JPH0413559A - Automatic polishing device and method - Google Patents

Abstract

PURPOSE:To polish themmaterial to be worked with good accuracy by providing a distance sensor which detects the work quantity of a work face with the distance between the polished work face and sensor being measured. CONSTITUTION:The material 5 to be worked is fixed by a fixing mean after pressing a work face to the stopper 22 of a positioning mean 2 with fluid being blown to the material 5 to be worked from a fluid blowout hole from the opposite direction of the work face of the material 5 to be worked at a positioning station II. The work face of the material 5 is then polished by a polishing machine 3 having a moving device 33 at a polishing station III, the work face is detected by a distance sensor 4 at a detection station IV and the moving distance of a polishing machine 3 is controlled with the detected signal being led to the moving device 33 of the polishing machine 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention mainly relates to an automatic polishing device and a polishing method for polishing the sprue of a lost wax precision casting.

[Conventional technology]

Polishing the sprue of a lost wax precision casting product involves separating the product, which is assembled radially from the runner, from the sprue, and polishing the sprue remaining in the product using a polishing machine such as a belt grinder or a whetstone.

The surface of the sprue part of the product separated from the runner channel has an uneven shape with locally sharp parts, which tends to cause variations in the amount of polishing. A grinding device is disclosed. This is a device that applies a distance sensor directly to the grinding surface of the material to be ground, and controls the position of the grinder based on the distance signal. However, in the case of the shape of the sprue cut surface as described above, even if a distance sensor is applied, the distance accuracy cannot be obtained, so the required polishing accuracy cannot be satisfied. Further, errors in the outer diameter of the product also cause errors in the positioning accuracy of the workpiece, which in turn causes variations in the polishing accuracy of the sprue.

For this reason, conventional sprue polishing has been a process of manually holding the product and pressing the sprue against a polishing machine to polish it, which is labor-intensive, and there has been a strong desire to automate the polishing process.

[Problems to be Solved by the Invention] When polishing the sprue of a precision cast product using a conventional polishing device, as mentioned above, the accuracy of the cut sprue surface may be poor, or the external dimensions of the precision cast product may be inaccurate. If the error is large,
This also causes errors in the positioning accuracy of the product, which in turn affects the polishing accuracy of the sprue.

In addition, the grindstone and blades of the polishing machine wear out when polished repeatedly, which affects the polishing accuracy of the sprue. Therefore, it is necessary to correct these factors that affect polishing accuracy.

In view of the above problems, the present invention positions a workpiece without being affected by errors in the sprue surface or dimensions of the workpiece, and
It is an object of the present invention to provide an automatic polishing device and an automatic polishing method that accurately grasp the wear amount of a grindstone and cutter after polishing and maintain constant polishing accuracy of a sprue.

[Means for solving problems]

The present invention has a shape part larger than the workpiece, the workpiece is loosely fitted with the workpiece protruding from the mold part, and positioned by spraying fluid from a direction perpendicularly opposite to the workpiece. a positioning jig, a positioning means having a stopper for positioning the workpiece by pressing against it, a fixing means for fixing the positioned workpiece, and controlling the amount of processing of the workpiece. Automatic polishing comprising: a polishing machine having a moving device and polishing the processed surface; and a distance sensor measuring the distance between the polished processed surface and the sensor to detect the amount of processing on the processed surface. It is a device.

Furthermore, a supply station, a positioning station, a polishing station, and a detection station for the workpiece are arranged at equal intervals in the circumferential direction, and the processing surface of the workpiece protrudes from the end surface of the positioning jig at the supply station. At the positioning station, fluid is blown onto the workpiece from the fluid outlet from the direction opposite to the workpiece surface, and after pressing the workpiece surface against the stopper of the positioning means, the workpiece is The material is fixed by a fixing means,
At the polishing station, the processed surface of the workpiece is polished by a polishing machine having a moving device, at the detection station, the processed surface is detected by a distance sensor, and the detected signal is introduced into the moving device of the polishing machine. This is an automatic polishing method characterized by controlling the moving distance of the polishing machine.

In the present invention, the mold part provided on the positioning jig for positioning the workpiece must be larger in size than the workpiece because the workpiece is normally fed manually.

However, if the difference between the dimensions of the workpiece and the mold part is too large, errors will likely occur in the positioning of the workpiece, and if it is too small, it will be difficult to supply and discharge the workpiece.

Therefore, the above-mentioned mold part is 0.01 to 3.
It is desirable that the size is about 0 mm larger.

Further, the remaining amount of the sprue after polishing may be set to 0 depending on the use of the product, or may be left so as to protrude up to about 0.5 mm from the product surface.

〔Example〕

Next, the present invention will be explained in detail based on examples and drawings.

FIG. 1 is a plan view showing an embodiment of the automatic polishing apparatus of the present invention, FIG. 2 is a side view thereof, FIG. 3 is a plan view showing a situation in which a workpiece 5 is positioned and fixed, and FIG. FIG. Figure 5 shows the signal from the distance sensor 4 that drives the servo motor 32.3.
6 is a diagram showing the amount remaining in the sprue, and FIG. 7 is a flowchart showing a circuit for determining the amount remaining in the sprue.

A circular table 1 has a workpiece positioning jig 1 on its upper surface.
A clamp 12 for fixing the clamp 1 and the workpiece 5 is arranged, and is rotated by a motor 13 at 90° intervals in the direction of the arrow.

The positioning jig 11 has a supply station I for the workpiece 5.
Then, the workpiece 5 is manually inserted into a mold whose dimensions are larger than the external dimensions of the workpiece 5, with the sprue 51 directed toward the outside of the circular table l.

This work may be performed using an automatic feeding device that combines a parts feeder, a magazine, and a transfer device. At the next positioning station ■, compressed air for extruding the workpiece as shown in FIGS. 6 is used to press the reference surface 52 of the workpiece 5 against the stopper 22 for positioning, and then fixed by the clamp 12.

In the polishing station (2), the sprue portion 51 of the fixedly positioned workpiece 5 is polished by a polishing machine. The fourth station is a detection station ■ that detects the amount remaining in the sprue after polishing with a distance sensor 4, and a servo motor 32 that moves the polishing machine 3 back and forth and left and right based on the detection signal.
．． Activate 33. After detecting the amount remaining in the sprue, the workpiece 5
The workpiece 5 is discharged from the positioning jig 11 by blowing compressed air onto the positioning jig 11.

Next, the workpiece positioning fixture 11 will be explained in more detail with reference to FIGS. 3 and 4.

First, the structure of the jig 11 will be explained. This positioning jig has a structure similar to that of three stacked plates, and is provided with a passage for compressed air. A mold portion slightly larger than the workpiece 5 is machined on the central plate 11a, and the workpiece 5 is set into this mold.

When changing the shape and dimensions of the workpiece, it is only necessary to replace the central plate 11a, which has the optimum mold section, depending on the situation of the workpiece. Further, the dimensional difference between the workpiece and the die is set such that the die is 0.01 to 3.0 mm larger than the die, and is set to an optimum size difference depending on the situation of the workpiece.

The stopper 22 placed on the upper part of the air cylinder 21 is advanced from the direction perpendicular to the processing reference surface 52 of the workpiece 5. At this time, the processing reference surface 52 and the contact surface of the stopper 22 do not yet come into contact with each other. Next, compressed air 6 whose pressure and flow rate have been adjusted is blown onto the workpiece 5 from a hole provided in the positioning jig 11 in a direction perpendicularly opposite to the workpiece processing reference surface 52, and the force of the compressed air is used to set the processing standard. Positioning is performed by pressing the surface 52 against the stopper 22. Immediately after that, the workpiece 5 is pressed and fixed by a flat clamp 12 provided above the workpiece 5. After fixing the workpiece, the stopper 22 returns to its original state.

Next, a method for correcting the position of the polishing machine 3 will be explained with reference to FIGS. 5, 6, and 7. The explanation will be made according to the flowchart shown in FIG. First, the sprue portion 51 of the workpiece 5 after polishing is detected by the distance sensor 4, and the amount remaining at the sprue is sent via the amplifier 70 to the comparison discriminators 71 and 72 (step 80). An upper limit value and a lower limit value are set in the comparison discriminators 71 and 72 in order to discriminate the amount of remaining polishing of the sprue. As illustrated in FIG.
The upper and lower limits of the range (2) are set in the comparison discriminator 72.

Next, the remaining amount of sprue from the distance sensor 4 is input to the comparison/discriminator 71 and compared with the value in the range ■ (step 81
). This result is output to the controller 73. If it is outside the range ■ (range ■), proceed to step 82 and controller 7
A device stop command is output from step 3.

This may be due to an abnormality such as excessive wear or breakage of the belt 31, so the apparatus is stopped for confirmation. If it is within the range ■, the process proceeds to step 83, where the comparison/discriminator 72 compares and determines the ranges ■ and ■ (step 83) and inputs the result to the controller. If it is in the range ■, there is no abnormality, so the process advances to step 88 to perform polishing work.

If the range is δ, it is assumed that there is local wear on the polishing belt 3I, and the process proceeds to step 84, where the polishing machine 3 is shifted to the left by the servo motor 32 by the amount of feed set by the belt lateral feed position setting device 74. The amount of horizontal movement of the servo motor 32 is set to the same width as the polishing belt 31. Next, it is checked with the Mitsutswitch whether the position of the polishing belt 31 has not reached the left limit (step 85). If the left limit has not been reached, the process proceeds to step 88 to perform polishing work, and if the left limit has been reached, the polisher is shifted in the opposite direction to the right limit.
Step 86). In this way, the entire surface of the polishing belt 31 in the width direction can be used to achieve a uniform abrasion state.

Next, the forward cutting position of the polishing machine 3 is corrected by the value of the cutting amount set by the cutting amount setting device 75 of the belt 31 (step 87), and then the servo motor 33, the polishing machine 3 is advanced to perform polishing work (step 88).

In this way, the sprue 51 of the workpiece 5 can always be polished in a constant state.

Although the embodiments described above mainly use a polishing belt as a polishing machine, the present invention can also be applied to other polishing machines such as a grindstone.

[Effects of the Invention] As described above, according to the present invention, a workpiece can be polished with high precision without being affected by the dimensional error of the workpiece and the amount of wear of the polishing belt or grindstone.

Furthermore, by standardizing the jig for positioning the workpiece, the changeover time when changing the shape and dimensions of the workpiece can be shortened, making this invention very effective industrially.

[Brief explanation of the drawing]

Fig. 1 is a plan view of the automatic polishing apparatus of the present invention, Fig. 2 is a side view thereof, Fig. 3 is a plan view showing a situation in which a workpiece is positioned and fixed, Fig. 4 is a side view thereof, and Fig. 5 6 is a diagram showing a system for controlling the servo motors 32 and 33 with the signal from the distance sensor 4, FIG. 6 is a diagram showing the amount remaining in the sprue, and FIG. 7 is a flowchart showing a circuit for determining the amount remaining in the sprue. 1: Circular table, 11: Positioning jig, 12: Clamp, 13: Motor, 2: Positioning means. 21: Air cylinder, 22: Stopper, 3: Polishing machine,
31: Polishing belt 32. 33: Servo motor, 4: Distance sensor, 5: Workpiece material, 6: Compressed air I: Supply station, ■: Positioning station, ■
: Polishing station, ■: Detection station Fig. 1 Fig. 3 Cause Fig. 4 Fig. 5

Claims (1)

[Scope of Claims] 1. It has a shape part larger than the workpiece, and the machined surface of the workpiece protrudes from the mold part and is fitted loosely, and the fluid is supplied from a direction perpendicularly opposite to the machined surface. a positioning jig that positions the workpiece by spraying it with water, a positioning means having a stopper that positions the workpiece by pressing against it, a fixing means that fixes the positioned workpiece, and processing of the workpiece. It is characterized by comprising a polishing machine that has a moving device that controls the amount and polishes the processed surface, and a distance sensor that measures the distance between the polished processed surface and the sensor to detect the processed amount of the processed surface. Automatic polishing equipment. 2. A supply station, a positioning station, a polishing station, and a detection station for the workpiece are arranged at equal intervals in the circumferential direction, and the processing surface of the workpiece at the supply station protrudes from the end surface of the positioning jig. At the positioning station, fluid is blown onto the workpiece from the fluid outlet from the direction opposite to the workpiece surface, and after pressing the workpiece surface against the stopper of the positioning means, the workpiece is fixing the material by a fixing means, polishing the machined surface of the workpiece at the polishing station with a polishing machine having a moving device, and at the detection station,
An automatic polishing method characterized in that the processing surface is detected by a distance sensor, and the detected signal is further introduced into a moving device of the polishing machine to control the moving distance of the polishing machine.