is held at the correct position of the plurality of locators.
With the positioning by the located locate member,
After assembling the work, the work
With the rock supported by the locate member, the location
Releases the holding force to position the port member to the correct position
By doing so, the locate member is moved from the workpiece.
Moved under force, and the location
The feature is to measure the amount of deviation of the sheet member from the normal position
This is a method of measuring work assembly accuracy .

[0007]

According to the present invention, the locating member held at the regular position supports or holds the loose workpiece carried into the assembling stage before assembly, and positions the work. After the loaded work is assembled by welding and the positioning and holding of the locate member is released , the locate
It moves with the force from the work. At this time, the movement amount of the locate member from the initial regular position is measured.

[0008]

[0009]

Embodiments of the present invention will be described below with reference to the drawings. The members already described are given the same numbers. In the following description, the direction of the work is defined as the X direction, the direction of transporting the work is defined as the Y direction, and the vertical direction is defined as the Z direction. FIG. 1 is a perspective view showing a floor body 11 constituting a part of a vehicle body. The floor body 11 is roughly composed of four members, an engine compartment 11a, a front floor portion 11b, a rear floor portion 11c, and a sill inner portion 11d, and measures a relative position of a locate hole in each member. By doing so, the assembly accuracy is managed. The position indicated by the arrow in FIG. 1 is a main management position of each member. FIG. 2 is a perspective view showing a device for measuring the assembly accuracy of a work according to the present embodiment. As shown in FIG. 2, a first positioning member 35 for positioning a front portion of the floor body 11 as a work is fixed to the measurement stage 10.
The first positioning member 35 has a first reference receiving member 36 for positioning a work such as the floor body 11 in the Z direction.
Are protruding. For this reason, the first locate hole 37 in the front part of the floor body 11 that fits into the first locate pin 13
Is always fixed at a fixed position. Measurement stage 10
Is provided with a second positioning member 42 for positioning the rear portion of the floor body 11, and is configured to position and measure the position of the second locate hole 38 at the rear portion of the floor body 11. As shown in FIG. 3, a guide rail 44 extending in the Y direction is attached to the support member 43 of the second positioning member 42, and the second reference receiving member is movable along the guide rail 44 in the Y direction. 45 are attached. Second reference receiving member 4
5 is provided with a second locate pin 15 protruding therefrom. Since the second locate pin is movable in the Y direction within a range including the regular gauge positioning position, which is a standard assembly position, moving the second locate pin 15 causes the first locate pin 15 to move.
The pitch between the locate hole 37 and the second locate hole 38 can be adjusted for each individual, and the floor body 11 can be positioned on the stage 10. Also, the second support member 4
A displacement gauge 46 is attached to 2 to measure the amount of movement of the reference receiving member 45 in the Y direction.

[0010] Then, as shown in FIG.
At 0, six measurement positioning members for measuring the assembly accuracy of the positioning position of the floor body 11 are installed.
As shown in FIG. 4, a support plate 51 which is movable along a guide rail 49 extending in the X direction is attached to a support member 48 of the third measurement positioning member 47 which is one of them. The support plate 51 is provided with a third reference receiving member 57 which is movable in the Y direction via a guide rail 53 extending in the Y direction and has a third locate pin 55 projecting therefrom. Thus the third
Since the reference receiving member 57 is movable in both the X and Y directions, if the position of the third locate hole 59 to be fitted is shifted from the standard position, the third reference receiving member 47 is moved to Third locate pin 55 and third locate hole 59
Can be fitted. The third positioning member 47 has a third
A displacement gauge 46 for detecting the amount of movement of the locate pin 55 in the X and Y directions is attached, and a third locate hole 59 is provided.
The deviation amount from the standard position can be measured. The other measuring positioning members 63 to 67 installed on the measuring stage 10 have the same configuration, and all have locating pins 68 to 72 protruding and movable reference receiving members 73 to 77. In addition, a displacement meter 46 for measuring the amount of movement of the reference receiving member having the locate pin in the X and Y directions is attached. Thus, each positioning member 35, 42, 47, 63-67
Is movable in the X and Y directions, so the floor body 1
When positioning the stage 1 on the stage 10, the positioning member 3
5, 42, 47, 63 to 67 and the floor body 11 do not bend.

Further, the measuring stage 10 is provided with a three-dimensional measuring machine 29 having a movable downward measuring element 27, and the position of a measuring point on the upper surface of the floor body 11 is measured by the downward measuring element 27. It has become.

A procedure for measuring the assembling accuracy of the vehicle body by the accuracy measuring device having the work supporting device according to the present invention will be described. First, when the floor body 11, which is a work, is carried into the measurement stage 10, the first locate pin 13 is fitted into the first locate hole 37 provided in the front part of the floor body 11, and the second locate hole 38 provided in the rear part. Then, the second locate pin 15 is fitted to the second position pin, and the floor body 11 is positioned. In addition, both locate holes 3
If the pitches of the holes 7 and 38 are deviated from the regular pitches, the second locate pin 15 is moved in the Y direction so that both the locate holes 37 and 38 are located in the locate pins 13 and 1.
5 is fitted. At the same time, the positioning holes corresponding to the measurement positioning members are fitted into the measurement positioning members 47, 63 to 67 installed on the stage 10. If the pitch between these locate holes and the first locate hole 37 is shifted from the regular pitch, the positioning members 47 for measurement are used.
By moving 63 to 67 in the X or Y direction according to the amount of displacement, the locate pins 55 and 68 to 72 are fitted into the locate holes. Thus, each locate pin 55,
When the positioning is completed by fitting 68 to 72 into the locate holes, the second positioning member 42 and the measuring positioning members 47 and 63 are attached by the displacement meter 46 attached to each member.
The movement amount from the standard position of ~ 67 is measured, and the assembly accuracy of the floor body 11 is measured.

As described above, by using the work supporting apparatus of the present embodiment, the work can be supported at the same supporting position as the supporting position on the assembly stage 10, and the assembly accuracy of the work can be measured. For this reason, the assembling accuracy of the floor body 11 mounted on the assembling stage can be extremely accurately measured, and information useful for improving the assembling accuracy can be fed back to the production of the next vehicle.

Another embodiment will be described below. FIG.
1 is a sectional front view of a work assembling stage having a work supporting device according to the present invention. As shown in FIG. 5, a frame 101 is installed on the stage, and the NC locator 10 holding the roof is mounted on the frame 101.
3. A plurality of side NC locators 105 for positioning a body side such as a front pillar and a plurality of floor NC locators 107 for positioning a floor body are attached. FIG. 6 is a side view showing the side NC locator 105. As shown in FIG. 6, a plate member 111 that is movable in the Y direction via a guide rail 109 is attached to the frame 101 and can be positioned by a Y-axis motor 113. A sliding member 115 slidable in the X direction is attached to the plate member 111, and can be positioned by an X-axis motor 117. Also, the sliding member 115
A locator supporting member 123 having an NC locating member 119 and being movable along a guide rail 121 extending in the Z direction is attached to the Z-axis motor 125.
The position is determined by Thus, N
The C locating member 119 is movable and is positioned at an arbitrary position. Also, as shown in FIG. 6, the NC locating member clamps and positions the work W, and is movable and positioned while clamping the work W. As shown in FIG. 7, the motors 113, 117, and 125 are connected to a controller 133 via amplifiers 127, 129, and 131, respectively, and are controlled by the controller 133 to perform positioning control and positioning release control. ing. In the state where the positioning is released, the NC locate member 119 moves when it receives an external force. In addition, each motor 1
Since encoders (not shown) are connected to 13, 117, and 125, the displacement of the motor can be measured. In addition,
The above description is about the NC locator for positioning the body side. However, other NC locators are also movable similarly, and the amount of movement can be measured by the encoder, and the positioning control and positioning are performed by the connected controller. Release control can be performed.

The operation of such an NC locator, that is, an assembling stage on which a work supporting member is installed, is described on the floor N
The C locator will be described as an example based on the flowchart of FIG.
FIG. 9 is a perspective view showing an assembly stage on which floor NC locators 141 to 148 are installed. First, the loose parts carried into the assembly stage, that is, the work W before assembly, are clamped and positioned by the NC locators 141 to 148 and other NC locators (not shown), and assembled by welding (S
1). At this time, each work W is positioned at the regular gauge positioning position by the NC locator. When the welding is completed, the NC locators 141 to 148 to be positioned are
The controller 133 sets the positioning release state (S
2). At this time, if the assembly position of each part is a regular position, each of the NC locators 141 to 148 does not move even if the positioning is released. However, if the assembling position is deviated from the normal position, the stress caused by the distortion remains in the vehicle body positioned at the locator which is the normal gauge position. Therefore, when the positioning of the NC locators 141 to 148 is released, the vehicle body is simultaneously released. Are released, and the NC locators 141 to 148 move (S3). The movement amount of each of the NC locators 141 to 148 is detected as a pulse signal by an encoder (not shown) connected to each motor (S
4) The deviation from the normal position is calculated by multiplying the resolution (S5). The displacement in each axis direction thus obtained, that is, the displacement is synthesized to determine the displacement of the work (S6). The obtained result is fed back to the production of the next vehicle by, for example, adjusting the regular gauge position (S7).

As described above, the assembling accuracy can be measured at the stage of assembling, so that a separate measuring device is not required. The measurement can be performed in a very short time. further,
Since the clamp and the support position are the same at the time of assembling and at the time of measurement, it is possible to measure the assembling accuracy that occurs when the assembling stage is placed on the assembling stage, and more accurate feedback is possible.

[0017]

As described above, according to the present invention ,
Assembling at the assembly stage to assemble the work
Accuracy can be measured. Therefore, separately measured
Install equipment and secure space for it
No need. Measure assembly accuracy in a very short time
can do. In addition, during assembly and measurement
Since the support or holding position for the workpiece is the same,
Assembly precision generated when placed on the assembly stage
Degree can be measured, helping to improve assembly accuracy
Provide very accurate feedback to the next car production
It is possible that.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a floor body constituting a part of a vehicle body,

FIG. 2 is a perspective view showing a work assembly accuracy measuring apparatus according to the embodiment;

FIG. 3 is a perspective view of a main part of a second positioning member,

FIG. 4 is a perspective view of a main part of a positioning member for measurement,

FIG. 5 is a cross-sectional front view of a stage for positioning and temporarily fixing each work constituting the vehicle body,

FIG. 6 is a side view of a side NC locator;

FIG. 7 is a block diagram related to motor control;

FIG. 8 is a flowchart showing an operation order;

FIG. 9 is a perspective view showing an assembly stage on which a floor NC locator is installed;

FIG. 10 is a perspective view showing a conventional assembly accuracy measuring device and a floor body as an object to be measured.

FIG. 11 is a perspective view showing a state in which the position accuracy of a locate hole is measured by a two-dimensional camera.

[Explanation of symbols]

11: floor body 13: first locate pin 15
... Second locate pin 29... Three-dimensional measuring machine 35.
... 1st locate hole 38 ... 2nd locate hole 42 ... 2nd positioning member 4
6 Displacement meter 47 Third positioning member 63 to 67 Measurement positioning member 105 Side NC locator 107 Floor NC locator 133 Controller

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B23P 19/00

Claims (1)

(57) [Claims] An unassembled work comprising a plurality of members is carried into an assembling stage provided with a plurality of locators, and the work is positioned by a locating member held at a proper position of the plurality of locators. By assembling the work, and after assembling the work, in a state where the work is supported by the locating member, by releasing the holding force for positioning the locating member to a normal position, the locating member is A work assembling accuracy measuring method, wherein the work is moved by receiving a force from a work, and a displacement amount of the locating member from a normal position due to the movement is measured.