KR100925647B1 - Sensing device and its method for compensating tool position processing oil-groove inside of engine cylinder - Google Patents

Abstract

The present invention relates to a sensing device for position correction of a machining tool for processing oil grooves on a cylindrical inner surface, and a position correction method for a machining tool using the same, and an object thereof is to mount a machining tool head including a machining tool on a robot arm to install an engine cylinder. For machining oil grooves on the inner surface of cylindrical materials, such as to improve the degree of processing and to position the machining tool for machining oil grooves on the inner surface of the cylinder to provide more accurate information for creating the cutting path of the processing tool head. The present invention provides a sensing device and a position correction method for a machining tool using the same. To this end, the present invention is equipped with a machining tool for machining oil grooves and a spindle motor for rotating the machining tool, mounted on a robot arm, moved by a robot arm, and installed on a machining tool head for machining oil grooves on an inner surface of a cylinder. A displacement sensor for measuring the height of the machining tool from the inner surface of the cylinder and providing information for height correction of the machining tool; And when the machining tool head is moved along the machining path by the robot arm so that the machining tool is positioned at the vertical upper portion of the oil hole formed in the cylinder, the image including the oil hole is photographed, but the design criteria is centered in the center of the photographed image. And a visual sensor installed at the processing tool head so that the center of the oil hole is located and measuring the distance from the center of the image of the oil hole to be actually taken to provide information for correcting the position of the processing tool. It provides a sensing device for position correction of the processing tool for processing the oil groove on the inner surface and a position correction method using the same.

Displacement sensor, visual sensor, machining tool head, inner cylinder, oil groove

Description

Sensing device and its method for compensating tool position processing oil-groove inside of engine cylinder

The present invention relates to a sensing device for position correction of a machining tool head when machining oil grooves on an inner surface of a cylindrical material such as an engine cylinder, and a position correction method using the same. The present invention relates to a sensing device for position correction of a machining tool for machining an oil groove on an inner surface of a cylinder that can increase precision by moving along an orbit, and a position correction method for a machining tool using the same.

1 shows an exemplary view showing an example of an oil groove formed on an inner surface of an engine cylinder. The engine cylinder 10 is provided with a plurality of oil holes 11 for injecting oil into the cylinder and oil grooves 12 for evenly injecting the oil introduced through the oil holes into the cylinder inner surface. have.

On the other hand, most of the oil grooves formed on the inner surface of the engine cylinder are processed by a manual work by the operator to process the inner surface of the cylinder to a certain depth using a grinder.In this way, when the oil groove is processed by hand, a large diameter cylinder For the operator to enter the inside of the cylinder to make the process relatively easy, but for a relatively small diameter (about 600 mm or less) there is a problem that a lot of difficulties in the processing of the oil groove.

In consideration of the difficulty in machining the oil grooves as described above, a lot of researches have recently been conducted on the automatic processing of oil grooves by mounting a processing tool on the end of the robot arm. However, in the case of a cylindrical inner surface such as an engine cylinder, since the machining target surface is composed of circles, even if the robot end implements a circle by circular interpolation, it is difficult to produce an accurate circle according to the position accuracy of the robot, and the robot base Since the parallelism between the coordinates and the center axis of the engine cylinder could not be accurately matched, there were problems in controlling the position of the machining tool.

The present invention has been made in view of the above problems, and an object of the present invention is to mount an machining tool head having a machining tool on a robot arm to process oil grooves on an inner surface of a cylindrical material such as an engine cylinder, and the degree of machining It is to provide a sensing device for position correction of the machining tool for processing the oil groove on the inner surface of the cylinder to increase the height, and to provide more accurate information for generating the machining path of the machining tool head, and a method for correcting the position of the machining tool using the same.

The present invention to achieve the object as described above and to perform the problem for eliminating the conventional defects is equipped with a robot arm with a machining tool for machining the oil groove and a spindle motor for rotating the machining tool A displacement sensor installed in the processing tool head for moving the oil groove on the inner surface of the cylinder and measuring the height of the processing tool from the inner surface of the cylinder to provide information for height correction of the processing tool; And

When the machining tool head is moved along the machining path by the robot arm and the machining tool is positioned at the vertical upper portion of the oil hole formed in the cylinder, the image including the oil hole is photographed. Cylindrical inner surface provided with; a visual sensor that is installed on the processing tool head so that the center of the oil hole is located to measure the distance away from the center of the image of the oil hole actually photographed to provide information for position correction of the processing tool It features a sensing device for position correction of the processing tool for processing the oil groove.

In addition, the present invention is equipped with a machining tool for the processing of the oil groove and the spindle motor for rotating the machining tool mounted on the robot arm is moved along the machining path by the robot arm and processing the oil groove on the cylinder inner surface In correcting the position of the processing tool by using a sensing device composed of a displacement sensor and a visual sensor installed in the head,

Measuring the height of the processing tool from the inner surface of the cylinder by using the displacement sensor when the processing tool head moves along the processing path and is positioned at a vertical upper portion of the oil hole formed in the cylinder (S2);

If there is a difference between the height of the machining tool measured from the step S2 and the height of the predetermined machining tool, correcting the height of the machining tool and correcting the machining path by moving the machining tool head by a difference value (S3);

Using the visual sensor set so that the center of the oil hole according to the design criteria is located at the center of the image to be photographed, the image including the oil hole is photographed, and the distance of the center of the oil hole of the actually photographed image is deviated from the center of the image. Calculating step S4; And

Determining whether the distance calculated from the step S4 is within a tolerance range (S5);

If the calculated distance is outside the tolerance range, correcting the position of the machining tool head and correcting the machining path based on the calculated distance (S6);

If the calculated distance is within the tolerance range, moving the machining tool head to position the machining tool to the position of the next oil hole (S7); And

After the movement of the processing tool head is made by the step S7, check whether the oil hole is the last, and if not the last oil hole, repeating from the step S2, and ending the correction process if the last oil hole (S8); Characterized in the position correction method using a sensing device for position correction of the processing tool for processing the oil groove on the inner cylinder made.

According to the present invention having the above characteristics, in machining the oil groove on the inner surface of the cylinder to accurately generate the processing path of the processing tool head to increase the precision of the machining, the automation rate when processing the oil groove on the inner surface of the cylindrical material such as engine cylinder You can increase the.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, if it is determined that the detailed description of the related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

Figure 2 shows a side view showing a state in which a processing tool head having a sensing device according to the present invention installed on the robot arm, Figure 3 shows a perspective view showing a state in which the sensing device according to the present invention is installed on the processing tool head have. On the other hand, in the sensing device 110 according to the present invention, the machining tool head 100 mounted on the robot arm 120 moves accurately along a predetermined machining path to automatically process oil grooves on an inner surface of a cylindrical material such as an engine cylinder. And to provide information for the position correction of the processing tool head 100 and the correction of the processing path to perform the processing, it comprises a displacement sensor 111 and the visual sensor 112. At this time, the displacement sensor 111 measures the height from the inner surface of the cylinder to provide information to the processing tool head 100 to maintain a constant height from the inner surface of the cylinder, the visual sensor 112 is oil formed on the inner surface of the cylinder By detecting the position of the machining tool head 100 on the basis of the hole to provide information for the position correction of the machining tool head 100.

The machining tool head 100 having the machining tool 102 for machining the oil groove and the spindle motor 101 for rotating the machining tool 102 is mounted on the robot arm 120 to mount the oil groove on the inner surface of the cylinder. In order to automatically process the machining tool head 100 according to the structure of the oil holes formed in the inner surface of the cylinder and the oil groove connecting them so that the machining tool head 100 moves along a predetermined machining path and performs the machining. The preparation of the robot arm operating program for proper movement must be preceded.

Therefore, the operator writes the robot arm operation program considering the position of the oil holes and the structure of the oil groove. The robot arm 120 operates according to the operation program created as described above, and moves the machining tool head 100 along a predetermined machining path, and there are various factors such as mechanical errors or errors occurring in the setting process even when the machining is performed. Error occurs. Accordingly, the present invention detects the information for height and position correction of the processing tool head 100 by using the displacement sensor 111 and the visual sensor 112, and based on the height and position of the processing tool head 100 In addition to the correction, the machining path is modified.

As described above, the displacement sensor 111 and the visual sensor 112 that provide information for height and position correction of the processing tool 102 are installed in the processing tool head 100, and thus the displacement sensor 111 and the visual sensor. In installing the 112 to the processing tool head 100, the center of the displacement sensor 111 and the visual sensor 112 is in the Ty axis direction from the center of the spindle motor 101 provided in the processing tool head 100. It is installed to be located on the extending line (L). Here, the Ty axis direction means an axial direction located in the longitudinal direction of the cylindrical material during the processing of the oil groove. This is because the machining tool head 100 moves in the circumferential direction of the cylindrical material during machining of the oil groove, so that if the displacement sensor 111 and the visual sensor 112 are installed in the Tx axis direction perpendicular to the Ty axis, The value detected from the displacement sensor 111 and the visual sensor 112 should be calculated in consideration of the curvature of the circle. If the diameter of the member changes, the program must be modified according to the curvature of the circle. Because every time you have to go through a very cumbersome process.

In addition, when the visual sensor 112 is installed in the processing tool head 100, the processing tool head 100 moves along the processing path so that the processing tool 102 is positioned vertically above the oil hole. The image including the hole is taken, but the center of the oil hole according to the design criteria is set at the center of the image to be photographed. When the oil hole is photographed at the center of the image captured by the visual sensor 112, it is determined that the processing tool head 100 moved along the machining path is moved to the correct position without error. When the oil hole is out of the center, to calculate the center distance of the oil hole from the center of the image to provide information for the position correction of the machining tool (102).

Figure 4 shows a flow chart showing the height and position correction process of the processing tool head using the sensing device according to the present invention.

The height and position correction of the processing tool head 100 according to the present invention is based on the oil hole formed in the cylinder, and for this purpose, the processing tool head according to the processing path such that the processing tool 102 is positioned on the vertical upper portion of the initial oil hole ( 100 is moved (S1). The movement of the processing tool head 100 is performed by an operation program input to a robot controller, which is prepared in advance and not shown.

When the processing tool 102 is located in the vertical upper portion of the first oil hole as described above, the displacement sensor 111 measures the height of the processing tool 102 from the inner surface of the cylinder (S2). In this case, since the displacement sensor 111 and the processing tool 102 always have a constant height difference, when the displacement sensor 111 detects the height from the inner surface of the cylinder, the height of the processing tool 102 can be known.

As described above, when the height of the machining tool 102 detected from the displacement sensor 111 is different from the height of the predetermined machining tool 102, the machining tool head 100 is moved in the Tz axis direction by the difference value. The height of the machining tool 102 is corrected and the machining path is corrected (S3).

Next, the visual sensor 112 captures an image including the oil hole, and calculates a distance from the center of the oil hole of the captured image to the center of the image. For a more detailed description, referring to FIG. 5, which shows a state when the oil hole is out of the center of the image, the visual sensor 112 has a processing tool 102 at a vertical upper portion of the oil hole as described above. When it is positioned, since the center of the oil hole 201 according to the design criteria is set to be located in the center of the image is installed in the processing tool head 100, the photographed oil hole 202 from the center of the image Tx and Detecting how far in the direction of the Ty axis, it is possible to provide information for the position correction of the machining tool head 100.

On the other hand, when the focal length (the distance between the image pickup device and the subject) is constant, the camera constituting the visual sensor 112 may convert the pixel unit of the captured image into the physical distance (mm). Therefore, in the present invention, the visual sensor 112 is always maintained at a constant height from the inner surface of the cylinder by the height information measured from the displacement sensor 111, and the image is taken in this state, so that the oil hole from the center of the captured image The distance outside 202 is converted into a physical distance (mm) and used as information for position correction of the processing tool head 100. Here, the recognition of the center of the oil hole from the captured image and the calculation of the distance from the center of the oil hole to the center of the oil hole can be implemented in various ways using various known algorithms, and thus, a detailed description thereof will be omitted.

On the other hand, through the image analysis taken by the visual sensor 112 as described above it is determined whether the processing tool 102 is in the error range or out of the error range (S5).

If the calculated distance is within the tolerance range, the machining tool head 100 is moved to the position of the next oil hole (S7). If the calculated distance is out of the tolerance range, the machining is performed based on the calculated distance. The position of the tool head 100 is corrected and the machining path is corrected (S6). As such, after the position correction of the processing tool head 100 is performed, the processing tool head 100 may be moved to the position of the next oil hole, but the feedback step (S6-1) for more accurate positioning of the processing tool head 100. This feedback step (S6-1) is performed by repeating again from step S4 so as to detect the position of the machining tool head 100 moved by correction by going back to step S4. .

On the other hand, when the processing tool head 100 is moved to the position of the next oil hole through the step S7, it is checked whether the oil hole is the last oil hole from the operation program, and if the oil hole is not the last oil hole, the step S2 Repeated from, and if the last oil hole to complete the calibration process (S8).

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes will fall within the scope of the claims.

1 is an exemplary view showing an example of an oil groove formed on an inner surface of an engine cylinder;

2 is a side view showing a state in which a processing tool head having a sensing device according to the present invention is installed on a robot arm;

Figure 3 is a perspective view showing a state in which the sensing device according to the present invention is installed on the processing tool head,

Figure 4 is a flow chart showing the height and position correction process of the processing tool head using a sensing device according to the present invention,

5 is a state diagram when the oil hole is out of the center of the image in the image captured by the visual sensor of the present invention.

<Explanation of symbols for the main parts of the drawings>

(100): Machining tool head (101): Spindle motor

(102): machining tool (111): displacement sensor

(112): Vision sensor 120: Robot arm

Claims (4)

With a machining tool 102 for machining oil grooves and a spindle motor 101 for rotating the machining tool 102 mounted on the robot arm 120 and moved by the robot arm 120 on the inner surface of the cylinder. It is installed in the processing tool head 100 for processing the oil groove, and is installed on the line (L) extending from the center of the spindle motor 101 in the Ty axis direction parallel to the longitudinal direction of the cylinder from the inner surface of the cylinder. A displacement sensor 111 that measures the height of the machining tool 102 and provides information for height correction of the machining tool 102; And When the machining tool head 100 is moved along the machining path by the robot arm 120 and the machining tool 102 is positioned at the vertical upper portion of the oil hole formed in the cylinder, the image including the oil hole is photographed. Line installed in the machining tool head 100 so that the center of the oil hole according to the design criteria is located in the center of the image to be photographed, and extends in the Ty axis direction parallel to the longitudinal direction of the cylinder from the center of the spindle motor 101 (L And a visual sensor 112 that measures the distance from the center of the oil hole of the image to be actually photographed and is taken from the center of the image to provide information for correcting the position of the processing tool 102. Sensing device for position correction of machining tools that process oil grooves on the inner surface of a cylinder. delete A machining tool 102 for machining an oil groove and a spindle motor 101 for rotating the machining tool 102 are mounted on the robot arm 120 and moved along the machining path by the robot arm 120. And in correcting the position of the machining tool 102 by using a sensing device 110 consisting of a displacement sensor 111 and a visual sensor 112 installed in the machining tool head 100 for processing oil grooves on the inner surface of the cylinder, When the machining tool head 100 moves along the machining path and the machining tool 102 is positioned at the vertical upper portion of the oil hole formed in the cylinder, the displacement tool 111 is used to determine the machining tool 102 from the inner surface of the cylinder. Measuring the height (S2); If there is a difference between the height of the machining tool 102 and the height of the predetermined machining tool 102 measured from the step S2, the height of the machining tool 102 is corrected by moving the machining tool head 100 by the difference value. And correcting the processing path (S3); Using the visual sensor 112 set so that the center of the oil hole according to the design criteria is located at the center of the image to be photographed, the image including the oil hole is photographed, and the center of the oil hole of the actually captured image is from the center of the image. Calculating a deviation distance (S4); And Determining whether the distance calculated from the step S4 is within a tolerance range (S5); If the calculated distance is outside the tolerance range, correcting the position of the machining tool head 100 and correcting the machining path based on the calculated distance (S6); If the calculated distance is within the tolerance range, moving the machining tool head 100 to position the machining tool 102 to the position of the next oil hole (S7); And After the movement of the processing tool head 100 is performed by the step S7, check whether the corresponding oil hole is the last, and if not the last oil hole, repeating from the step S2, and ending the correction process if the last oil hole (S8). Position correction method using a sensing device for position correction of the processing tool for processing the oil groove on the inner surface of the cylinder, characterized in that consisting of. The method of claim 3, wherein If the position correction of the processing tool head 100 is made in step S6, the position of the processing tool for processing oil grooves on the inner surface of the cylinder, characterized in that it further comprises a feedback step (S6-1) to repeat from the step S4 Position correction method using the correction sensing device.

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