JP2507042Y2 - Grinding wheel measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a grindstone measuring device capable of measuring the shape of a grinding surface portion of a grindstone of a grinder by NC control with high accuracy, for example.

[Conventional technology]

Since the grinding wheel used in the NC grinder requires high grinding accuracy, the surface shape of the grinding surface is strictly checked. The cross section of the ground surface when the grinding wheel is cut in the radial direction including the center thereof has a curved surface shape in which the tip side is arcuate, and the surface is set to be a perfect circle. When grinding the workpiece, the grinding surface of the grinding wheel gradually wears away, so it is necessary to check the grinding surface regularly.In the past, it was possible to enlarge the size with a projector and visually check it. It is being appreciated.

However, with this method, accurate arc radius values and center positions cannot be obtained, and if the shape accuracy of the workpiece that has undergone contour grinding decreases, and if these values deviate, a function to correct them is provided. There was a problem that it was not possible to input the data directly into the NC grinder and make the necessary corrections.

On the other hand, Japanese Unexamined Patent Publication No. 62-157773 proposes a device for measuring the shape of a ground surface by providing a detecting means for contacting a grindstone to detect the position of a contact point. The detection means uses a piezoelectric element.The sensor detects the vibration when the surface of the grinding wheel hits and inputs it to the arithmetic circuit of the control unit to calculate the radius of the grinding surface and its center position. ,
Control is performed to reset the axis of the grinding wheel by comparing it with a preset reference value.

In this device, in order to measure the radius of the arc surface and the center position thereof, the detecting means is brought into contact with the most distal end of the arc cross section and three points on both sides thereof, and the measured value is calculated from these values.
The detecting means is connected to a mechanism for turning around the tip of the grinding wheel in order to contact the grinding wheel at three points.

[Problems to be solved by the device]

By feeding back the measurement result obtained by such a contact type measurement to the NC control device, the correction function of the NC grinder can be effectively utilized.

However, at the time of measurement, it is important not to shift the contact position of the detecting means with respect to the grinding wheel.
For this reason, high precision is also required for the mechanism itself for rotating the detecting means, which complicates the mechanism and inevitably increases the size of the device. Further, in precision surface processing, the accuracy of the surface has a great influence on the product. Therefore, the malfunction of the swivel mechanism or the operation including an error adversely affects not only the measurement failure but also the machining of the work. For example, even if the conditions such as temperature and humidity change, from the viewpoint of precision processing, the rotation stop accuracy and positioning accuracy of the swivel mechanism increase the measurement error, so the reliability of the correction value to the NC grinder is not high. It was

The problem to be solved in the present invention is to make it possible to measure the grinding surface of a grinding wheel with a simple structure and high accuracy.

[Means for solving the problem]

The present invention is provided on a table of a grinder, and grinds the grindstone by detecting the shape of the grind surface with respect to a grindstone whose ground surface is formed into an arcuate cross-sectional shape, and detecting three positions of different arc surfaces. A measuring device that measures by calculating the size of the center and radius of the surface, the measuring device detecting the detection block contacting the arc-shaped grinding surface of the grindstone, and detecting the vibration received by the detection block. A detection unit for inputting a signal to a control unit that executes the calculation, wherein the detection block is
A flat part that comes into contact with the tip of the grinding surface is formed so as to have a convex shape at the upper end, and a slope that has a downward slope from both sides of the flat part and that comes into contact with two points apart from the tip of the grinding surface. And the shape of each of the flat surface portion and the inclined portion and the position of the detection block are stored in the arithmetic system of the control unit as known in advance, and the flat surface portion and the left and right inclined portions are used to store the grinding surface. The outer diameter and the central position of the grinding surface can be calculated by the control unit by detecting the positions of three different points on the ground surface when the grinding surface is cut along a plane orthogonal to the axis line.

[Action]

Since the detection block has a flat portion and a pair of inclined portions as the contact surface with the grinding surface of the grindstone, if the table is moved to change the contact point, the detection block does not have to change its posture and has an arc-shaped cross section. Can be brought into contact with three points on the ground surface. For this reason, a mechanism for rotating the detection block is not required, and it is possible to measure the ground surface with high accuracy with a simple structure.

Further, the position and the upper end surface of the detection block are made convex and this portion is made into a flat surface portion, and the respective shapes of the inclined surfaces having a downward slope at both end portions are stored in the arithmetic system of the control portion as pre-specified. By doing so, the relative positional relationship between the grindstone and the detection block can be set in advance. Therefore, the center position and the size of the outer diameter calculated based on the relationship between the three positions of the grinding surface detected by the flat surface portion and the inclined surface, for example, the grinding surface of the grindstone stored in advance in the arithmetic system. The shape of the ground surface can be determined by performing a comparison calculation with the center position and outer diameter when is a perfect circle.

〔Example〕

FIG. 1 is a front view of an NC-controlled grinding machine equipped with the measuring device of the present invention, FIG. 2 is a side view, and FIG. 3 is a plan view of the measuring device portion.

In the figure, the grinder is the same base as the conventional one.
20, a saddle 21 and a table 22 are provided, and a jig 23 for holding and fixing the work is arranged on the table 22. The saddle 21 reciprocates in the direction of the arrow in FIG.
The table 22 reciprocates in the direction of the arrow in FIG. 2, and the combination of these operations causes the table 22 to make a two-dimensional plane motion.

The grindstone 10 is supported by a column (not shown) that is raised from the base 20 and fixed so as to be movable only in the vertical direction, and its rotation axis is parallel to the moving direction of the saddle 21 and orthogonal to the moving direction of the table 22. There is. The measuring device 1 for measuring the grinding surface of the grindstone 10 is arranged at one end of the base 22 separated from the jig 23. A blower 24 blows air toward the measuring device 1 and is used to remove the polishing powder when the grindstone 10 kept rotating during the measurement is brought into contact with the detection block 3.

The measuring device 1 is composed of a detector 2 that outputs a signal using a piezoelectric element and a detection block 3 that contacts the grindstone 10. In the detector 2, the detection block 3 has a grindstone 10
The piezoelectric element responds to the vibration when it comes into contact with, and inputs a signal to the control section of the NC grinder. Also, the detection block 3
As shown in FIG. 1, the flat portion 3a is formed on the side contacting the grindstone 10 and the inclined portions 3b, 3c are formed on both sides thereof. The inclination and the surface shape of the inclined portion 3b are formed with a high precision value, and the radius and center position of the arc of the tip of the grindstone 10 are calculated by presetting this inclination.

In the above-described configuration, the grinding surface of the grindstone 10 is measured periodically during the grinding process on a regular basis or on the basis of the cumulative number of revolutions of the grindstone 10, or the like. The point is Table 22
2 is moved to the left side in FIG. 2, and the measuring device 1 is set at the measuring position with respect to the grindstone 10 which is absolutely stationary with respect to the table 22. The grindstone 10 is still rotating during the measurement. Then, for the detection block 3, the grindstone 10
By moving the saddle 21 so that the arcuate portion 10a at the tip of the contact the inclined portion 3b, the flat surface portion 3a and the inclined portion 3c in this order,
Change the position of the table 22 in the axial direction of 10. These three
The value obtained from the contact position at the point is calculated by the control of the NC grinder to calculate the correction amount of the position of the grindstone 10.

In this measurement, first, as shown in FIG. 4 (a), the inclined portion 3b is set so as to be below the grindstone 10, and then the grindstone 10 is lowered by using the mechanism of the column. By this operation, the circular arc portion 10a of the grindstone 10 comes into contact with a predetermined position of the inclined portion 3b of the detection block 3, and the detector 2 outputs a signal due to the vibration at this time. This signal is input to the control unit of the NC grinder and the coordinates of the position of the reference table 22 before measurement and the position of the detection block 3 and the position of the axis of the grindstone 10 after the movement with respect to the height of the axis of the grindstone 10. Is read. Further, in the same manner, as shown in FIGS. 4 (b) and 4 (c), the arcuate portion 10a of the grindstone 10 is brought into contact with the flat surface portion 3a and the other inclined portion 3c, and the similar position of the table 22 and the grindstone 10 are moved. Have the controller of the NC grinder read the coordinate of the height of the shaft center.

Based on the contact positions at these three points and the inclination angles of the inclined portions 3b and 3c, the radius of the arc portion 10a and its center point position when the arc portion 10a of the grindstone 10 is formed into a perfect circle shape And are calculated by calculation in the control unit. The calculated radius of the arc portion 10a and the deviation of the center point position from the target value are calculated by the control unit of the NC grinder. As a result, when the grinding is started again, the setting of the position of the grindstone 10 in the up-down direction and the front-rear direction is corrected, and the grindstone 10 is set in a state in which its grinding surface appropriately contacts the workpiece.

Since the flat surface portion 3a and the inclined portions 3b and 3c of the detection block 3 are ground by the grindstone 10 at each measurement, the movement of the saddle 21 can be controlled so that the contact point is different for each measurement. preferable. Further, not only a grindstone having a ground surface having an arcuate cross section, but also a flat surface 3a of the detection block 3 can be used to measure a grindstone whose peripheral surface is a flat ground surface.

[Effect of device]

According to the present invention, the detection block that comes into contact with three different points on the grinding surface of the arcuate section of the grindstone has a flat surface portion and a pair of inclined portions, and the shape of the grinding surface can be measured by bringing these into contact with the grinding surface. . Therefore, a mechanism for changing the posture of the detection block and contacting the grinding surface at three different points is unnecessary, and a measuring device having a simple structure can be obtained. Further, since the mechanism for moving the detection block is not included, the assembling accuracy of the measuring apparatus itself is increased, and the accuracy is not deteriorated even under the conditions such as temperature, and the grinding surface can be always measured with high accuracy.

[Brief description of drawings]

FIG. 1 is a front view of an NC grinder equipped with the measuring device of the present invention,
FIG. 2 is a side view, FIG. 3 is a plan view of the measuring device portion, and FIG.
The figure is a diagram showing a measurement procedure by the detection block. 1: Measuring device, 2: Detector, 3: Detection block 3a: Flat part, 3b, 3c: Inclined part 10: Grindstone, 10a: Arc part, 20: Base 21: Saddle, 22: Table, 23: Jig 24 : Blower

Claims (1)

(57) [Scope of utility model registration request] 1. A grinder provided on a table of a grinder, the grinding surface of which is formed into an arcuate cross-sectional shape, the shape of the grinding surface, and the position of three different arc surfaces is detected to detect the position of the grindstone. A measuring device that measures by calculating the size of the center and radius of the grinding surface, wherein the measuring device detects a detection block that contacts the arc-shaped grinding surface of the grindstone, and detects the vibration received by the detection block. And a detector for inputting a signal to a control unit for executing the calculation, wherein the detection block is formed so that a flat surface portion in contact with a tip portion of the grinding surface is convex at an upper end, and the flat surface portion is formed. Slanted portions having a downward slope from both sides of the slanted surface and contacting two points distant from the tip of the grinding surface, respectively, and the shapes of the flat surface portion and the slanted portion and the position of the detection block are known in advance. Control The outer diameter and the central position of the grinding surface are detected by detecting the positions of three different points on the grinding surface when the cutting surface is cut by a plane orthogonal to the axis of the grinding surface by each of the flat surface portion and the left and right inclined portions. A grindstone measuring device for a grinding machine, characterized in that the control unit can calculate.