JPH11226870A - Numerically controlled work device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate position alignment of a workpiece relating to a tool, and automatically perform work of the workpiece. SOLUTION: This numerically controlled work device 20 is formed in a constitution provided with a work spindle 29 holding a workpiece 28 having a sloped worked surface and rotating it around an axial line, tool hold base 27a, turn table 31, cut-in table 23, and a work spindle table 30. Here, a position correction means 42 is provided, which position-corrects a tool 26 relatively from an arbitrary tool position to a desired tool position by a cut-in amount and a workpiece moving amount in an orthogonal direction to this cut-in. This means 42 is provided with a position arithmetic means calculating a tool cut-in amount and a workpiece moving amount from a distance from the arbitrary tool position along an axial direction of the workpiece 28 to the desired tool position, a distance from the arbitrary tool position orthogonal thereto to the desired tool position, and a relative tilt angle formed by a cut-in direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a numerically controlled machining apparatus for machining a workpiece by numerical control, and more particularly to a grinding machine for grinding a rolling surface or a collar surface of a ring such as a tapered roller bearing inner ring. About the board.

[0002]

2. Description of the Related Art When grinding an inner ring or a flange surface of a tapered roller bearing, grinding is generally performed by cutting a grindstone not obliquely but vertically. Here, there is a conventional grinding machine shown in FIG. The grindstone 2 attached to the rotating shaft of the grinding machine 1 is provided to be slidable in a direction perpendicular to the rotating shaft 3 of the grindstone 2.

A work 4 to be ground is held on an XY table 5 and slides the work 4 in the X direction.
It has a function of a table and a Y table for sliding the work 4 in the Y direction. The X direction is a slide direction in the radial direction of the work, and the Y direction is a slide in the rotation axis direction of the work.

The functions of these X tables and Y tables are as follows:
In order to make both act on the upper surface of the XY table 5,
The components required to perform each function are stacked in two layers, and are stacked on the spindle on the XY table side.

[0005]

By the way, in the above-mentioned grinding of the work 4, the work 4 is inclined with respect to the grindstone 2, so that the cutting amount of the grindstone 2 and the work 4
It is difficult to adjust the amount of movement in the X and Y directions, which requires skill. That is, as shown in FIG.
If it moves along the direction and the Y direction, the distance to the grindstone 2 changes and the cut amount of the grindstone 2 with respect to the work 4 varies.

This is because both the X direction and the Y direction are arranged so as to be inclined by a predetermined angle with respect to the center axis of the grindstone 2, so that it is moved only in one of the X direction and the Y direction. This is because even in this case, the distance from the grindstone 2 varies.

Further, since the mechanism for sliding in the X direction and the Y direction is laminated, the rigidity of the grinding machine 1 is reduced and the cost is increased.

Further, since the slide in the X direction and the Y direction is manual and the cutting amount of the grinding wheel 2 is also manually performed, there is a problem that the skill and intuition must be relied on.

The present invention has been made in view of the above circumstances, and has as its object to provide a numerically controlled machining apparatus capable of easily aligning a work with a tool and automatically processing the work. It is intended to provide.

[0010]

According to a first aspect of the present invention, there is provided a work spindle for holding a work having a work surface inclined with respect to an axis and rotating the work around the axis. A tool holder for holding a tool for processing a surface to be machined of the work, and a relative inclination angle such that one of the work spindle and the tool holder is opposed to the surface to be machined in a direction in which the tool cuts. A numerically controlled machining device comprising: a turning table to be given; a cutting table for moving the tool holding table forward and backward in a cutting direction; and a work spindle table for moving the work spindle in a direction perpendicular to the cutting direction. For the tool, the tool cutting amount from the arbitrary tool position to the desired tool position is relatively Position correcting means for correcting the position by a moving amount of the workpiece that slides in a direction perpendicular to the axial direction of the workpiece and a distance from an arbitrary tool position along the axial direction of the workpiece to a desired tool position. Numerical control, comprising: position calculating means for calculating the tool cutting amount and the workpiece moving amount from a distance from an arbitrary tool position to a desired tool position, and a relative inclination angle formed by the cutting direction of the tool. It is a processing device.

According to the present invention, position correction for correcting a position of a tool relative to a workpiece by an amount of tool cutting from an arbitrary tool position to a desired tool position and a moving amount of a workpiece that slides in a direction orthogonal to the cutting of the tool. Means, wherein the position correction means includes a distance from any tool position along the workpiece axial direction to a desired tool position, and a distance from any tool position orthogonal to the workpiece axial direction to a desired tool position. And a position calculating means for calculating the tool cutting amount and the workpiece moving amount from the tool cutting direction and the relative inclination angle to be formed, so that the driving direction of the work spindle table can be changed in two directions by using the tool cutting direction. From only one direction.

Also in this case, it is possible to reliably control the amount of grinding of the workpiece in the axial direction of the workpiece and in the direction orthogonal thereto by the position correcting means. In addition, it is possible to prevent a change in the distance to the tool, which has occurred when the workpiece is moved in a direction parallel or perpendicular to the axial direction of the workpiece. Is easily adjusted, and this grinding can be performed automatically.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 1, a grinding machine 20 as a numerically controlled processing device has a grinding mechanism 21 and a drive mechanism 22. Grinding mechanism 21
Is provided with a cutting table 23, and the cutting table 23 is configured to interlock with a servomotor 25 as a first driving means via a ball screw 24. The servo motor 25 is provided at a fixed portion.

Therefore, when the servo motor 25 is driven to rotate, the cutting table 23 is driven in the vertical direction (hereinafter, this direction is referred to as the X direction).

A drive motor (not shown) for rotating and driving the grindstone 26 is provided inside the cutting table 23.
The driving force generated by this drive motor is used for rotating the grindstone 26 via the grindstone spindle 27. In addition,
A tool holder 27 a for holding the grindstone 26 is provided at the tip of the grindstone spindle 27.

The grindstone 26 is formed so that its grinding surface has an appropriate curvature. This curvature is, for example, a half toroidal CVT when the work 28 is completed.
This is a special shape for forming a disk, and therefore, the grindstone 26 having the curvature (shape) is cut at a predetermined angle with respect to the work 28.

It is necessary to fix the work 28 to be ground to the cross slide 29 by chucking, and thereafter move the work 28 with the grinding.
There is a drive mechanism 22 as a device for moving the motor 8.
The drive mechanism 22 has a base 30 as a work spindle table, and the base 30 has a turning table 31.
Is provided. Therefore, the inclination angle of the cross slide 29 of the swivel table 31 with respect to the base 30 can be adjusted.

For this purpose, a turning guide 32 for performing a regular turning operation is provided inside the turning table 31. The turning guide 32 is formed, for example, in a groove shape, and guides the turning drive of the turning table 31 to perform the grinding
Has a function of restricting the inclination angle adjusting operation with respect to the cutting axis A of the first motor.

A work spindle (not shown) is provided inside the turning table 31, and the work spindle is driven to rotate about a rotation axis B.

Work 2 fixed to cross slide 29
Reference numeral 8 indicates that the inclination angle can be adjusted by rotating the rotation axis B appropriately with respect to the cutting axis A to form a predetermined angle. By this rotation, the work 28 can be set to a predetermined inclination angle, and is mounted so that the center axis of the work 28 coincides with the rotation axis B in order to correspond to the inclination of the rotation axis B.

The base 3 having the above-described swivel table 31
0 is connected to a servo motor 33 which is a second driving means. The servo motor 33 drives the base 3 in a direction perpendicular to the cutting axis A and in a direction parallel to the grindstone spindle 27 (hereinafter referred to as the Y direction).
0 can be driven.

The servo motors 25 and 33 are connected to drive circuits 40 and 41, respectively.
0 and 41 are both connected to the numerical controller 42.
The numerical control device 42 receives, for example, master data, which is the shape of the workpiece 28 after machining, and actual dimensions of the workpiece 28, and determines the machining amount of the workpiece 28 according to the input values.

The drive circuits 40 and 41 and the numerical controller 42 constitute a position control / correction means. For this reason, a control command is given to the drive circuits 40 and 41 according to the machining amount of the work 28 calculated by the numerical controller 42, and the drive circuits 40 and 41 control the servo motor 2 according to the control command.
The control of the current to be conducted to 5, 33 is performed. Thereby, the movement of the cutting table 23 in the X direction and the movement of the base 30 in the Y direction can be set to desired positions.

The numerical controller 42 is provided with a keyboard 43 for inputting actual numerical values. The numerical control unit 42 can display the positions in the X and Y directions on a display CRT 44.

A drive control method for the grinding machine 20 having the above-described configuration will be described below with reference to FIG. When performing drive control, first, the position (β ₀ ) of the cross slide 29 in the reference work, which is master data after completion, is determined (step 1).

Β ₀ is a distance from the origin of the cross slide 29 (completion point of return to the origin) to the center of the grindstone 26 (the R center of the work 28). Next, in the case of setting change, model number data is input in advance (step 2), and the model number is selected. Based on the reference work data and the model number data, the work size difference ΔY is calculated by the numerical controller 42.
To calculate the distance (β ₁ ) from the origin of the cross slide 29 to the R center of the workpiece 28 in the model number data.

Here, the reference work data is a fixed value because it is used every time the set is changed. Further, the model number data can be input, and can be stored, for example, up to sixteen.

Thereafter, the work 2 as shown in FIG.
Then, each element of the master data No. 8 is compared with each element of the model number data (step 3). In comparison, each element may be input at this stage, or may be input in advance.

As elements of each data to be input, in the master data, a dimension between the R centers of the work 28 (D ₀ ), a height of the work 28 at the R center (H ₀ ),
The R center diameter (R ₀ ) of the work 28 and the groove bottom height (B ₀ ) of the work 28 are input or input in advance. The model number data elements for the master data correspond to the dimensions of the master data (D ₁ ), the height at the R center (H ₁ ), and the R center diameter (R ₁ ), the groove bottom height (B ₁ ) is input or input in advance.

After inputting the master data and the actual size data, the difference between them is calculated to calculate how much the workpiece 28 is actually ground. That is, Δ in the following equation
h and Δd are calculated respectively (step 4).

Δh = H ₁ −H ₀ Δd = 1/2 × (D ₁ −D ₀ ) However, the work 28 is located on the chuck surface of the turning table 31 provided at a predetermined angle with respect to the cutting axis A. Since it is mounted, all the values calculated at this stage are the grinding amounts along the inclined direction, not the grinding amounts along the X direction and the Y direction.

Therefore, in order to convert the amount of grinding along these directions into the following formulas, the X direction and the Y amount are respectively substituted.
It is calculated by converting it into the grinding amount in the direction (step 5). Δx = (Δh + Δd × tan θ) × cos θ Δy = (Δd / cos θ) −Δx × tan θ After calculating these values, the workpiece 28 is ground, but the initial processing is temporary grinding by manual jog / step operation. (Step 6). When performing this temporary grinding, the turning table 31 is set in a state where the grindstone 26 is set at an appropriate position and the slide amount of the base 30 is also set appropriately.
Is turned. Thereby, the work 28 having a disk shape and a special shape can be processed.

After the provisional grinding is completed, the dimensions of the work 28 after the completion of the provisional grinding are measured corresponding to the respective elements of the master data, and these values are inputted (step 7). Elements that are measured and input include the dimension between the R centers (D ₁ ′), the R center diameter (R ₁ ′), and the groove bottom height (B ₁ ′). Note that the R center diameter (R ₁ ′) has the same value as the previously input R center diameter (R ₁ ), and the input can be omitted.

Then, in order to correct the table cloth slide after the temporary grinding of the work 28, this correction amount is obtained. The method of calculating the correction amount is as follows. First, the R center height (H ₁ ′) obtained by provisional grinding is calculated based on the groove bottom height (B ₁ ′) and the R center diameter (R ₁ ′) of the work 28 that has been provisionally ground. It is calculated by the following equation (step 8).

H ₁ ′ = B ₁ ′ + R ₁ Also, R ₁ ′ = R ₁ , and the R center diameter (D
Dimension differences Δh ′ and Δd ′ between the model number data are calculated from ₁ ′) and the height of the R center (H ₁ ′). Δh ′ and Δd ′ are
It is derived by the following equation (step 9).

Δh ′ = H ₁ ′ −H ₁ Δd ′ = １ ／ × (D ₁ ′ −D ₁ ) Based on the values of Δh ′ and Δd ′, the cross slide 29
Are calculated (step 10).

ΔX ′ = (Δh ′ + Δd ′ × tan θ) × cos θ = ｛(B ₁ ′ + R ₁ −H ₁ ) + ／ × (D ₁ ′ −D
₁ ) × tan θ｝ × cos θ ΔY ′ = (Δd ′ / cos θ) −ΔX ′ × tan θ = １ ／ cos θ × (D ₁ ′ −D ₁ ) −ΔX ′ × tan
θ The correction amounts ΔX ′ and ΔY ′ of the cross slide 29 are obtained by the above formula, and the grinding amounts ΔX and ΔY of the cross slide 29 are accurately calculated by the following equation (step 11).

.DELTA.X = .DELTA.x + .DELTA.X'.DELTA.Y = .DELTA.y + .DELTA.Y 'Based on the result of the calculation, the position of the cross slide 29 is accurately corrected, and the turning table 31 is driven to rotate and the grindstone 26 is aligned to perform the work 2.
When the processing of No. 8 is started again (step 12), the dimension adjustment is completed, and accurate processing can be performed on the work 28.

According to the grinding machine 20 and the grinding method described above, the above-mentioned inclined and fixed work 28 is driven in the Y direction and the grindstone 26 is driven in the X direction. The grinding of the work 28 can be performed by adjusting the drive along the X direction and the Y direction.

For this reason, in the direction along the cross slide 29, adjustment in two directions was required. However, the slide adjustment of the work 28 side is performed by driving the base 30 in only one direction by the servo motor 33, and further, the servo motor The work 2 is adjusted by adjusting the feed amount of the grindstone 26 with the work 25.
8 can be freely controlled.

Since the servo motor 33 is slidable in the direction perpendicular to the grindstone 26, the relative distance between the work 28 and the grindstone 26 does not change even when the work 28 is moved by the servomotor 33. .

Thus, by moving the work 28 and driving the grindstone 26 to slide, the work 28 can be automatically ground without any skill. Therefore, it is possible to easily perform the grinding.

Further, since the mechanism for sliding the grinding machine 20 is only required in one direction, the mechanism of the grinding machine 20 is simplified, and the cost can be reduced. Further, even in a process in which the work 28 and the grindstone 26 interfere with each other, the process can be performed automatically and without any skill. As in the case of the processing method, it is possible to carry out automatically without skill. For this reason, the degree of freedom of processing is improved, which further contributes to the mechanization of processing special shapes.

The embodiment of the present invention has been described above, but the present invention can be variously modified in addition to the above. This is described below. In the above embodiment, the embodiment of the grinding machine 20 has been described. However, the present invention can be applied to other processing apparatuses, for example, a milling machine for performing cutting.

The surface to be ground of the grindstone 26 is not limited to the shape shown in the figure, and is not limited to one having a substantially semicircular cross-sectional shape.
Various shapes are conceivable depending on the shape. In addition, various modifications can be made without departing from the scope of the present invention.

[0046]

As described above, in the present invention, the driving direction of the work spindle table can be reduced from two directions to only one direction by using the cutting direction of the tool. Even in this case, it is possible to reliably control the amount of grinding of the workpiece in the axial direction of the workpiece and in the direction orthogonal thereto by the position correction means.

Further, it is possible to prevent a change in the distance to the tool caused when the workpiece is moved in a direction parallel or perpendicular to the axial direction of the workpiece. The grinding amount can be easily adjusted and the grinding can be automatically performed.

[Brief description of the drawings]

FIG. 1 is a side view showing a configuration of a grinding machine according to an embodiment of the present invention.

FIG. 2 is a diagram showing shapes of a workpiece according to the embodiment before and after processing, and showing a relationship between dimensions before and after processing.

FIG. 3 is an exemplary flowchart showing a procedure of processing the work according to the embodiment;

FIG. 4 is a side view showing a configuration of a conventional grinding machine.

[Explanation of symbols]

 Reference Signs List 20 grinding machine 21 grinding mechanism 22 driving mechanism 23 cutting table 25, 33 servo motor 26 grinding wheel 28 work 29 cross slide 30 base 31 turning table 42 numerical control circuit

Claims (1)

[Claims] 1. A work spindle for holding a work having a work surface inclined with respect to an axis and rotating the work around the axis, a tool holding table for holding a tool for working the work surface of the work, A turning table that gives a relative inclination angle so that one of the work spindle and the tool holding table is opposed to the direction in which the tool cuts with respect to the surface to be machined; A work spindle table that moves the work spindle in a direction perpendicular to the cutting direction.In a numerically controlled machining apparatus, the tool cut amount is set relative to the work from an arbitrary tool position to a desired tool position. Position correction means for correcting the position based on the amount of movement of the workpiece that slides in a direction perpendicular to the cut of the tool Has a distance from an arbitrary tool position along the axial direction of the workpiece to a desired tool position, and a distance from an arbitrary tool position orthogonal to the axial direction of the workpiece to the desired tool position. And a position calculating means for calculating the amount of tool cut and the amount of workpiece movement from the direction of cutting of the tool and the relative inclination angle to be made.