JP6467685B2 - Grinder equipment - Google Patents

Description

  The present invention relates to a grinder device used for grinding such as deburring of a cast product.

  Conventionally, in a grinding machine that grinds a workpiece using a wheel grindstone, a technique for controlling the peripheral speed of the grindstone according to a change in the grindstone diameter due to wear is known (Patent Documents 1 and 2).

  Patent Document 1 includes a memory that stores an optimum grinding wheel peripheral speed set for each grinding processing mode and a current grinding wheel diameter, determines a grinding processing mode to be processed next from grinding data, and performs grinding from the memory. We propose the technology to select the optimum grinding wheel peripheral speed corresponding to the processing form, calculate the grinding wheel rotation speed from this grinding wheel circumferential speed and the current grinding wheel diameter, and control the grinding wheel rotation speed by the calculated grinding wheel rotation speed. ing. In addition, a technique has been proposed in which the difference between the outer diameter of the grindstone detected by the dresser and the dressing cutting amount is stored in the memory as the “current grindstone diameter”.

  In Patent Document 2, the number of workpieces polished is counted, and a value obtained by multiplying the counted value by a constant is subtracted from the initial wheel diameter to detect the wheel diameter, and the rotation of the motor with respect to the wheel diameter is detected. We have proposed a technique for controlling a variable motor so that the speed changes inversely.

Japanese Patent No. 2941026 Japanese Patent No. 2959993

  These conventional technologies are effective in processing sites where mass production of certain products is performed, such as processing sites where grinding is performed based on grinding data and processing sites where workpieces of the same shape are continuously ground. However, at the machining site where grinding and finishing of a small number of products of various types is performed, such a method of estimation from the data or estimation from the number of machining is not a technique for optimizing the grinding wheel rotation speed. It is enough.

  For this reason, it is difficult to apply these conventional techniques to a grinder apparatus used in a processing site for a small amount of various types of products.

  Accordingly, an object of the present invention is to provide a grinder apparatus that can perform a grinding operation at an optimum grindstone rotational speed even at a processing site for a small amount of various types of products.

The grinder apparatus of the present invention made to achieve the above object is a grinder apparatus comprising a control device for controlling the rotational speed of the motor in accordance with a change in the grindstone diameter of a wheel-type grindstone rotated by a motor. Furthermore, it is characterized by having the following configuration.
(1A) A laser distance sensor is installed on the inner side of the grindstone cover that covers the wheel-type grindstone so as to irradiate laser light toward the rotation center of the wheel-type grindstone, and the laser irradiated by the laser distance sensor It has measuring means for measuring the distance to the grindstone outer peripheral surface based on the reflected light of the light.
(1B) The control device includes a control condition storage unit that stores a correspondence relationship between a grindstone diameter and a motor rotation number for rotating the wheel-type grindstone at a constant peripheral speed as a control condition; An input means for inputting a measurement result, a grindstone diameter calculating means for calculating a current grindstone diameter based on the measurement result inputted from the input means, and the control based on the grindstone diameter calculated by the grindstone diameter calculating means Motor rotation number setting means for setting a rotation speed control condition for the motor with reference to the control condition stored in the condition storage means, and the motor drive circuit based on the rotation speed control condition set by the motor rotation speed setting means Output means for outputting a control signal.
(1C) A determination unit that includes a plurality of the laser distance measuring sensors and that determines whether or not an error between measurement results obtained by the plurality of laser distance sensors is within a predetermined value. In the determination result by the determination means, when it is determined that the error is within a predetermined value, a grindstone diameter is newly calculated, and when it is determined that the error is not within the predetermined value. It is configured as means for using the grinding wheel diameter calculated immediately before without calculating the grinding wheel diameter as a calculation result.

  The grinder apparatus of the present invention can accurately capture the state in which the outer peripheral surface of the grindstone being measured is worn as the work progresses by installing the laser distance sensor as shown in (1A). it can. Moreover, since it is measurement by contact, the control which presses a probe in order to measure the change of a grindstone diameter is also unnecessary. And according to the grinder apparatus of this invention, as a result of being able to measure the distance to a grindstone outer peripheral surface correctly, without applying extra force to the grindstone to be measured, it is possible to accurately measure the change in the grindstone diameter. it can.

  In addition, since the grinder device of the present invention also has the configuration (1B), the control device inputs the measured value measured with high accuracy from the input unit even during the grinding process as described above. In addition, the current wheel diameter is calculated by the wheel diameter calculating means, and the correspondence between the wheel diameter and the motor rotational speed for rotating the wheel stored in the control condition storage means at a constant peripheral speed is currently The rotation speed control condition for the motor is set by the motor rotation speed setting means, and a control signal is output from the output means to the motor drive circuit based on the rotation speed control condition. As a result, even if the grindstone is worn and the grindstone diameter changes, the grindstone can be driven under the condition that the peripheral speed is constant, and stable machining can be performed. In particular, when performing various grinding processes on various workpieces as in a processing site for a small amount of various types of products, the grinding operation can be performed with the grindstone rotating speed being optimal.

  In addition, the grinder apparatus of the present invention calculates the grinding wheel diameter newly when the error of the measurement result by the plurality of laser distance measuring sensors is within the predetermined value by the configuration of (1C), and the error is predetermined. If it does not fall within the value, the grindstone diameter calculated immediately before without newly calculating the grindstone diameter is used as the grindstone diameter for determining the rotational speed control condition. As a result, the outer peripheral surface of the grinding wheel exceeds the predetermined value due to the situation where correct measurement cannot be performed with the laser distance sensor due to dust generated by grinding work, the grinding wheel is partially recessed due to grinding work, or some abrasive grains fall off, etc. In the case where the diameter fluctuation occurs, the rotational speed control is executed without updating the grindstone diameter. As a result of performing the rotational speed control without updating the grindstone diameter, it is possible to realize a control that keeps the circumferential speed constant while ensuring safety without excessively increasing the circumferential speed of the grindstone.

Here, the grinder apparatus of the present invention may further include the following configuration.
(2) An arc-shaped grindstone cover that covers an upper part and a back surface of the wheel-type grindstone is provided with a flat portion that is orthogonal to a straight line extending radially from the center of the wheel-type grindstone, and the flat portion On the other hand, the plurality of laser distance measuring sensors are installed so as to be arranged in the circumferential direction of the wheel-type grindstone.

  With the configuration (2), a plurality of laser distance measuring sensors can be appropriately installed. As a result, it is possible to accurately determine whether or not a measurement error due to dust or the like having the configuration (1C) occurs.

These grinder apparatuses according to the present invention may further include the following configuration.
(3) When the grindstone diameter calculated by the grindstone diameter calculating means is equal to or less than a predetermined value, the motor rotation speed setting means sets the rotation speed control condition with the predetermined value as the grindstone diameter. It has a restriction means.

  By providing the configuration (3) as well, it is possible to prevent the occurrence of inconvenience when the rotational speed of the motor is excessively increased due to the control for keeping the peripheral speed constant.

These grinder apparatuses according to the present invention may further include the following configuration.
(4) The motor rotational speed setting means is configured as means for setting the motor rotational speed control condition so as to change the motor rotational speed when the measurement result changes by a predetermined amount or more.

  By providing the configuration (4), it is possible to stably carry out control for keeping the peripheral speed constant without causing a sensitive rotation speed fluctuation.

  ADVANTAGE OF THE INVENTION According to this invention, the grinder apparatus which can perform a grinding operation in the state with an optimal grindstone rotational speed also in the processing field of a small amount multi-product type product can be provided.

The grinder apparatus of Example 1 is shown, (A) is the perspective view seen from the right front, (B) is the perspective view seen from the left front. The grinder apparatus of Example 1 is shown, (A) is a front view, (B) is a rear view, (C) is a top view, (D) is a left view. The attached state of the laser distance sensor of the grinder apparatus of Example 1 is shown, (A) is a left side view of the state with the cover removed, and (B) is an enlarged view of the main part. The structure for the measurement and control of the grinder apparatus of Example 1 is shown, (A) is a principal part enlarged view of a measurement part, (B) is a schematic diagram of a control part. FIG. 5 is a flowchart illustrating an outline of an initial setting program, and FIG. 5B is a flowchart illustrating an outline of a control signal determination program. FIG. It is explanatory drawing which shows the progress of the control for the periphery speed constant which the control apparatus of the grinder apparatus of Example 1 performs.

  Embodiments of the present invention will be described based on examples.

  As shown in FIG. 1 (B), the grinder device 1 of the first embodiment is a wheel type that is covered with a grindstone cover 3 or 4 on the left side of the front surface of the housing 2 and is partly exposed to the front side. By pressing against the grindstone 5 while supporting the workpiece W on the work table 6, it is suitable for use in a processing site of a small quantity, multi-product type product that performs grinding work such as deburring of a cast product.

  As shown in FIGS. 1 to 3, the grinder device 1 has a long hole at the front side end of an arc-shaped grindstone cover 3 attached so as to cover the back side from the upper part to the lower part of the wheel-type grindstone 5. A front plate 7 slidable in the direction is attached. The front plate 7 is used to secure safety so that the clearance between the upper part of the grindstone is within a predetermined range by being slid in the vertical direction and fixed according to the grindstone diameter. In this embodiment, a wheel-type grindstone 5 having a grindstone diameter of 610 mm × thickness of 32 mm × mounting diameter of 50.8 mm is mounted, and when the grindstone diameter is reduced to some extent, the front plate 7 is lowered and the gap above the grindstone is placed. It is supposed to be used so that does not become too large.

  A motor for driving the wheel-type grindstone 5 is housed in the upper part on the back side of the housing 2 with the rotation axis directed rightward, and the main shaft 8 to which the rotation axis of the motor and the wheel-type grindstone 5 are attached. A V-belt that transmits power to the housing 2 is housed in a V-belt cover 9 on the upper right side of the housing 2.

  A control panel 11 having an input button and a display device is installed in the center of the upper front of the housing 2. The control panel 11 is an input device such as driving conditions for the control device housed in the lower part of the housing 2 and a display device such as the driving state of the control device.

  The arc-shaped grindstone cover 3 that covers the wheel-type grindstone 5 from the upper part to the lower surface to the lower part is formed with a flat portion 3 a that is orthogonal to a straight line extending in the radial direction from the center of the main shaft 2. A sensor bracket 30 in which two laser distance measuring sensors 31 and 32 are housed in the body 30a so as to be arranged in the circumferential direction of the wheel type grindstone 5 is attached to the flat portion 3a. As shown in FIG. 3B, the two laser distance measuring sensors 31 and 32 are installed so as to output laser irradiation light 31a and 32a in a direction toward the main shaft 2 perpendicular to the flat portion 3a. Yes. Since these laser irradiation lights 31a and 32a are output from the two laser distance measuring sensors 31 and 32 provided adjacent to each other in the circumferential direction of the grindstone, they reach when a new grindstone is just attached. The distance becomes equal. By providing the flat portion 3a on the grindstone cover 3, the two laser distance measuring sensors 31, 32 can be appropriately installed so that there is no measurement error in the initial stage.

  As shown in FIG. 4A, the laser irradiation lights 31a and 32a output from the two laser distance measuring sensors 31 and 32 are reflected by the reflected lights 31b and 32b reflected on the peripheral surface of the wheel-type grindstone 5, respectively. Then, the laser distance sensors 31 and 32 are returned. The distance L between the peripheral surface of the wheel-type grindstone 5 and the laser distance measuring sensors 31 and 32 can be measured by the time from when the laser irradiation lights 31a and 32a are output until the reflected lights 31b and 32b return. . Here, in this embodiment, the laser distance sensor 31 installed on the upper side in the figure is set as the main, the laser distance sensor 32 installed on the lower side in the figure is set as the sub, and the measured value by the laser distance sensor 31 is set. Various control processes are executed based on L1.

  As shown in FIG. 4 (B), the control device 40 housed in the housing 2 stores the correspondence between the grindstone diameter R and the motor rotational speed RPM for rotating the grindstone at a constant peripheral speed. A condition storage unit 41, an input unit 42 for inputting an actual measurement value Lnow by the laser distance measuring sensors 31, 32, and a grindstone diameter calculation unit for calculating a current grindstone diameter Rnow based on the actual measurement value Lnow input from the input unit 42. 43, a motor rotation number setting unit 44 that sets the motor rotation number RPMow by referring to the control condition storage unit 41 based on the grindstone diameter Rnow calculated by the grindstone diameter calculation unit 43, and a motor rotation number setting unit 44. And an output unit 45 that outputs a control signal CMND to the motor drive circuit 46 based on the motor speed RPMNnow.

  The control device 40 is configured by a computer including a CPU, a ROM, a RAM, a hard disk, and the like. Programs as shown in FIGS. 5A and 5B are preinstalled in the hard disk of the computer.

  When the operator attaches a new wheel-type grindstone 5 and instructs the initial setting, the initial setting program is executed. Thereby, in the control apparatus 40, as shown to FIG. 5 (A), the measured value L1 of the distance to the grindstone peripheral surface which the laser ranging sensor 31 measured is input (S10), and the measured value L1 is determined as a criterion. While setting to the value LA (S20), 610 mm is set as the rotation speed control diameter RA (S30).

  When the machining start is commanded, the control signal determination program is activated. This control signal determination program is configured as shown in FIG. 5B, and is repeatedly executed at predetermined intervals. First, the control device 40 reads the measured values L1 and L2 of the distance to the grinding wheel circumferential surface measured by both the main and sub laser distance measuring sensors 31 and 32 (S110). And it is determined whether the measurement error (L1-L2) by both sensors is smaller than predetermined value Xmm (S120).

  When the measurement error is within the predetermined value (S120: YES), the current grindstone diameter Rnow = RA− (LA−L1) is calculated based on the rotation speed control diameter RA, the determination reference value LA, and the actual measurement value L1. (S130). Then, it is determined whether or not the grinding wheel diameter reduction amount ΔR = (previous Rnow−Rnow) is equal to or greater than Ymm (S140).

  Since the grindstone diameter has not decreased immediately after the start of operation, S140 becomes “NO”, the control condition storage unit 41 is referred to at RA = 610 mm, and the motor rotation speed RPMMow corresponding to the grindstone diameter 610 mm is set (S170). The control signal CMND is output to the motor drive circuit 46. As a result, the wheel-type grindstone 5 starts to be driven at a predetermined peripheral speed.

  On the other hand, when it is determined that the grinding operation has progressed to some extent and the grinding wheel diameter reduction amount ΔR ≧ Ymm is satisfied (S140: YES), it is determined whether or not the current grinding wheel diameter Rnow is 455 mm or less (S150). ). At the beginning of grinding, S150 is “NO”, and the process proceeds to S160. In S160, the criterion for the grinding wheel diameter is updated to RA = RA−Ymm. Then, referring to the control condition storage unit 41, the motor rotational speed RPMMnow corresponding to the rotational speed control radius RA is set (s170), and the control signal CMND corresponding to the motor rotational speed RPMNow is output (S180). Thereby, the wheel type grindstone 5 can be driven at the same peripheral speed as that at the start of driving even when the grindstone diameter is reduced by Ymm. As a result, the operator can perform workpiece grinding with the same feeling as when driving is started.

  Until the grinding wheel progresses and the grindstone diameter Rnow becomes 455 mm or less (S150: NO), every time the grindstone diameter Rnow decreases by Ymm, the motor rotational speed RPMNow is updated and the operation at the constant peripheral speed is continued.

  When it is determined that the grinding operation has progressed considerably and the grindstone diameter Rnow has become 455 mm or less (S150: YES), the rotational speed control diameter RA is fixed to 455 mm (S190). After this, the peripheral speed gradually decreases as the grindstone diameter decreases, but the motor rotation speed does not become too high, and the grinding work with an emphasis on safety can be continued.

  Further, in this process, when the measurement error (L1-L2) of the actual measurement values L1, L2 does not stay within the predetermined value Xmm (S120: NO), the current grindstone diameter is not updated and the current value is directly updated. (S135). This is executed when a situation in which the grinding wheel diameter cannot be accurately measured due to the influence of dust or partial removal of abrasive grains occurs. By adding the process of proceeding from S120 to S135, the reliability of the grindstone diameter measurement by the laser distance measuring sensor 31 is improved, and safety-oriented operation is enabled.

  By executing the above program, as shown in FIG. 6, the control signal CMD to the motor drive circuit 46 is changed every time the grindstone diameter R decreases by Ymm, and the motor rotation speed RPM is determined by the control condition storage unit 41. In accordance with the control conditions, the rotation speed between the minimum rotation speed RPMmin corresponding to the grinding wheel diameter R = 610 mm and the maximum rotation speed RPMmax corresponding to the grinding wheel diameter R = 455 mm is rotated for each grinding wheel diameter reduction amount ΔR = Ymm. Stepwise rotational speed control that increases the number is executed. By controlling the rotational speed stepwise, it is possible to perform workpiece machining at a stable peripheral speed that does not hinder grinding without excessively reacting to the irregularities on the grindstone surface.

  In this embodiment, the value of “Y”, which becomes the increment of the rotation speed change, is set to 0.67 mm, which is a value obtained by equally dividing 230 during the reduction of the grindstone diameter from 610 mm to 455 mm. Further, “X” as a determination condition for the measurement error (L1−L2) by both the main and sub laser distance measuring sensors 31 and 32 is set to 20 times of Y≈13.48 mm. In this way, when the value of Y is made sufficiently small, and when the value of X is compared with the value of Y, a value that is 10 times or more (differing in order) is set, it becomes too sensitive to errors. Therefore, it is possible to control with an emphasis on the stability of the peripheral speed by smoothly changing the rotational speed.

  Further, in this embodiment, by using the wheel-type grindstone 5 having a grindstone diameter of 610 mm × thickness of 32 mm, it is possible to carry out processing without exchanging the grindstone for a long period of time until the grindstone diameter becomes 455 mm or less. Since the motor speed is controlled so as to have a constant peripheral speed, there is no sense of incongruity in workability during this long-term use. For a grindstone diameter of 455 mm or less, although the peripheral speed is reduced, it is limited to the maximum rotational speed RPMmax of the motor, so that the rotational speed does not become too fast, and stable machining can be executed safely. it can.

  In addition to being able to measure the grinding wheel diameter in contact with the laser range sensor, if there is a measurement error that exceeds a predetermined value using multiple laser range sensors, the motor speed should not be changed. Thus, it is possible to accurately prevent unstable control due to measurement errors caused by dust or partial removal of abrasive grains.

  Further, when installing the two laser distance measuring sensors 31, 32, a flat portion 3a is provided on a part of the arc-shaped grindstone cover 3, and the two laser distance measuring sensors 31, By installing the sensor bracket 30 through the sensor bracket 30 having the sensor body 30a for accommodating the sensor 32, it is possible to easily realize the sensor attachment with high accuracy.

  As mentioned above, although the Example of this invention was described, this invention is not limited to this, Of course, various forms can be employ | adopted within the range which does not deviate from the summary.

  For example, there may be three or more laser distance measuring sensors, and the installation locations may be separated. It should be noted that it is better to keep a plurality of installation locations close to each other as in the embodiment in that no attachment error occurs.

  It can be used in the field where grinding processing such as deburring of cast products is performed.

  DESCRIPTION OF SYMBOLS 1 ... Grinder apparatus, 2 ... Case, 3, 4 ... Grinding wheel cover, 3a ... Flat part, 5 ... Wheel type grindstone, 6 ... Work table, 7 ... Positive Face plate, 8 ... main shaft, 9 ... V belt cover, 11 ... control panel, 30 ... sensor bracket, 30a ... body, 31, 32 ... laser distance measuring sensor, 31a, 32a ... Laser irradiation light, 31b, 32b ... Reflected light, 40 ... Control device, 41 ... Control condition storage unit, 42 ... Input unit, 43 ... Grinding stone diameter calculation unit, 44 ... motor speed setting unit, 45 ... output unit, 46 ... motor drive circuit.

Claims (4)

A grinder apparatus comprising a controller for controlling the number of revolutions of the motor in accordance with a change in the wheel diameter of a wheel-type grindstone rotated by a motor. The grinder apparatus further comprises the following configuration. .
(1A) A laser distance sensor is installed on the inner side of the grindstone cover that covers the wheel-type grindstone so as to irradiate laser light toward the rotation center of the wheel-type grindstone, and the laser irradiated by the laser distance sensor It has measuring means for measuring the distance to the grindstone outer peripheral surface based on the reflected light of the light.
(1B) The control device includes a control condition storage unit that stores a correspondence relationship between a grindstone diameter and a motor rotation number for rotating the wheel-type grindstone at a constant peripheral speed as a control condition; An input means for inputting a measurement result, a grindstone diameter calculating means for calculating a current grindstone diameter based on the measurement result inputted from the input means, and the control based on the grindstone diameter calculated by the grindstone diameter calculating means Motor rotation number setting means for setting a rotation speed control condition for the motor with reference to the control condition stored in the condition storage means, and the motor drive circuit based on the rotation speed control condition set by the motor rotation speed setting means Output means for outputting a control signal.
(1C) A determination unit that includes a plurality of the laser distance measuring sensors and that determines whether or not an error between measurement results obtained by the plurality of laser distance sensors is within a predetermined value. In the determination result by the determination means, when it is determined that the error is within a predetermined value, a grindstone diameter is newly calculated, and when it is determined that the error is not within the predetermined value. It is configured as means for using the grinding wheel diameter calculated immediately before without calculating the grinding wheel diameter as a calculation result. The grinder device according to claim 1, further comprising the following configuration.
(2) An arc-shaped grindstone cover that covers an upper part and a back surface of the wheel-type grindstone is provided with a flat portion that is orthogonal to a straight line extending radially from the center of the wheel-type grindstone, and the flat portion On the other hand, the plurality of laser distance measuring sensors are installed so as to be arranged in the circumferential direction of the wheel-type grindstone. The grinder device according to claim 1, further comprising the following configuration.
(3) When the grindstone diameter calculated by the grindstone diameter calculating means is equal to or less than a predetermined value, the motor rotation speed setting means sets the rotation speed control condition with the predetermined value as the grindstone diameter. It has a restriction means. The grinder device according to any one of claims 1 to 3, further comprising the following configuration.
(4) The motor rotational speed setting means is configured as means for setting the motor rotational speed control condition so as to change the motor rotational speed when the measurement result changes by a predetermined amount or more.