JPH0938859A - Automatic grinding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently perform inner side grinding with high accuracy without requiring any skill and intuition by arranging a contact type sensor adjacent to a grinding tool supporting base on a table for NC lathe. SOLUTION: An inner diameter of a work 9 is measured by a contact type sensor 5 mounted in a table 2 and comparison operation and grinding by a finishing grinding wheel 4 are repeated until the diameter reaches to a final grinding target diameter in the same way as a grinding step by a rough grinding wheel 3 when the measured value does not reach the final grinding target inner diameter. However, in the grinding by the finishing grinding stone 4, when X axial direction present value of the grinding wheel is not more than about 0.01 than movement target value of the grinding wheel, difference between the movement target value of the finishing grinding wheel 4 and X axial direction present value of the grindstone is calculated and the table 2 is moved to X axial direction as much as the difference amount.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to an automatic grinding apparatus for grinding an inner surface of a cylindrical work.

[0002]

2. Description of the Related Art
To grind the inner surface of a cylindrical workpiece with high accuracy, rotate the workpiece with a rotary chuck and
(Hereinafter, referred to as Z-axis direction) and a grindstone is arranged on a table that is slidable in two directions of the X-axis direction orthogonal to the Z-axis, and the grindstone is applied to the inner surface of the work piece and moved in the axial direction of the work piece. ing.

In this case, even if it is guaranteed that the table slides in accordance with the set numerical value, the machine is left with high precision due to changes in the amount of wear of the grindstone, delicate bending of the shaft holding the grindstone, and the like. It is not possible. Therefore, immediately before the target value is reached, the grindstone is separated from the work, and while the rotation of the work is stopped, the inner diameter is measured by the dial gauge to know the remaining grinding amount, and the apparatus is restarted.
This manual inner diameter measurement is usually performed multiple times until the target value is reached, which requires the intuition and labor of a craftsman, requires skill, and has poor work efficiency.

A high-precision NC internal grinding machine, which has a function of detecting the amount of wear and runout of a grindstone and is capable of automatically correcting the sliding amount of a table and performing automatic internal grinding, has also appeared, but is very expensive. Therefore, it is difficult to introduce unless a large number of pieces are processed, such as one lot is in the thousands or tens of thousands. The present invention attaches a contact type sensor for inner diameter measurement to a relatively inexpensive NC lathe that does not have a function of automatically detecting the wear amount of a grindstone, and the inner diameter measurement, which is conventionally performed by an operator, is burdened on the sensor. Then, by repeating the calculation and the grinding based on the measurement result, it is intended to clarify a grinding device capable of efficiently performing highly accurate inner surface grinding without requiring skill and intuition.

[0005]

A grinding apparatus of the present invention is a work piece.
Rotating chuck (10) that grips and rotates (9), and chuck
A table for supporting a grinding tool that can slide in two directions, the Z-axis direction along the axis of (10) and the X-axis direction orthogonal to the Z-axis direction.
(2), motors (16) (17) for driving the table (2) in the Z-axis direction and the X-axis direction, an operation panel (6) for inputting machining data for the work (9), and an operation panel An NC lathe (1) having a control unit (7) which is operated based on an input signal from (6) and a signal from the outside and controls the motors (16) and (17), and an NC lathe.
On the grinding tool support table (27) on the table (2) of (1), the holder (33) which is connected to the motor (31) is detachably supported, and the rotary chuck (10) for supporting the work is attached. Adjacent to the grinding tool support stand (27) on the grindstone (3) arranged at the same height as the axis and parallel to the axis of the chuck (10), and on the table (2) of the NC lathe. And the detection shaft (51) is at the same height as the axis of the rotary chuck (10) and the chuck
It is parallel to the axis of (10) and is constituted by a contact sensor (5) for inputting a contact signal to the control section (7) of the NC lathe.

The control unit (7) stores a processing data, a storage unit (71), an operation unit (72) for performing an operation for controlling the table (2) based on the operation data, and an operation result based on the operation result. ,
The table (2) is equipped with a judgment part (73) that outputs a signal for control, and up to a preset diameter calculated in consideration of factors that cause excessive grinding, rather than calculated values such as the amount of runout due to overhang of the grindstone. If the grinding progresses, the grinding is automatically stopped, the contact sensor (5) is moved by the movement of the table (2), the diameter of the work (9) is measured, and the difference between the machining target value and the measured value is measured. Is stored in the storage unit (71), and after restarting grinding, the calculation unit
(72) compares the difference between the processing target value and the measured value with the grinding amount per grinding × grinding count each time grinding is performed, and the operator
The judgment is made by (<), and the grinding is repeated by the command from the judgment unit (73) until the calculated grinding amount reaches the processing target value. If the grinding amount reaches the processing target value by calculation, the grinding is stopped. The diameter of the work (9) is measured again by the contact type sensor (5) in the same manner as above, and if the measured value does not reach the processing target, the difference between the processing target value and the measured value is again stored in the storage unit (71). ), And grinding and measurement are continued in the same manner as above.

[0007]

[Operation and effect] The work (9) is set on the chuck (10) and the operation panel (6) is operated to input the processing data to the control unit (7). The work (9) is ground by the movement of the table (2) in the Z-axis direction and the X-axis direction. Considering the conditions that cause over-grinding, such as the amount of runout due to the overhang of the grindstone, and if grinding progresses to a preset diameter in the calculation, grinding is automatically interrupted, so set at this stage. The amount of grinding that exceeds the value is not performed. The contact type sensor (5) accurately and automatically measures the diameter of the grinding surface of the work (9). Based on this measurement value, the calculation unit (72) accurately calculates the grinding amount up to the processing target value, and restarts the grinding work. If the grinding progresses to the processing target value in the calculation, the grinding is stopped, the diameter of the ground surface is measured again by the contact type sensor (5) and compared with the processing target value. If the processing target value is not reached, Then, the grinding is restarted in the same manner as described above. The grinding and measurement are automatically performed until the measured value reaches the processing target value.

As described above, the automatic grinding apparatus of the present invention automatically measures the measurement conventionally performed by the operator using the movement of the table of the NC lathe, and based on this measured value, the machining is performed. Since grinding is automatically advanced until the target value is reached, it is possible to save labor for highly accurate grinding without requiring the intuition and skill of an operator as in the past. Also, table (2)
However, the grindstone (3) and the contact sensor (5) may be provided on the table (2) of a relatively inexpensive NC lathe that slides only in the Z-axis direction and the X-axis direction. Can be kept low.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the whole grinding apparatus, and FIG. 2 shows the essential parts thereof. The entire grinding mechanism is surrounded by a cover (12), and the cover (12) is provided with a working opening (13) with a lid (14) for replacement and maintenance of a work (9) and a grindstone. Has been. The grinding device is configured by disposing a rough whetstone (3), a finishing whetstone (4) and a contact type sensor (5) on a table (2) of an NC lathe (1).

The NC lathe (1) used in the embodiment is a base (1
A head (15) protruding from one end of (1) is provided with a chuck (10) for holding a work, and a base (11) has a table (2) slidable in a horizontal plane. The chuck (10) is connected to a rotation driving device (not shown) controlled by a control unit (7) described later and rotates at a high speed at a fixed position. Chuck (1
The reference numeral 0) is a well-known structure which detachably supports the cylindrical work (9) with its axis centered horizontally, and the axis center of the chuck (10) is naturally positioned horizontally.

In the following description, the direction along the axis of the chuck (10) will be referred to as the Z-axis direction, and the direction orthogonal to the Z-axis direction within the horizontal plane will be referred to as the X-axis direction. The front means the chuck (10) side when viewed from the table (2), and the rear means the opposite side. Table (2)
Is a lower slide base (21) arranged on the base (11) so as to be slidable in the Z-axis direction along the guide strips (23) (23), and on the lower slide base (21) in the X-axis direction. It is composed of an upper slide stand (22) slidably mounted on each slide stand (2
1) and 22) are connected to a drive device (not shown) using independent high precision control motors 16 and 17 as drive sources.

The upper slide base (22) has a sensor support base (2
6), a rough whetstone support stand (27) and a finishing whetstone support stand (28) are arranged side by side in the X-axis direction. On the front of the sensor support (26),
A contact sensor (5) (in the embodiment, model ZS20P-32S manufactured by Daishowa Seiki Co., Ltd. is used) is attached. The sensor (5) has a cylindrical main body (52) provided with a detection shaft (51) protruding therefrom, and a spherical contactor (50) at the tip of the shaft (51). The NC lathe (numerical control lathe) through the amplification unit (55) described later by touching the measurement surface.
A signal is input to the control unit (7) of (1).

A cover (53) for protecting the contact type sensor (5) is provided on the upper surface of the sensor support (26) so that it can be undulated, and an undulation cylinder (54) is connected to the cover (53). ing. The cylinder (54) is automatically controlled by a signal from the control unit (7) described later, and except when measuring the inner diameter of the work (9), the cover (53) is tilted to cover the contact type sensor (5).
Prevent dust of grinding from splashing on the sensor (5).

Coarse grindstone support (27) and finishing grindstone support (28)
Air motors (31) (41) are attached to the rear surface of the motors, and the rotary shafts (32) (42) of each motor penetrate the support bases (27) (28) and the holders (33) (43) at the penetration ends. It is equipped with The rough whetstone (3) is attached to the holder (33) on the side of the rough whetstone support (27) and the finish whetstone support (28).
Finishing grindstones (4) are detachably attached to the side holders (43). Both grindstones (3) and (4) are formed in a columnar shape, and support shafts (30) and (40) are projectingly provided on the shaft center, and the support shafts (30) and (40)
Is held by the holders (33) (43).

The contactor (50) of the contact type sensor (5),
The height of the axis of each of the rough whetstone (3) and the finishing whetstone (4) matches the height of the axis of the chuck (10). The air motors (31) (41) are independently controlled by a signal from a control unit (7) described later, and are operated only when grinding, so that the grindstones (3) (4) are worked (9). Rotate in the direction opposite to the rotation direction of.

On the cover (12), an amplification unit (55)
(In the example, model CUS-3 manufactured by Daishowa Seiki Co., Ltd.
The operation panel (6) of the NC lathe (1) is provided. The amplification unit (55) amplifies the signal from the contact type sensor (5) so that the distortion is reduced, and controls the operation panel (6).
It sends a signal to (7). The operation panel (6) has an automatic operation switch, a manual operation button, a numerical input keyboard, and the like.

A control unit electrically connected to the operation panel (6)
(7) is a storage unit (71) for storing the control data input from the operation panel (6), based on the data in the storage unit (71), and the data and the signal from the contact sensor (5). Based on the calculation result (72) and the calculation result
(2) It comprises a judging section (73) which issues a signal for control.
In the following description, the forward movement of the table (2), the contact type sensor (5) and the grindstone (3) is a direction approaching the work (9) in the Z-axis direction, and the backward movement is the work (9) in the Z-axis direction. ) Is the direction away from.

In the NC lathe (1), the motors (16) and (17) are operated for arbitrary times by operating the manual operation buttons provided on the operation panel (6) to move the table (2) from the origin. It is possible to slide an arbitrary distance in both the Z-axis direction and the X-axis direction (hereinafter, this is referred to as manual operation). This is a function normally used in NC lathes, and is not a function specially added for the present invention.

The movement of the table (2) during grinding is shown in FIG.
As shown in (a), the grindstone (3) is advanced in the Z-axis direction, then in the X-axis direction as shown in (b), and then in the Z-axis direction as shown in (c). As described above, it is retracted in the X-axis direction. The distance D is shorter than the distance B by the grinding amount per time (0.01 mm (diameter display) in the embodiment). By repeating the above-mentioned operation, the grindstone (3) bites into the inner surface of the work (9) by the grinding amount per time when the X moves in the X axis direction, and grinds the inner surface of the work (9) when the C moves in the Z axis direction. .
Further, it is needless to say that the slide amount of the table (2) which slides in response to the signal sent from the control unit (7) is guaranteed to have extremely high accuracy.

The following data is first stored in the storage unit of the control unit (7).
Remember it at (71). Incidentally, among the following numerical values, all numerical values related to the grinding in the inner diameter direction are the diameters. a. Contact sensor (5), coarse whetstone (3) and finishing whetstone (4)
The respective distances in the X-axis direction from the origin position of the table (2) when their respective axis centers coincide with the axis center of the work (9). b. The diameter of the contactor (50) at the tip of the contact type sensor (5) (when measuring the inner diameter of the work (9), the correct value including the diameter of the contactor (50) is stored). c. Offset amount (When the grindstone is first inserted into the work, it is a reference distance for separating the surface of the grindstone from the inner surface of the work. In the embodiment, both the offset amount of the rough grindstone and the offset amount of the finishing grindstone are 0.20 mm (radius (It is 0.10 mm in the display.) This value corresponds to the distance that the table (2) slides once in the X-axis direction during the grinding shown in Fig. 4B) e. Outer Diameters of Coarse Grinding Stone (3) and Finishing Grinding Stone (4) (In the Examples, both the coarse grinding stone and the finishing grinding stone are 7.00 mm) d. Final target value for grinding (final target inner diameter for finishing wheel (8.0 m
m) and grinding depth length (17.00 mm in the example). In the embodiment, when this numerical value is input for the final machining target inner diameter for the finishing grindstone, the arithmetic unit calculates the grinding target inner diameter for the rough grinding stone to be a value 0.04 mm smaller than the final grinding machining target value. F. The angle at which the coarse whetstone (3) and the finishing whetstone (4) move in the direction of the above-mentioned B (in the embodiment, since it is perpendicular to the Z-axis direction of the table, 9
(0 degree)

Next, the usage of the grinding machine and the function of the control unit (7) will be described. Mount the cylindrical work (9) so that there is no run-out on the chuck (10). The table (2) of the origin position is moved in the X-axis direction and the Z-axis direction by manual operation, and the following data is input to the storage unit (71) of the control unit (7) by operating the operation panel. Z-axis direction reference point of contact type sensor (5) (contact type sensor (5) is applied to the end surface of the work (9), and the distance of movement of the table in the Z-axis direction from the origin at this time) Contact type sensor (5) X-axis direction reference point. (The contact type sensor (5) is applied to the inner surface of the work (9), and the movement distance of the table in the X-axis direction from the origin at this time. The work before grinding is fed back to the calculation unit (72).
(9) The inner diameter is calculated and stored in the storage unit (71). In the embodiment, the work inner diameter is 7.80 mm.) Reference point in the Z-axis direction of the rough grindstone (3) (from the point where the tip of the rough grindstone (3) is brought into contact with the end face of the work (9), it is advanced in the Z-axis direction ( (17.0 mm in the example),
The table is brought into contact with the bottom surface of the workpiece, and the table travels in the Z-axis direction from the origin of the table at this time) The contact position of the rough grindstone (3) (The X-axis reference position of the rough grindstone (3) is With the axis
This is the movement position from the origin of the table when the axes of the chucks (10) coincide with each other, and this is stored in the control unit (7) in advance. The contact position of the rough grindstone (3) is the distance from the shaft center of the work to the inner surface of the work, and can be automatically calculated from the inner diameter of the work with e. In the embodiment, since the diameter is displayed, 0.8), the above-mentioned, puts a finger on the rough grindstone (3), and feels that the grindstone (3) is in contact with the end surface or the inner surface of the work to perform the work.

After inputting the above data, the table
Return (2) to the origin position and press the machining start button. The table (2) moves laterally in the X-axis direction, then moves forward in the Z-axis direction, and the coarse grindstone (3) enters the Z-axis direction reference point (17.0 mm depth from the work tip surface). ). At this time, the offset amount, that is, 0.20 mm is separated between the peripheral surface of the rough grindstone (3) and the inner surface of the work (9). Then, a rough whetstone
(3) moves in the order of B → H → D → A in FIG. 4, and repeats this cycle.

The section lengths of a and c are the depth of grinding,
It is 17 mm. The section length of B is the offset amount, 0.2 m
m. The section length of D is determined by the amount of grinding per offset from the offset amount (0.01 mm in the embodiment (0.00 mm in radius display).
5 mm)), that is, 0.19 mm. Therefore,
Coarse whetstone (3) moves in the order of a → b → c → d in FIG.
During the second cycle, at the end of (b), the rough grindstone (3) digs into the inner surface of the work (9) by 0.01 mm (in the radius display, 0.005 mm), and the inner surface of the work (9) is struck in the section of c. Grind 01 mm.

The processing process will be described. Calculation mode Now, the final machining target diameter is 8.00 mm and the grinding depth is 17.0.
mm, angle 90 degrees, offset amount 0.20 mm, contact position of coarse grindstone 0.80 mm, and outer diameter 7.00 mm of grindstone are input as data. 1. Deflection calculation due to overhang The distance (overhang) from the holder (33) (43) to the grindstone (3) (4) corresponds to the depth of the hole to be ground in the product. , If it is 63 mm or more, 0.2 mm, 5
If it is 0 mm or more and less than 63 mm, 0.16 mm;
If it is less than m, it is empirically determined to be 0.1 mm 0, and if it is 35 mm or less, it is 0.08 mm. If the depth of the hole to be ground is input, the calculation unit (72) of the control unit (7) calculates it. Storage (71)
To memorize.

2. Rough machining target calculation A. Target processing diameter for rough whetstone (3) Finish inner diameter of work -0.04 is set as target processing diameter for rough whetstone (3). 0.04 is a finishing grindstone (4) that is post-processing
It is a numerical value obtained empirically in consideration of the grinding allowance. Rough machining target value = 8.00-0.04 = 7.96 B. 1st movement target value of the rough whetstone (3) The 1st movement target value of the rough whetstone (3) is the forward movement of the rough whetstone (3) in the X-axis direction until the first inner diameter measurement. This is a target value, and is not a numerical value of the grinding allowance when the coarse grindstone (3) moves in one cycle as shown in FIG.
The target movement value of the grindstone for the first time is a numerical value obtained by subtracting the outer diameter of the coarse grindstone from the target value of rough machining and further reducing the wobbling amount of the grindstone to prevent excessive grinding. 1st coarse grindstone movement target value = 7.96-7.00-
0.08 = 0.88 C.I. The first point in the X-axis direction when the grindstone approaches the work and starts machining. The first point in the x-axis direction when the rough grindstone (3) approaches and starts machining should be the contact position of the rough grindstone (3). In consideration of the deflection of the rough whetstone (3) (the above-mentioned numerical value of 0.08), 0.02 was reduced in consideration of safety. Point in the X-axis direction where the whetstone starts processing (current position information)
= Contact position of the grindstone-0.02 Current position information of the grindstone = 0.8-0.02 = 0.78

3. Dividing the angle with the bottom of the grindstone Calculate the z-axis coordinate of the end point of b of the movement of a → ro → c → d → in Fig. 4. In the embodiment, since the angle is 90 degrees, it has the same value as the z-axis coordinate of the end point of B. 4. Calculation of the movement coordinate value of a → ro → ha → d → in FIG. 4 End point coordinate of x End point coordinate in X axis direction = coordinate of X axis current position of grindstone−offset amount 0.58 = 0.78−0.2 (0 0.58 is a variable that changes with the progress of grinding.) Z-axis end point coordinate = 0.0 (0.0 is a constant) B end point coordinate X-axis end point coordinate = current position coordinate of the grindstone Therefore, 0.78 (0.78 is a variable that changes with the progress of grinding) Z-axis end point coordinate = a Z-axis coordinate, therefore 0.0 (0.0 is a constant) Ha end point Coordinates X-axis end-point coordinate = b X-axis end-point coordinate, therefore 0.78 (0.78 is a variable that changes with the progress of grinding) Z-axis end-point coordinate = machined hole depth 17.0 (17.0 is a constant) D End point coordinate X axis direction end point coordinate = a X axis direction end point coordinate Therefore, 0.58 (0.58 is grinding A variable which varies with the progress of) Y of axis direction of the end point coordinate = C Y-axis direction of the end point coordinates

In the first cycle of the first grinding, the grindstone is referred to as the "1-1st cycle", and the second and subsequent cycles of the first grinding are the "1-2nd cycle" and the "first cycle". -3), when it comes to the start point of a in FIG. 4, the first movement target value of the coarse grindstone and the current position information (not the current position of the coarse grindstone a,

The present position information described in 1) is compared with the current position information, and the operator (<) makes a determination. 0.78 <0.88, and while the conditional expression of the repeat control statement is satisfied, that is, the determination unit (73) determines that the current position information of the grindstone does not reach the movement target value, and the current position information is determined. A grinding signal is generated by adding 0.01 mm of grinding allowance for one cycle to 0.78. 0.78 + 0.01 = 0.79 The coarse whetstone (3) moves in the order of a->b->c-> d and goes to No. 1-1.
Perform the second polishing. During the movement, at the end of C, that is, the start point of D, the moving target value 0.88 of the first rough grindstone is compared with the current position information 0.79, and the operator (<) is used for the determination. 0.79 <0.88, and while the condition expression of the repetitive control statement is satisfied, that is, the determination unit (73) determines that the current position information of the grindstone does not reach the movement target value, and the determination unit (73) issues a grinding continuation signal, and the rough whetstone (3) shifts to the 1-2nd grinding operation.

The movement target value 0.88 of the first coarse grindstone is compared with the current position information 0.79, and the operator (<) discriminates and the current position information of the coarse grindstone reaches the movement target value. Since it is not available, add 1 cycle of grinding allowance of 0.01 mm to the current position information of 0.79. 0.79 + 0.01 = 0.80 The coarse whetstone (3) moves in the order of a->b->c-> d and performs the first to third grinding. At the end point of C, comparison is made in the same manner as above, and discrimination is made by the operator (<). The numerical value obtained by adding 0.01 to the X-axis direction current value of the grindstone is 0.88.
Comparison calculation and grinding are repeated until the point is closest to the point without exceeding.

In the case of the embodiment, the variable value when the grindstone performs the 1-10th grinding and reaches the end point of C in FIG.
88, which agrees with the first movement target value of the grindstone in the calculation. At the end point of C, comparison is performed in the same manner as above, and discrimination is performed by the operator (<). Since 0.88 <0.88 and the conditional expression of the repeat control statement is not satisfied, the next 1-11th machining is not performed and the measurement mode by the touch sensor is entered.

The table (2) automatically slides to allow the contact type sensor (5) to enter the axial center of the work (9), and subsequently to move the contact type sensor (5) in the X-axis direction. . The moving distance of the contact type sensor (5) from the work axis at the moment when the detection axis (51) of the contact type sensor (5) hits the inner surface of the work (9) is stored in the storage unit (71). Next, contact sensor
(5) is moved to the opposite side, the detection axis (51) is brought into contact with the inner surface on the opposite side of the work (9), and the moving distance of the contact type sensor (5) is automatically stored. The calculation unit has the contact type sensor (5) moving distance in the X-axis direction and the contact type sensor input in advance.
From the diameter of the contactor (50) of (5), the inner diameter of the work (9) is measured. The inner diameter measurement work is repeated once or a plurality of times, and in the case of a plurality of times, the arithmetic unit calculates the average value.

If the measurement result by the touch sensor is 7.
If it is 89, the calculation is as follows. Roughing target value 7.96 is compared with measurement result value 7.89 7.89 <7.96 Find difference between roughing target value and measurement result value 7.96-7.89 = 0.07 The target movement value of the second grindstone is obtained by adding 0.07 to the first target movement value of the grindstone. 0.95 = 0.88 + 0.07 Restart grinding.

In the first cycle of the second grinding (the 2-1st grinding), when the grindstone reaches the starting point of (a) in FIG.
Moving target value for coarse grinding wheel for 0.95 and current position information for 0.88
And are compared, and the operator (<) is used for discrimination. 0.88 <0.95, and while the conditional expression of the repeat control statement is satisfied, that is, the determination unit (73) determines that the current position information of the grindstone does not reach the movement target value, and the current position information is determined. A grinding signal is generated by adding 0.01 mm of grinding allowance for one cycle to 0.88. 0.88 + 0.01 = 0.89 The coarse whetstone (3) moves in the order of a->b->c-> d and goes to 2-1.
Perform the second polishing. During the movement, at the end of c, that is, the start point of d, the second movement target value of the rough grindstone of 0.95 is compared with the current position information of 0.89, and the operator (<) is used to make a determination. While 0.89 <0.95, and the conditional expression of the repeat control statement is satisfied, the judgment unit (73) issues a grinding continuation signal and the grindstone moves in the order of a → b → c → d. The 2nd-2nd grinding is performed. At the end of c, the calculation for grinding in the next cycle is performed. 0.89 + 0.01 = 0.90

The variable value in the X-axis direction when the grindstone reaches the end point of c in FIG. 4 at the 2-7th time becomes 0.95, which coincides with the movement target value of the second grindstone. At the end point of C, comparison is performed in the same manner as above, and discrimination is performed by the operator (<). Since 0.95 <0.95 and the conditional expression of the repetitive control statement is not satisfied, the position of the coarse grindstone (3) in the X-axis direction exceeds the movement target value of the grindstone. Without processing, move to the measurement mode using the touch sensor.

If the inner diameter after the first measurement is 7.89 and the calculation is +0.07, and the measurement result by the touch sensor is 7.96, the calculation is performed as follows. The rough machining target value 7.96 is compared with the measurement result value 7.96, and since they match, the machining with the rough grindstone (3) ends. Even if the rough machining target value and the measurement result value do not match, if the measured value does not exceed the rough machining target value and comes closest to the target value, the program with the rough whetstone (3) is finished Has been done. The last measured value in the grinding process with the rough grindstone (3) is stored in the storage unit (71), and the grinding with the finishing grindstone (4) is based on this measured value The amount of grinding can be set to 0.01. If the final grinding target diameter is calculated, the contact type sensor (5)
To measure the inner diameter.

If the measured value does not reach the final grinding target inner diameter, comparison calculation and grinding are repeated in the same manner as in the grinding step with the rough grindstone (3). Grind until the final grinding target inner diameter is reached. However, when grinding with the finishing whetstone (4), the X-axis direction current value of the whetstone is more than the movement target value of the whetstone,
In case of 0.01 or less, that is, the final grinding amount is 0.0 in calculation.
If it is less than 1 mm, calculate the difference in the X-axis direction current value of the whetstone from the movement target value of the finishing whetstone (4), and add the difference to the whetstone current value, that is, the X-axis by the difference. The controller (7) is programmed to move in the direction.
After finishing the inner surface grinding of one work (9), a new work (9) is replaced with the chuck (10),
Data is input to grind the work (9).

As described above, the automatic grinding apparatus of the present invention automatically measures the measurement conventionally performed manually by the operator by using the movement of the table of the NC lathe, and based on this measured value, the machining is performed. Since grinding is automatically advanced until the target value is reached, it does not require the intuition and skill of the operator as in the past, and it has made possible the labor saving of highly accurate grinding. Also, table (2)
Slides in only two axes, the Z-axis direction and the X-axis direction,
It suffices to dispose the grindstone (3) and the contact type sensor (5) on the table (2) of the relatively inexpensive NC lathe, and the equipment cost can be kept low.

In the apparatus of the present invention, when the diameter of the grindstones (3) and (4) is larger than the inner diameter of the work before grinding, the contact type sensor (5) or the grindstones (3) and (4) are used for the work. At the time of insertion into (9), if data is input so that they collide with the work, safety is taken into consideration so that the movement of table (2) is stopped and an alarm is issued. In the practice of the invention,
The first grinding, that is, the first by the contact type sensor (5)
Up to the measurement of the first time, grinding may be performed by repeating the number of cycles necessary for calculation without performing the comparison calculation for each cycle of the rough grindstone (3). In the practice of the present invention, a rough whetstone
(3) Alternatively, it is possible to omit the finishing grindstone (4) and perform grinding with only one of the grindstones. Further, it can be used not only for the inner surface of the cylindrical body but also for the outer surface grinding. in this case,
As shown in FIG. 6, the outer surface of the contact type sensor (5) is measured by the contact type sensor (5) as a → b → c → d → e → f → g.
Slide the table (2) so that the contact type sensor (5) moves when moving in the b and g directions.
(9) From the deviation of the position in the X-axis direction when hitting, work
The outer diameter of (9) can be calculated.

FIG. 7 shows the movement of the grindstone (3) when the inner bottom of the work (9) is a tapered surface (91). Grindstone
Since (3) can be slid simultaneously in two directions, the Z-axis direction and the X-axis direction, such processing is possible. Tapered surface
When grinding (91), the grindstone (3) is not moved in the taper direction, but the grindstone is simply pressed against the taper surface, whereby grooves with a minute width appear minutely in the circumferential direction on the taper surface. However, if grinding is performed while moving the grindstone (3) in the taper direction, the above groove is not formed and the surface is finished to be a mirror surface. As shown by the chain double-dashed line, the grindstone (3) may be tapered, and the opening angle α ₁ of the tapered surface may be larger than the opening angle α ₂ of the tapered surface of the work (9). In the example, the work
By inputting the opening angle α ₂ of the finishing taper surface of (9) and the depth of the taper surface, the movement of the grindstone is automatically controlled by the calculation of the calculation unit (72).

In the apparatus of the present invention, as shown in FIG.
It is also possible to process the inner surface of a workpiece with continuous holes of different diameters.
In carrying out the present invention, the chuck (10) and the rough grindstone
(3), the finishing grindstone (4) and the contact type sensor (5) may be arranged vertically to configure the apparatus. The present invention is not limited to the configuration of the above embodiment, and various modifications are possible within the scope of the claims.

[Brief description of drawings]

FIG. 1 is an overall perspective view of a grinding device.

FIG. 2 is a perspective view of an essential part of the above.

FIG. 3 is an explanatory view of a state in which a grindstone is inserted into a work.

FIG. 4 is an explanatory diagram of a moving order of a grindstone in a work.

FIG. 5 is a flowchart of a grinding procedure.

FIG. 6 is an explanatory diagram for measuring an outer diameter of a work.

FIG. 7 is an explanatory diagram of a grinding procedure for a tapered work.

FIG. 8 is a cross-sectional view of a work in which different diameter holes are continuous.

[Explanation of symbols]

 (1) NC lathe (2) Table (3) Coarse grindstone (4) Finishing grindstone (5) Contact sensor (6) Control panel (7) Control section (9) Workpiece

Claims (1)

[Claims] 1. A rotary chuck (10) for gripping and rotating a workpiece (9), a Z-axis direction along the axis of the chuck (10), and the Z-axis.
A grinding tool supporting table (2) slidable in two X-axis directions orthogonal to the axial direction, motors (16) (17) for driving the table (2) in the Z-axis direction and the X-axis direction, and a workpiece. An operation panel (6) for inputting machining data for (9), and a control unit (which controls the motors (16), (17) by calculation based on an input signal from the operation panel (6) and a signal from the outside ( NC with 7)
On the lathe (1) and the grinding tool support base (27) on the table (2) of the NC lathe (1), the holder (33) connected to the motor (31) is detachably supported, and the work support is supported. Grinding tool (3) arranged at the same height as the axis of the rotary chuck (10) and parallel to the axis of the chuck (10), and a grinding tool on the table (2) of the NC lathe. It is arranged adjacent to the support base (27), and the detection shaft (51) is at the same height as the axis of the rotary chuck (10) and parallel to the axis of the chuck (10), and the contact signal is And a contact type sensor (5) for inputting to the control section (7) of the NC lathe, the control section (7) is a storage section (71) for storing processing data,
An arithmetic unit (72) for performing an operation for controlling the table (2) based on the processed data, and the table (2) based on the operation result.
Equipped with a determination unit (73) that outputs a signal for control, if the grinding progresses to a calculated set diameter that takes into account factors such as wobbling of the grindstone that cause too much grinding than the calculated value, grinding is automatically performed. Suspended and contact sensor by movement of table (2)
(5) is moved to measure the diameter of the work (9), the difference between the machining target value and the measured value is stored in the storage unit (71), and after the grinding is restarted,
The calculation unit (72) compares the difference between the processing target value and the measured value each time grinding is performed and the grinding amount per grinding × grinding count,
Grinding is repeated according to a command from the judgment unit (73) until the calculated grinding amount reaches the processing target value, and when the grinding amount reaches the processing target value on the calculation, the grinding is stopped and the contact type is repeated again as described above. The diameter of the work (9) is measured by the sensor (5), and if the measured value does not reach the processing target, the difference between the processing target value and the measured value is stored in the storage unit (71) again, and the same as above. An automatic grinding machine characterized by continuing to grind and measure.