JP3497976B2 - Numerically controlled grinding machine - Google Patents

Description

Detailed Description of the Invention

[0001]

[Industrial field of application] A traverse motion in which a grindstone reciprocates along a workpiece machining surface shape relative to a workpiece, a cutting action that advances and retracts in the workpiece radial direction, and a direction change at both ends of the traverse action. The present invention relates to a numerically controlled grinder (hereinafter referred to as NC grinder) capable of instructing a traverse starry operation for stopping the traverse operation and the cutting operation at least for a time during which the workpiece rotates once.

[0002]

2. Description of the Related Art When a working width of a workpiece is wider than a grindstone contact surface contacting the workpiece, a traverse operation for reciprocating left and right between both ends of the working surface and a radial direction of the workpiece as shown in FIG. The traverse grinding function is used to perform a cutting operation that moves forward and backward. As the operation pattern of the traverse grinding function, a traverse continuous cutting operation pattern (see FIG. 4A) that simultaneously performs the traverse operation and the cutting operation, and a traverse intermittent cutting that alternately performs the traverse operation and the cutting operation. There is an operation pattern (see FIG. 4B). In FIG. 4, the traverse motion is a lateral motion, and the cutting motion is performed in the upward direction. In the traverse operation, the traverse operation speed moves a distance smaller than the width of the grindstone processing surface with respect to one rotation time of the workpiece in order to perform cutting over the entire circumference of the processed portion of the workpiece. In addition to the speed, at both ends of the traverse operation, the traverse operation and the cutting operation are stopped for one rotation time of the workpiece or more. Generally, the operation of stopping the traverse operation and the cutting operation is a traverse star operation,
The stop time is referred to as the traverse time.

Now, a conventional technique using the traverse grinding function will be described with reference to FIGS. 3 and 5. FIG. 3 shows an example of performing traverse grinding on the inner diameter of the workpiece. FIG. 5 shows a configuration example of an NC grinder that performs the traverse grinding process. CM for traverse grinding
Consists of the traverse command type, traverse end position, cutting completion position, traverse star time, etc. An example of the traverse grinding command CM will be shown below. G25 XE = 12.25 ZE = 50 F6 FT = 600 TT = 2 G26 XE = 12.25 ZE = 50 E0.5 FC = 6 FT = 600 TT = 2 G25: Traverse continuous cut (operation pattern) G26: Traverse intermittent Depth (operation pattern) XE: Depth completion position ZE: Traverse end position E: Intermittent depth of cut FC: Depth of cut FT: Traverse speed TT: Traverse star re-time The position before execution of the traverse grinding command CM is X = 10, When Z = 100, traverse continuous cutting command (G25), traverse intermittent cutting command (G26)
Both traverse right end Z = 100, traverse left end Z = 5
The both ends of 0 are traversed at the traverse speed FT = 600, and the cutting operation is further performed at the cutting speed FC = 6 until X = 10 to X = 12.25. X = 12.2
The cutting operation is completed when it reaches 5, and the traverse operation is completed when the traverse right end Z = 100, which is the position before the execution of the traverse grinding command CM, is returned.

The command analysis unit 2 analyzes the traverse grinding command CM, and a motion pattern PT indicating a combination of the three motions of the traverse motion, the cutting motion and the traverse starry motion, the cutting completion position XE, and the traverse end positions. The axis parameter PR such as the position ZE and the traverse star time TT are divided. In the example of the traverse grinding command CM, G25 and G26 are the operation patterns PT. The motion pattern PT obtained here is stored in the motion pattern storage unit 3 along with the axis parameter PR and the traverse star time T.
T is sent to the axis parameter storage unit 6. In addition, in order to determine the first traverse movement direction, the axis parameter P
R is also sent to the moving direction determination unit 4.

The operation pattern storage unit 3 stores the operation pattern PT sent from the command analysis unit 2 and sends it to the function generation unit 8. The movement direction determination unit 4 obtains the first traverse movement direction DS from the axis parameter PR sent from the command analysis unit 2, and further, the function generation completion signal FN for the traverse 1 direction movement sent from the function generation unit 8 is sent. Each time it is sent, the traverse movement direction DS is inverted and sent to the axis movement data calculation unit 7. The first traverse movement direction DS is the direction in which the traverse grinding command CM is moved from the position before execution of the traverse grinding command CM to the traverse end position ZE commanded by the traverse grinding command CM.

The axis parameter storage unit 6 stores the axis parameter PR and the traverse starry time TT sent from the command analysis unit 2, and sends them to the axis movement data calculation unit 7.
The axis movement data calculation unit 7 uses the axis parameter PR sent from the axis parameter storage unit 6 and the traverse starry time TT and the traverse movement direction DS sent from the movement direction determination unit 4 to move the traverse in one direction. Axis movement data AD such as the target value, the axis movement speed, and the traverse star time are calculated and sent to the function generator 8.

The function generator 8 generates a function for a cutting operation and a traverse operation based on the operation pattern PT sent from the operation pattern storage 3 and the axis movement data AD sent from the axis movement data calculator 7. Then, the data is sent to two shaft driving units (not shown). Further, when the function generation for the movement in one direction of traverse is completed, the function generation completion signal FN is sent to the movement direction determination unit 4. The operations of the movement direction determination unit 4, the axis movement data calculation unit 7, and the function generation unit 8 are repeated until the cutting operation and the traverse operation are completed. When the cutting operation is completed in the middle of the traverse operation, the function generation of the cutting operation is completed at that time, but the function generation of the traverse operation is performed until it returns to the traverse end before the execution of the traverse grinding command CM.

[0008]

In the case of machining the inner diameter of the work piece shown in FIG. 3, the traverse right end position is usually set such that the right end of the grindstone work surface is rightwardly protruded from the right end of the work piece work surface. This is because the grindstone is hard but brittle,
This is because the corners at both ends of the grindstone processing surface are likely to be chipped, and only the chipped parts are not processed. On the other hand, the left end of the traverse is located slightly to the right of the left end surface of the work so that it does not hit the left end surface of the work. In the conventional traverse grinding function, it is premised that the traverse star time is obtained from the rotation time of the workpiece, and the traverse right end and the traverse left end are controlled to be the same time. Therefore, when the workpiece and the grindstone have different contact widths at both ends of the traverse as in the above-described example, the smaller contact width results in excessive cutting. This is because the forces acting between the workpiece and the grindstone (in the example of FIG. 3, the rigidity and the amount of deflection of the inner grinding wheel spindle quill) are the same and the contact widths are different,
This is because the force applied per unit area of the grinding surface of the grindstone increases as the contact width decreases. In addition, when the rigidity of the processed portion of the work at both ends of the traverse is different, such as when performing traverse grinding on the workpiece that supports one side, the one with weaker rigidity (the right end of the traverse in the example of FIG. 3) has a larger amount of deflection of the workpiece. , Left uncut remains.

In the above case, since it is necessary to correct the depth of cut by adjusting the traverse star time, the conventional traverse grinding function cannot be used, and the traverse operation to the right end of the traverse Movement, traverse star right movement at traverse,
The traverse operation to the left end of the traverse, the cutting operation, and the traverse starry operation at the left end of the traverse must be programmed in the order of operation, which is very troublesome.

The present invention has been made under the circumstances as described above, and an object of the present invention is to perform a traverse grinding process when the contact width between the work surface and the grindstone grinding surface at both ends of the traverse differs. An object of the present invention is to provide an NC grinder having a traverse grinding function capable of making the finished dimensions of both ends of the traverse the same even when the rigidity of the processed portion is different.

[0011]

The present invention is directed to a traverse operation in which a grindstone moves reciprocally along a work surface shape of a work piece, a cutting operation for moving the work piece in a radial direction of the work piece, The present invention relates to a numerical control grinder capable of instructing a traverse star re-operation that stops the traverse operation and the cutting operation for at least one rotation time of the workpiece at the time of changing the direction of the traverse operation. At both ends of the traverse motion
Commanding means for commanding conditions in the traverse starry operation based on a contact width between the workpiece and the grindstone in the traverse starry operation
Time to stop means for determining separately for both ends of the traverse operation time to stop the traverse operation and cut operation from the condition, the traverse operation and cut operation determined separately for both ends of the traverse operation It is achieved by having means for performing the traverse star action based on As a result, it is possible to prevent variations in the finished dimensions due to the difference in the contact width.

[0012] The numerical control grinding machine of the other of the present invention, the door
At the processing parts of the workpiece at both ends of the lathe movement.
Based on the kicking workpiece stiffness, and command means for commanding the conditions in the traverse Tari operation, before it said commanded
Means for separately determining the time to stop the traverse operation and the cutting operation from the conditions in the traverse starry operation for both ends of the traverse operation, and the traverse operation and the cutting operation separately obtained for both ends of the traverse operation It has means for performing the traverse star operation based on the time when the operation is stopped. As a result, it is possible to prevent variations in the finished dimension due to the difference in rigidity between the both ends of the traverse operation in the processed state.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing an example of an NC grinder according to the present invention in correspondence with FIG. 5, and the same components will be assigned the same reference numerals and explanations thereof will be omitted. The traverse grinding command CM is added with traverse star correction times CL and CR for each traverse end for command. An example of the traverse grinding command CM will be shown below. G25 XE = 12.25 ZE = 50 F6 FT = 600 TT = 2 CL = 0 CR = 0.2 G26 XE = 12.25 ZE = 50 E0.5 FC = 6 CL = 0 CR = 0.2 FT = 600 TT = 2 CL: Traverse star correction time at the left end of traverse CR: Traverse star correction time at the right end of traverse command analysis unit 2 analyzes traverse grinding command CM, and traverse star correction time CL at each traverse end,
The CR is sent to the tally time calculation unit 5 together with the axis parameter PR and the traverse star time TT. The Thali time calculation unit 5 calculates the corrected traverse star time TL, TR from the traverse star correction time CL, CR and the traverse star time TT read from the command analysis unit 2,
It is sent to the axis parameter storage unit 6 together with the axis parameter PR.

An example of the operation of the tally time calculating section 5 which is the main part of the present invention in such a configuration will be described with reference to the flowchart of FIG. First, the left end tally correction time C, which is the correction time for the traverse stary time at the left end of the traverse
It is determined whether or not L is sent from the command analysis unit 2 (step S1), and if it is sent, the left end thali correction time CL is subtracted from the thali time TT to obtain the left end thali time T.
L is calculated (step S2). If it has not been transmitted in the determination of step S1, the tally time TT is set to the left end tally time TL (step S3). It is determined whether or not the right end tally correction time CR, which is the correction time for the traverse stary time at the right end of the traverse, is sent from the command analysis unit 2 (step S4), and if so, the right end tarry correction time CR is calculated from the tarry time TT. The subtraction is performed to calculate the right end tally time TR (step S5). Step S
In the determination of 4, if not transmitted, the tarry time TT is set to the right end tally time TR (step S6).

The above embodiment shows an example in which the traverse starry time is corrected by separately instructing the traverse starry time at the right end of the traverse and the traverse starry time at both ends from the commanded correction time. However, instead of instructing the correction time, the correction coefficient, that is, the correction ratio to the traverse star time may be separately instructed at the traverse right end and the traverse left end to obtain the traverse star time. Further, the same effect can be obtained by directly instructing the traverse starry times at the right end of the traverse and the left end of the traverse instead of obtaining the traverse starry time using the correction time / correction coefficient. Further, in the case of the variation in the finished size caused by the difference in the contact width between the grindstone and the workpiece at the both ends of the traverse as in the grinding process of FIG. 3, the traverse star time or the traverse star recovery is calculated from the ratio of the contact width at the both ends of the traverse. It is also effective to obtain the correction time. Further, the traverse star re-correction time or the traverse star re-correction time may be obtained according to the rigidity of the workpiece in the processed portion of the workpiece at both ends of the traverse operation. For example, in the case of variations in the finished dimensions that occur due to differences in the workpiece rigidity at the processing parts at both ends of the traverse, such as the traverse operation of a workpiece that supports one side in cylindrical grinding, command the rigidity at both ends of the traverse and calculate the ratio of the rigidity. The traverse starry time or the traverse starry correction time may be obtained. Further, since the rigidity in the case of attaching a steady rest or the like to the work supporting the one side and performing the machining is different, it is effective to obtain the traverse star retime or the traverse star recorrection time in consideration of these machining states. .

[0016]

As described above, according to the NC grinder of the present invention, even when the contact widths of the grindstones at both ends of the traverse operation are different or the rigidity of the work piece machining portion at both ends of the traverse operation is different, the finished dimension is obtained. It is possible to instruct the traverse grinding process without causing the variation of No. and without creating a troublesome program.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a controller of an NC grinder having a tarry time correction function of the present invention.

FIG. 2 is a flowchart illustrating an operation example of a main part of the device of the present invention.

FIG. 3 is an explanatory diagram showing a processing operation of a general NC grinder.

FIG. 4 is an explanatory diagram showing two types of operation patterns of a traverse grinding function.

FIG. 5 is a block diagram showing an example of a control device for an NC grinding machine according to a conventional device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 operation panel, 2 command analysis section, 3 motion pattern storage section, 4 moving direction determination section, 5 tari time calculation section, 6
Axis parameter storage unit, 7 axis movement data calculation unit, 8 function generation unit.

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B24B 1/00 B24B 5/06

Claims (2)

(57) [Claims] 1. A traverse operation in which a grindstone moves reciprocally along a work surface shape of a workpiece relative to a work piece, a cutting operation for advancing and retreating in the workpiece radial direction, and at least the traverse operation when the traverse operation changes direction. In a numerically controlled grinding machine capable of instructing a traverse star re-operation for stopping the traverse operation and the cutting operation only for the time of one revolution of the workpiece, the workpiece and the grind at both ends of the traverse operation.
Command means for instructing conditions in the traverse starry operation based on the contact width of stones, and the commanded conditions in the traverse starry operation
From the means for separately determining the time for stopping the traverse operation and the cutting operation for both ends of the traverse operation, and for the time for stopping the traverse operation and the cutting operation separately obtained for both ends of the traverse operation And a means for performing the traverse starry operation based on the numerically controlled grinding machine. 2. A traverse operation in which a grindstone moves reciprocally along a workpiece machining surface shape relative to a workpiece, a cutting operation that advances and retracts in the workpiece radial direction, and at least when the traverse operation changes direction. In a numerical control grinder capable of instructing a traverse star re-operation for stopping the traverse operation and the cutting operation only for the time when the work rotates once , a processing part of the work at both ends of the traverse operation.
Command means for instructing a condition in the traverse starry operation based on the rigidity of the workpiece at the position, and the commanded condition in the traverse starry operation.
From the means for separately determining the time for stopping the traverse operation and the cutting operation for both ends of the traverse operation, and for the time for stopping the traverse operation and the cutting operation separately obtained for both ends of the traverse operation And a means for performing the traverse starry operation based on the numerically controlled grinding machine.