JPS60207756A - Grinding work - Google Patents

Abstract

PURPOSE:To correctly grind the corner part having positioning error and dimension error by detecting the position information of each plane and grinding the vicinity of the crossing part according to the position information for the both surfaces, when the welded corner part of a sheet-metal box body is ground for each one-side surface. CONSTITUTION:Grinding is performed by operating a grinder 34 and driving a transfer frame 8 forward in H direction. Since the position in the direction of the height of the upper surface of a workpiece A varies during grinding, said variation is detected by a profiling stylus 38, and a servomotor 38 is driven according to the detection amount, and grinding is performed along the upper surface of the work A, adjusting the position in the vertical direction. The detected amount of variation of the work A is memorized into a memory apparatus. After the upper-surface grinding is completed, the side surface in the vicinity of a corner part is ground by the similar procedure after the frame 8 is advanced a little. After the side-surface grinding is completed, the grinder 34 is lowered by the amount added with the correction amount (alpha), and the grinder 34 is operated according to the detected values during the upper-surface grinding and side- surface grinding, and the corner part is aslantly ground by driving the frame 8.

Description

Detailed Description of the Invention (Technical Field) The present invention relates to a grinding method, and particularly to a grinding method suitable for automatically grinding or polishing corner parts such as the corners of a sheet metal box. Related.

(Prior Art) Conventionally, a box made of sheet metal has been manufactured by arranging four side plates orthogonal to each other and welding adjacent side edges from the outside. In this case, since the weld bead is formed in a raised convex shape, the weld bead portion is removed in order to improve its appearance. This work is usually done manually using a hand grinder, which poses problems in that the finished quality is not constant and the work efficiency is reduced due to worker fatigue.

Therefore, various attempts have been made to automate the above-mentioned work, and at present, a device that uses a carbide cutter or a grinding wheel to chamfer a corner with an inclined planar shape as described above has been put into practical use. . However, in the above-mentioned apparatus, the cutter and grindstone only perform grinding while linearly moving along a predetermined trajectory, and therefore, when processing a relatively thin box, there is a positioning error of the box. If there is a dimensional error in the box due to welding, there may be parts that are not ground at all, or there may be parts that are ground all the way to the inside.

(Object of the Invention) The present invention has been made in view of the above, and its purpose is to prevent positioning errors and eliminate positioning errors at intersections to be ground, such as corners of a box.
It is an object of the present invention to provide a grinding method that can perform accurate and good grinding along a corner even when there is a dimensional error.

(Structure and operation of the invention) The grinding method of the present invention, which meets the above object, is a grinding method for grinding near the intersection of mutually intersecting planes, in which one plane is first ground along the longitudinal direction, and , detect the positional information of this plane during this grinding, then grind the other plane along the longitudinal direction, detect the positional information of this plane during grinding, and calculate the position of both sides detected above. Find the location information near the intersection from the information,
The feature is that the vicinity of the intersection is ground according to this positional information.

As mentioned above, the positional information of each plane is stored in advance, and the intersection is ground based on the positional information near the intersection obtained from this information, so there is no positioning error or dimensional error at the intersection. Even if there is a gap, the grinding process can be performed accurately along the intersection, and it is possible to perform a good grinding process. Moreover, since the position of each plane is detected at the same time as the grinding of each plane, machining and detection can be performed at the same time, which is extremely efficient.

(Example) Next, an example of the grinding method of the present invention will be described, but first, an example of a processing apparatus used therein will be described in detail with reference to the drawings.

In the figure, reference numeral 1 denotes a base, and a main body frame 2 is attached to the base 1. This main body frame 2 is
It is arranged so that its position in the vertical direction can be adjusted with respect to the above-mentioned base structure, and a pair of parallel rails 3.3 extending in the longitudinal direction are arranged on the upper surface thereof. Further, a ball screw 4 serving as a horizontal drive shaft is rotatably supported between the rails 3 and 3 on the main body frame 2.
A gear reduction mechanism 7 is operated by an electric motor 6 fixed to one end.
It is designed so that it can be rotated through. Note that a magnet 5 for fixing the workpiece is attached to the side of the main body frame 2.

A conveyance frame 8 is placed on the main body frame 2, and this conveyance frame 8 is fitted with the rail 3.3 on the back side thereof and slides on the rail 3.3. A sliding member 9.9 is attached. Furthermore, a ball nut 11 is provided on the back side of the conveyance frame 8.
is fixed, and this ball nut 11 is connected to the ball screw 4.
is screwed into the transport frame 8 by rotation of the ball screw 4.
can be driven in the horizontal direction (hereinafter referred to as the H direction).

A pair of guide rails 12 and 12 are installed on the conveyance frame 8 and are arranged parallel to each other. The base end thereof is fixed to the transport frame 8, and the free end thereof extends in a direction perpendicular to the transport direction (H direction) of the transport frame 8.

Further, a rack 13 formed in an arc shape similar to that described above is attached to the outer surface of one of the guide rails 12.12. Note that the transport frame 8
An auxiliary rail 14.14 having a shape substantially similar to that described above is arranged inside each of the guide rails 12.12.

Reference numeral 16 denotes a rotating frame, and on both sides of the rotating frame 16, a first guide roller 17 that rolls on the upper surface of the guide rail 12 and a second guide roller 17 that rolls on the back surface of the guide rail 12 are provided. The guide roller 18 and the auxiliary rail 14
A third guide roller 19 that rolls on the upper surface of the roller is pivotally supported. That is, by sandwiching the guide rail 12 from both sides between the first guide roller 17 and the second guide roller 18, the rotating frame 16 is moved around the guide rail 1.
2.12 in the circumferential direction (hereinafter referred to as the R direction), and by providing the auxiliary rail 14 and the third guide roller 19, the above supported state is ensured. be. As shown in FIG. 5, the first guide roller 17 and the second guide roller 18 are in a positional relationship such that an extension line connecting both axes thereof passes through the center of the circular arc portion of the guide rail 12. It is located in
As a result, the first guide roller 17 and the second guide roller 1
8 means that it moves along the guide rail 12 with the center of curvature of the arcuate portion as its center of rotation. On the other hand, the third guide roller 19 is disposed at a position that is a predetermined angle θ away from the rotation center of the line connecting the axes of the first guide roller 17 and the second guide roller 18. As a result, the arcuate portion of the auxiliary rail 14 for the third guide roller 19 is located at a position where its starting point B and end point C are phased by the angle θ with respect to the arcuate portion of the guide rail 12. It is formed. Note that the surface of the straight portion of the auxiliary rail 14 is located at a lower position than the surface of the straight portion of the guide rail 12 due to the third guide roller 1.
9 is located at a lower position than the first guide roller 17 with respect to the direction connecting the axes of the first guide roller 17 and the second guide roller 18.

and three guide rollers 17.18.19 as above
An electric motor 21 for driving the rotating frame 16 is further attached to the rotating frame 16.

This electric motor 21 is attached downward to the rotating frame 16 as shown in the figure, and a bevel gear 22 is attached to its output shaft. On the other hand, a drive shaft 23 is supported on the frame 16 at a position coaxial with the first guide roller 17.
The bevel gear 24 and pinion 26 are fixed. The bevel gear 24 is meshed with the bevel gear 22 on the motor 21 side, and the pinion 26 is meshed with the rack 13 described above, so that when the output shaft of the motor 21 rotates, the pair of bevel gears 22 and 24 are engaged with each other. The pinion 26 is driven through the guide rail 12, and the entire rotating frame 16 can be rotated in the R direction along the guide rail 12. Note that 25 is an electromagnetic brake, which is used to prevent the output shaft of the electric motor 21 from rotating and to hold the rotating frame 16 at a desired rotational position.

The rotation frame 16 further includes a tool support frame 2.
7 is supported, and this tool support frame 27 is driven by the tool driving means 20 in the direction toward and away from the workpiece surface (hereinafter referred to as the Z direction). The tool driving means 20 will be explained. First, a DC servo motor 28 for driving a tool support frame 27 is mounted upward on the rotating frame 16, and its output shaft is connected to a ball screw 31 via a gear reduction mechanism 29. This ball screw can be driven to rotate. On the other hand, 32 is a cylinder driven by fluid, such as an air cylinder, and a ball nut 33 is fixed to the side of the air cylinder 32, and this ball nut 33 is engaged with the ball screw 31.

That is, the air cylinder 32 can be driven in the vertical direction by the servo motor 28 via the ball screw 31 and the ball nut 33. The tool support frame 27 is attached to the tip of the air cylinder 32, and a rotary tool such as an air grinder 34 is attached to the tool support frame 27. Further, as shown in FIG. 4, the air cylinder 32
A recess 39.40 is formed in each of the 0 side and the free end of the tool support frame 27, and this recess 39.40
Rails 41 and 42 provided on the rotating frame 16 side inside
The air cylinder 32 and the tool support frame 27, which are driven in the vertical direction, can be guided therein.

In addition, 36 is an electromagnetic brake for the servo motor 28, and 37 is an electromagnetic brake for the servo motor 28.
is a brake for the air cylinder 32. The reason why brakes 36 and 37 are added to each of the servo motor 28 and the air cylinder 32 in this way is to enable the air grinder 34 to perform both constant pressure grinding and constant depth of cut grinding. That is, the brake 37 for the air cylinder 32 is operated to fix the iron, and the servo motor 28 is driven to lower the air grinder 34 to perform fixed depth of cut grinding, while the electromagnetic brake 36 for the servo motor operate and fix its output shaft,
Air grinder 3 by driving the iron of air cylinder 32
4 is lowered to perform constant pressure grinding.

In addition, a copying stylus 38 is arranged at a position in front of the air grinder 34 in the rotating frame 16 in the direction of conveyance by the conveyance frame 8, and the copying stylus 38 is used to generate a plane pattern after copying grinding of two orthogonal planes is completed. The arcuate locus of the corner portion of the workpiece is calculated based on this memory, and the DC
It is possible to control the operation of the servo motor 28 in two directions.

Next, a specific example of the method of the present invention will be described, taking as an example a case where a corner portion of a workpiece A, such as a sheet metal box, is ground using the above-mentioned apparatus.

(1) First, the side plate of the workpiece A is attracted to the magnet 5 of the main body frame 2.

(2) Lower the main body frame 2 and use the copying stylus 38.
is brought into contact with the top surface of the workpiece A, and the corner part of the workpiece A (more precisely, the center position of the R part to be machined)
is located at approximately the same position as the center of curvature of the guide rail 120.

In this case, it is assumed that the grinder 34 is disposed downward so as to be able to grind the upper surface of the workpiece A near the corner.

(3) Operate the air cylinder 32 and grinder 34
is lowered to bring the grindstone into contact with the upper surface of the workpiece A. In this state, the brake 37 is operated to lock the output shaft of the air cylinder 32.

(4) By operating the servo motor 28, the grinder 34 is pulled up by a predetermined distance.

(5) By retracting the transport frame 8, the grinder 34 is positioned further back than the rear end of the workpiece A (hereinafter referred to as the original position).

(6) The grinder 34 is lowered by the servo motor 28. The descending distance is the distance obtained by adding the depth of cut to the above-mentioned raised distance.

(7) Grinding is performed by operating the grinder 34 and driving the transport frame 8 forward (in the H direction). In this case, during grinding, the position of the top surface of the workpiece A in the height direction varies, and this variation is detected by the copying stylus 3B. Then, the servo motor 28 is driven according to this detected amount, and the grinder 34 grinds along the upper surface of the workpiece A while adjusting the vertical position of the grinder 34. Further, at this time, the detected amount of variation along the longitudinal direction of the workpiece is stored in the storage device.

(8) When the grinding of the upper surface is completed, the grinder 34 is stopped, and the air cylinder 32 and the servo motor 28 are respectively activated to pull up the grinder 34 and return the transport frame 8 to its original position.

(9) Rotate the rotating frame 16 in the R direction along the guide rail 12 by driving the electric TA21,
The grinder 34 and the copying stylus 38 are each arranged horizontally.

(10) Next, after slightly advancing the transport frame 8 on the side surface near the corner of the workpiece A, proceed as described in (3) above.
Grinding is carried out in the same manner as in (7).

(11) When the grinding of this part is completed, the grinder 34
At the same time, the servo motor 28 raises the grinder 34 by a predetermined amount.

(12) Return the transport frame 8 to its original position.

(13) The rotating frame 16 is rotated by a predetermined angle by the electric motor 21, and in this state, the brake 25 is activated to lock the R axis.

(14) The grinder 34 is operated by the servo motor 28,
The scale is lowered by an amount equal to the correction amount α added to the above-mentioned raised scale. This correction amount α is for correcting the error that occurs between the center position of the guide rail 12 and the position of the corner part of the set workpiece (more precisely, the center position of the R part at the corner part). This is to perform grinding while making various changes depending on the position of the corner portion detected during each grinding of the above-mentioned top and side surfaces. Note that this correction amount α will be described later.

(15) The corner portion is ground obliquely by operating the grinder 34 and driving the conveyance frame 8.

(16) When the above grinding is completed, the above (11) to (1)
The corner portion is completed by repeating the procedure 5) a required number of times until the grinder 34 is in the downward position.

Next, a procedure for calculating the above-mentioned correction amount α will be explained. Now, considering the case where the center position of the curvature of the guide rail 120 and the center position of the R section to be machined match, in this case there is no need to vary the position of the grinder 34 in the Z direction, The rotating frame 16 may be rotated while being held in position. However, as shown in FIG. 6, a positioning error occurs when centering the workpiece A, or the workpiece A itself is deformed along the longitudinal direction, so that the center of curvature position O of the guide rail 12 and the center position P of the R section to be machined.
If they do not match, the R portion cannot be machined while the position of the grinder 34 in the Z direction is maintained as described above.

Therefore, in this case, the positions in the two directions are varied depending on the position of the grinder 34 in the R direction.

First, assuming that the amount of change in the squareness of the corner part is extremely small, the positions of the top and side surfaces near the R part of the workpiece A0) have already been detected, so from this detected amount, the R part to be machined is The deviation between the center position P of the guide rail 120 and the curvature center position 0 of the guide rail 120 can be adjusted. Now, if a circle with the same radius as the guide rail 12 is drawn from the actual center position P of the R section, there will be a distance α in the radial direction between this virtual circle and the guide rail 12, as shown in FIG. Only the gap lives. Therefore, by correcting the Z-direction position of the grinder 34 by the deviation amount α according to the R-direction position, the grinder 34 moves on the virtual circle;
Substantially the same results can be obtained. As a result, even if the center position of the R section to be machined deviates from the center position of the curvature of the guide rail 120, it is possible to grind the R section into a predetermined shape. Note that it is preferable that the width of the grindstone used in this case is sufficiently larger than the radius of the R portion to be processed.

The above embodiment is a method suitable for processing workpieces where the amount of change (error) in the squareness of the corner portion is small, such as a relatively large sheet metal box, but the angular error at the corner portion is In the case of a relatively large workpiece A, or when the angle of the corner part is not originally a right angle, the inclination of the surface can be adjusted by grinding and detecting each plane two or more times as shown in Fig. 7. What is necessary is to determine the angle, determine the position of the intersection based on the inclination angle of both sides, and grind the intersection based on this position information.

In addition, in any of the above embodiments, the intersection portion is shaped like an R (
Although an example of grinding is shown in which the cross-sectional shape is arcuate, the cross-sectional shape of the intersection is not limited to this.

According to the above grinding method, the position of the corner portion is
Even if there is a deviation due to a deformation error or a positioning error, the grinding process can always be performed correctly along the corner portion, so that good machining can be performed. Moreover, since the position information of the cough surface is detected at the same time as the flat surface is ground, it is possible to perform the grinding process with extremely high efficiency. Furthermore, if a guide rail curved in an arc shape is used as described above, and the rotary tool is moved along this guide rail to grind the corner part, the rotary tool will move to the detected position of the two planes. The R portion can be processed by simply controlling the position in one of the two directions according to the calculated correction amount based on the information, and the control is simple and convenient.

Although one embodiment of the grinding method of the present invention has been described above, the method of the present invention is not limited to the above embodiment, and can be implemented with various modifications. For example, the above shows a processing procedure in which the grinder is moved by a predetermined angle in the R direction, fixed at this angle, grinding is performed along the elongated direction, and then further moved by a predetermined angle in the R direction. However, as shown in FIG. 8, for example, it is also possible to grind in the longitudinal direction while reciprocating the grinder in the R direction. Further, in the above description, an example is shown in which both an air cylinder and a servo motor are used together as the two-direction drive source, but it may also be implemented using only the servo motor. Note that it is clear that the term "grinding" as used in the present invention includes all processing methods in which the surface of a workpiece is scraped off with a grindstone.

(Effects of the Invention) The grinding method of the present invention is configured as described above, and therefore, according to the grinding method of the present invention,
Even if there is a positioning error or dimensional error at the intersection of the workpiece, there will be no parts that cannot be ground or parts that will be ground to the inside like in conventional methods, and the process will be performed correctly along the intersection. It becomes possible to perform good grinding.

[Brief explanation of drawings]

FIG. 1 is a front view of the entire processing apparatus used for carrying out an example of the method of the present invention, FIG. 2 is a front view of the main parts thereof, and FIG.
The figure is a side view thereof, FIG. 4 is a plan view thereof, FIG. 5 is a side view showing an example of the guide rail and auxiliary rail used in the above device, and FIG. 6 is an explanation of a correction method in the Z-axis direction in the above device. FIG. 7(b) is an explanatory diagram of another embodiment of the method of the present invention, and FIG. 8 is an explanatory diagram showing an example of a modification of the grinding procedure. A... Workpiece Patent applicant: Daikin Industries, Ltd. Figure 7 Figure 8

Claims (1)

[Claims] 1. In a grinding method for grinding near the intersection of mutually intersecting planes, one plane is first ground along the longitudinal direction, and the position of this plane is adjusted during this grinding DI. Detect the information, and then grind one plane along the longitudinal direction, detect the position information of this plane during grinding, and calculate the intersection from the position information of both sides detected in step 1 above. Grinding 1!i11 processing method characterized by obtaining positional information near the part and grinding the vicinity of the intersection according to this positional information.The processing apparatus used.