JPH0523908B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention provides a grinding machine in which the angle of the grinding wheel head is variable, so that the relative movement locus of the grinding wheel with respect to the workpiece is tilted at a desired angle with respect to the spindle axis.
The present invention relates to a feed control device that performs axis control.

[Prior art]

When simultaneously grinding the cylindrical part of the workpiece and the end face of the shoulder adjacent to it, conventionally the feeding means of the grinding wheel head is angularly moved so that the travel path of the grinding wheel head is obliquely intersecting the spindle axis at a certain angle. It has a sliding structure. In this case, when processing the shoulder end face of a workpiece by relatively moving the grinding wheel in a direction orthogonal to the main axis, it is necessary to simultaneously perform pulse distribution on two axes to move the grinding wheel. For this reason, when grinding the shoulder end face, meandering of the grinding wheel occurs due to non-uniform pulse distribution, and there is a problem in that the shoulder end face cannot be ground with high precision. To solve this problem, an angular-shaped grinding wheel is movably guided in a direction perpendicular to the spindle axis, so that the shoulder end face can be machined in one axis direction of the grinding wheel, and the cylindrical part and the shoulder end face are When grinding is performed at the same time, the grinding wheel may be moved in a relatively diagonal direction to perform the grinding. To control such feed, two axes may be controlled simultaneously as follows. If the angle between the sliding direction of the grinding wheel and the grinding direction is θ, and the feed amount in the direction perpendicular to the main axis of the grinding wheel is r, input r into the numerical control device as the amount of movement of the grinding wheel, and It is sufficient to calculate and input the table movement amount ΔZ as r tan θ, and program the pulse distribution command code so that pulse distribution is performed on two axes simultaneously.

[Problems to be solved by the invention]

However, in this method, it is necessary to individually calculate and input the command movement amount of the workpiece table, which not only makes it extremely troublesome to input numerical control data, but also because the workpiece table calculated by r tan θ Since the amount of movement has a fraction, there is a problem in that mistakes in setting the amount of movement are likely to occur. Furthermore, when the angle of the grindstone head is changed according to the grindstone angle, the grinding angle θ is also changed. Therefore, each time a grindstone with a different grindstone angle was installed, the amount of movement of the workpiece table had to be recalculated, which required a large amount of time to create the NC data. The present invention is intended to solve such problems, and its purpose is to variably set the grinding angle θ and automatically adjust the table movement based on the grinding wheel movement r and the set grinding angle. The aim is to facilitate the setting of NC data by calculating and controlling two axes simultaneously.

[Means to solve the problem]

The structure of the invention for solving the above problems is as follows, and the concept thereof is shown in FIG. It is arranged so that it can rotate freely relative to the bed, and
A grindstone head 17 that is movable relative to the workpiece W in a first axis X direction perpendicular to Os and a second axis Z direction parallel to the spindle axis is provided with a first grinding surface Ga parallel to the spindle axis; An angular-shaped grinding wheel G having orthogonal second grinding surfaces Gb is mounted on a shaft, and the first,
In a feed control device for a numerically controlled grinding machine, the grinding wheel is moved relative to the first axis along an oblique path A by simultaneous two-axis movement in the second axis direction, A grinding angle θ indicating the direction of grinding of the grinding wheel along the diagonal path passing through the set reference point,
a grinding angle setting means 6 inputting and setting into the data storage means 1 storing numerical control data; and a movement command reading out movement command data in the first axis direction regarding the first grinding surface of the grinding wheel from the data storage means 1. reading means 2; and a first axis that calculates coordinates of an end point position in the first axis direction by adding or subtracting the incremental movement amount to the current position of the grinding wheel in the first axis direction when the movement command data is an incremental movement amount. an end point calculation means 31; and the end point coordinate value calculated by the first axis end point calculation means 31, the coordinates of the reference point, and the grinding angle θ stored in the data storage means 1. Second axis end point calculation means 32 that calculates the coordinates of the end point position existing on the intersection route in the second axis direction
and a subtraction means 33 for calculating the deviation between the end point coordinates calculated by the second axis end point calculation means 32 and the current position of the second axis as the amount of movement in the second axis direction.
and distributing the number of pulses corresponding to the movement command read by the movement command reading means 2 to the first axis, and at the same time, according to the amount of movement in the second axis direction calculated by the subtraction means 33. and pulse distribution means 4 for distributing a number of pulses to the second axis.

[Effect]

The grinding angle setting means 6 inputs and sets in the data storage means 1 a grinding angle indicating the grinding direction of the grinding wheel based on the angle formed between the grinding surface of the grinding wheel and the grinding wheel shaft, the rotation angle of the grinding wheel head, and the like. The movement command reading means 2 reads the incremental command movement amount r of the grindstone head 17 in the first axis X direction from the NC data stored in the data storage device 1 and outputs it to the first axis end point calculation means 31. 1st
The axis end point calculating means 31 calculates the coordinates X _E of the end point position in the first axis direction by adding or subtracting the incremental movement amount r from the current position X _N of the grinding wheel in the first axis direction. The second axis end point calculation means 32 calculates the end point coordinate value X _E calculated by the first axis end point calculation means 31.
and the coordinates of the reference point (X _S , Z _S ) and data storage means 1
Based on the grinding angle _θ stored in
Calculate. Then, the subtraction means 33 calculates the deviation ΔZ between the end point coordinate Z _E calculated by the second axis end point calculation means 32 and the current position Z _N of the second axis as the amount of movement in the second axis direction. . The pulse distribution means 4 calculates, from the movement amount r in the first axis direction and the determined movement amount ΔZ in the second axis direction,
At the same time, pulses are distributed to two axes. As a result, the grinding machine is driven, and the relative movement direction of the grinding tip of the grinding wheel is controlled to be in the selected grinding direction θ, so that the positioning point always passes through the reference point and makes an angle θ with the first axis. It is controlled to exist on a predetermined diagonal path that intersects at .

【Example】

Embodiments of the present invention will be described below based on the drawings. In FIG. 2, reference numeral 10 indicates a bed of a numerically controlled grinding machine, and a workpiece table 13 on which a headstock 11 and a tailstock 12 are placed is placed on the bed 10. A workpiece W is supported between the headstock 11 and the tailstock 12, and is rotationally driven by the rotation of a main shaft 15 connected to a main shaft drive motor (not shown). And the workpiece table 13
is a servo motor 14 via a screw feed mechanism (not shown).
The shaft is connected to the main shaft axis Os and is moved in the Z-axis direction parallel to the main axis Os. Further, an end face sizing device 16 for positioning the workpiece W in the axial direction is installed on the bed 10 so as to be movable forward and backward. On the other hand, behind the bed 10, a grindstone stand 17 is provided.
is mounted so as to be movable in the X-axis direction perpendicular to the spindle axis Os, and the feed of this grindstone head 17 is controlled via an unillustrated feed screw connected to a servo motor 18. The grindstone head 17 can be rotated about the shaft 24 as a central axis. On the grindstone head 17, an angular-shaped grinding wheel G having a first grinding surface Ga parallel to the spindle axis Os and a second grinding surface Gb perpendicular to the first grinding surface Ga is mounted on the grindstone shaft 17. The bearing is mounted on the shaft. The grinding wheel shaft 19 is obliquely crossed with respect to the main shaft axis Os due to the rotation of the grinding wheel head 17, and as a result, the grinding tip Gp of the grinding wheel G is
It is located in a plane obliquely intersecting the axis of the X-axis at an angle θ. This angle θ indicates the relative moving direction of the grinding wheel G, and is the grinding angle of the grinding wheel. FIG. 3 shows a control circuit for controlling the grinding machine configured as described above, in which 40 indicates the servo motor 1.
Drive circuits 41 and 42 that drive circuits 4 and 18, respectively.
This is a numerical control device that controls machining of a workpiece W by distributing pulses to the workpiece W. This numerical control device 40 includes an arithmetic processing device 45, a memory M, and an arithmetic processing device 4.
5 and a pulse generation circuit 47. A data writing device 48 and the sizing device 16 are connected to the interface 46 . The pulse generation circuit 4
7 includes a pair of pulse generators 47X and 47 that independently distribute pulses to the X-axis and Z-axis, respectively.
Z is provided to simultaneously distribute a commanded number of pulses at a commanded speed. The memory M also has a numerical control data area.
NCDA is formed and this numerical control data area
A machining program shown in FIG. 8 is written into the NCDA using a data writing device 48. Furthermore, an angle data area ADA is formed in the memory M to store the grinding angle θ. In this area, the grinding angle θ is input and set from the data writing device 48 according to the flowchart shown in FIG. When a predetermined key operation is performed, the program shown in FIG. 5 is activated. A display is displayed on the display panel instructing the user to enter the address of the angle data area where the grinding angle is to be stored, and then the user operates a key to enter the address. Then, a display will appear on the display panel instructing you to input the grinding angle, and if you input the grinding angle by operating the keys, the grinding angle will be set in the area ADA. When the processing start command GCS is given to the numerical control device 40, the arithmetic processing device 45 executes the processing shown in FIG. This allows the numerical control data area
The machining programs shown in FIG. 8 stored in the NCDA are sequentially read out and executed. Block N001 is programmed with G09 in addition to G90, which indicates that it is an absolute command. Therefore, the absolute flag ABF is set through steps 57 and 61, and step 56
and 60, the angular feed flag AFF is set. Thereafter, the pulse distribution process shown in FIG. 7 is performed. This allows the programmed
The movement amount ΔZ of the workpiece table 13 is calculated based on the end point coordinate values of the axes, and pulse distribution for the two axes is performed simultaneously. That is, when the flag ABF indicating that the movement command is absolute is set, after setting the X-time movement amount data r as the end point target value X _E in the end point register (not shown) (79), the grinding angle is set. θ is read from the area ADA, and the end point coordinate Z _E of the Z axis is calculated using the following equation (2) (81). Z _E = Zs - (Xs - X _E ) tan θ... (2) Note that the coordinate system is set to be fixed at W on the workpiece. Furthermore, (X _s , Z _s ) are the coordinates of a reference point through which a predetermined oblique route passes in the coordinate system.
In particular, in this embodiment, the coordinates of the reference point are
7 is set to the coordinates seen from the set coordinate system of the grinding tip point Gp of the grinding wheel G when it is positioned at the machine origin. In addition, in the above equation, the term (Xs−X _E ) represents the amount of movement of the first grinding surface Ga from the reference point at the end point position, as shown in Fig. 4, and by multiplying this by tanθ, the end point can be calculated. The amount of movement of the second grinding surface Gb at the position from the reference point can be calculated. Then, by subtracting this calculated value from the second axis coordinate Zs of the reference point, the Z-axis end point coordinate Z _E in the set coordinate system of the second grinding surface Gb at the end point position can be calculated. The origin of the set coordinate system should be set to the spindle axis.
When set to the intersection point Pw of Os and the oblique plane,
Z _E is the distance from this intersection Pw to the end point position in the spindle axis direction. After this, the current values of the X and Z axes X _N , Z _N
The deviations ΔX and ΔZ between the end point coordinates X _E and Z _E are calculated (82), and a number of pulses corresponding to the calculated deviations ΔX and ΔZ are simultaneously distributed to the X and Z axes (83).
This simultaneous two-axis pulse distribution for the X-axis and Z-axis is achieved by setting the travel amounts ΔX and ΔZ for the pair of pulse generators 47X and 47Z in the pulse generation circuit 47, and simultaneously distributing pulses for both axes. This is done by respectively setting the speed data to be completed and simultaneously commanding the start of pulse distribution. As a result, the grinding wheel G moves along the oblique path A in the oblique plane passing through the grinding tip Gp, and the first
The grinding surface Ga is positioned at a position spaced apart by r _ab from the spindle axis Os. On the other hand, the movement command is incremental and flagged.
If the ABF has been reset, the end point coordinates X _E of the X axis are calculated by subtracting the movement amount data r from the current position X _N of the X axis (80), and then Then, the end point coordinate Z _E of the Z axis is calculated (81). Then, as in the previous case, the current position of the X-axis and Z-axis
The deviations ΔX and ΔZ between X _N , Z _N and the end point coordinates X _E , Z _E are calculated (82), and pulses are distributed to both axes simultaneously (83). As a result, the grinding wheel G moves along the oblique path A, and the first grinding surface Ga is advanced by the amount of movement r _re . In this way, even when distributing pulses in the Z-axis direction based on incremental commands, the end point coordinates of the X-axis can be calculated by subtracting the movement amount r from the current X _- axis position
X _E is calculated, and the difference between this end point coordinate X _E and the first axis coordinate X _s of the reference point is multiplied by tanθ to calculate the end point coordinate Z _E of the Z axis.
Since the Z-axis pulse distribution number is calculated by calculating the Z-axis pulse distribution, the positioning error caused by multiplying by tanθ will be This allows for highly accurate feeding. By repeating such a feeding operation, the first grinding surface Ga engages with the cylindrical portion Wa and grinds the cylindrical portion Wa to the finished surface, and the second grinding surface Gb brings the shoulder end surface Wb to the finished surface. The cylindrical portion Wa and the shoulder end surface Wb are simultaneously ground. As described above, even if grinding wheels with different grinding wheel angles are attached to the grinding wheel head and the grinding wheel head is rotated, the grinding angle θ is input and set and the amount of movement of the workpiece table is calculated accordingly. Even complex grinding
There is no need to create an NC program. The grinding angle θ also corresponds to the rotation angle of the grindstone head 17. Therefore, the above-mentioned grinding angle setting means may be configured to automatically detect the rotation angle of the grindstone head 17 using the angle sensor 43 and set this value in the predetermined area ADA.

【Effect of the invention】

As described above, the present invention is provided with a grinding angle setting means for inputting and setting the grinding angle of the grinding wheel, and adds or subtracts an incremental movement amount to the current position in the first axis direction to position the end point in the first axis direction. The coordinates of the end point located on the oblique path in the second axis direction are calculated based on the first axis end point coordinate value, the coordinate of the reference point, and the grinding angle θ. The deviation between the axis end point coordinates and the current position of the second axis is calculated as the amount of movement in the second axis direction. Pulses are distributed simultaneously to the two axes according to these movement amounts, thereby accurately controlling the direction of relative movement of the grinding tip of the grinding wheel to the set grinding angle. Therefore, since the positioning point is always controlled to be on a predetermined oblique path that passes through the reference point and intersects the first axis at an angle θ, the grinding tip point is accurately set without accumulating positioning errors. The vehicle will move on a diagonal route set in advance. Therefore, machining accuracy is improved. Further, since it is only necessary to program the commanded movement amount in the first axis direction, the creation of the NC program becomes easy. Furthermore, even if the grinding direction changes by attaching grinding wheels with different grinding wheel angles to the grinding wheel head, the grinding angle θ
The amount of movement of the workpiece table can be calculated accordingly, so there is no need to create a complex NC program for grinding in any direction.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram for clearly demonstrating the present invention.
2 to 8 show embodiments of the present invention,
Figure 2 is a schematic plan view of a feed control device in a numerically controlled grinder, Figure 3 is a block diagram of a control circuit that controls the grinder shown in Figure 2, and Figure 4 is the amount of movement of grinding wheel G in the X-axis direction. A diagram showing the relationship between and Z-axis movement amount,
5, 6, and 7 are flowcharts showing the operation of the arithmetic processing unit 45 in FIG. 3, and FIG. 8 is a diagram showing a numerical control program. 13... Workpiece table, 17... Grindstone stand, 1
4, 18... Servo motor, 40... Numerical control device, 41, 42... Drive circuit, 45... Arithmetic processing unit, A... Diagonal path, G... Grinding wheel, Ga...
First ground surface, Gb...Second ground surface, Gp...Grinded tip.

Claims (1)

[Scope of Claims] 1. A grindstone head which is rotatably arranged with respect to the bed and is movable relative to the workpiece in a first axis direction perpendicular to the spindle axis and in a second axis direction parallel to the spindle axis. , an angular-shaped grinding wheel having a first grinding surface parallel to the spindle axis and a second grinding surface perpendicular thereto is mounted on the shaft, and the grinding wheel is simultaneously rotated in the first and second axial directions.
In a feed control device for a numerically controlled grinding machine, the grinding wheel is moved relative to the first axis along an oblique path by moving the axis, wherein the grinding wheel is moved relative to the first axis along an oblique path that passes through a set reference point. a grinding angle setting means for inputting and setting a grinding angle indicating a grinding direction of the grinding wheel along the intersection path into a data storage means for storing numerical control data; and the first axis related to the first grinding surface of the grinding wheel. movement command reading means for reading movement command data in the direction from the data storage means; and when the movement command data is an incremental movement amount, adding or subtracting the incremental movement amount to the current position of the grinding wheel in the first axis direction; a first axis end point calculation means for calculating the coordinates of an end point position in one axis direction; and an end point coordinate value calculated by the first axis end point calculation means, the coordinates of the reference point, and the coordinates of the reference point, which are stored in the data storage means. a second axis end point calculation means for calculating the coordinates of the end point position existing on the oblique path in the second axis direction based on the grinding angle; and the end point calculated by the second axis end point calculation means. subtraction means for calculating the deviation between the coordinates and the current position of the second axis as the amount of movement in the second axis direction; and a subtraction means for calculating the deviation between the coordinates and the current position of the second axis; a pulse decomposition means for distributing to the second axis a number of pulses corresponding to the movement amount in the second axis direction calculated by the subtraction means at the same time as distributing to the first axis; Feed control device in controlled grinding machine. 2. Claims characterized in that the grinding angle setting means comprises a keyboard for inputting data of a numerical control device, and a data reading means for inputting the operation state of the keyboard and storing it in the data storage means. A feed control device for a numerically controlled grinding machine according to item 1. 3. The grinding angle setting means comprises an angle sensor that detects the rotation angle of the grindstone, and a data reading means that inputs a signal from the angle sensor and stores the rotation angle of the grindstone in the data storage device. A feed control device for a numerically controlled grinding machine according to claim 1, characterized in that: