JPH04352006A - Method and device for calculating working dimension - Google Patents

Abstract

PURPOSE:To easily calculate working dimensions capable of attaining working satisfying a specified tolerance. CONSTITUTION:The dimensional allowance tolerances of respective parts of a working shape is calculated (S1, S2) based upon shape information, dimension information and tolerance information and corrected (S3) based upon a working accuracy parameter and then virtual working dimension is set up (S4) within the dimension allowance. The virtual working dimension satisfying the whole tolerance within the dimension allowance is found out (S7) and outputted (S8) as normal working dimension. Thereby even a beginner can calculate the working dimension attaining working satisfying a specified tolerance. Even when a working shape is complex and has many tolerance specifications, the working dimension satisfying the tolerance can easily be calculated.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for calculating machining dimensions, and more particularly, to a method and apparatus for calculating machining dimensions for calculating machining dimensions that realize machining that satisfies specified tolerances.

0002

2. Description of the Related Art FIG. 7 is an explanatory diagram showing a method of creating machining instructions for an NC machine tool using a conventional automatic programming device. The automatic programming device (51) has a keyboard (54) on the front of the main body (52) for inputting shape information and dimensional information regarding the machined shape, and a keyboard (54) for inputting shape information and dimensional information and calculation results input from the keyboard (54). A display device (53) for displaying information is provided.

When creating a machining command using the automatic programming device (51), the operator inputs the machining shape drawn on the drawing and the dimensions such as the length and angle of each part of the machining shape directly into the automatic programming device. (51). For example, when processing into the processing shape (72) drawn in the drawing (71) of FIG.
) to input the machined shape (72), and then input the dimension values (73) and (74) of each part of the machined shape (72) using the keyboard (54). (62) is the machining shape drawn on the display device (53) based on the input machining shape and dimension values, and (63) and (64) are the machining shape drawn on the display device (53) based on the input machining shape and dimension values.
53) These are the dimension values displayed above (“Introduction to NC Programming” by Ryoichiro Nozawa and Hajime Kishi: 1985)
Published by Nikkan Kogyo Shimbun, see pages 175-182)
.

After inputting the machining shape, dimension values, and other machining conditions in this way, the automatic programming device (5)
1) creates a processing command based on the information. Then, the machining command is sent to the NC device to actually perform the machining. After machining is completed, the workpiece is measured to determine whether it meets specified tolerances. If strict tolerances are specified, a workpiece that satisfies those tolerances can be obtained by repeating machining and measurement many times.

[0005]

[Problems to be Solved by the Invention] Obtaining a workpiece that satisfies the specified tolerances using the above conventional method relies heavily on the operator's intuition, and it is difficult for beginners to obtain such a workpiece by programming. There are difficult issues. In addition, even when programming is performed by a skilled operator, there are cases where the machining shape is complex and many tolerances are specified, when the temperature of the material or tool changes rapidly during machining, or when the positioning accuracy of the machine tool is poor. teeth,
There are many cases where the shape of the workpiece does not meet the specified tolerances, and therefore there is a problem in that the machining is often repeated with different dimension values.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method and apparatus for calculating machining dimensions that can calculate machining dimensions that realize machining that satisfies specified tolerances, and that even beginners can perform the calculation. It is in.

[0007]

[Means for Solving the Problems] A method for calculating machining dimensions of the present invention includes the steps of inputting shape information regarding a machining shape, inputting dimensional information associated with the machining shape, and tolerances associated with the dimensional information. Its structural feature is that it comprises a step of inputting information, and a step of calculating processing dimensions that satisfy the tolerance based on the input shape information, dimension information, and tolerance information.

The machining dimension calculation device of the present invention includes a shape information input means for inputting shape information regarding the machining shape, a dimensional information input means for inputting dimensional information associated with the machining shape, and a tolerance information associated with the dimensional information. a tolerance information input means for inputting information; and a tolerance information input means for inputting information based on the shape information input by the shape information input means, the dimension information input by the dimension information input means, and the tolerance information input by the tolerance information input means. A feature of the structure is that it is provided with processing dimension calculation means for calculating processing dimensions that satisfy tolerances.

[0009]

[Operation] In the process dimension calculation method and device of the present invention,
Using the shape information regarding the machined shape, the dimension information attached to the machined shape, and the tolerance information attached to the dimension information, it is possible to calculate the dimensional tolerance range for each part of the machined shape. Therefore, we select an appropriate value within the calculated tolerance range to set provisional machining dimensions for each part, and compare the provisional machining dimensions with the tolerance information to determine whether each part satisfies the specified tolerance. Determine whether If the conditions are satisfied, the temporary machining dimensions are set as the regular machining dimensions. If not, the temporary processing dimensions are changed to other values within the tolerance range, and it is determined whether all tolerances are satisfied in the same manner as above. If not, repeat the same steps. thus,
Machining dimensions that satisfy specified tolerances can be calculated for all parts of the machined shape.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. (Structure) FIG. 3 is a schematic diagram of an automatic programming device for creating machining instructions for an NC machine tool, which incorporates the machining dimension calculation device of the present invention.

The automatic programming device (11) has a keyboard (14) on the front of the main body (12) for inputting shape information, dimension information, and tolerance information regarding the processed shape, and a keyboard (14) for inputting shape information, etc. input from the keyboard (14). and a display device (13) for displaying various information and calculation results. The operator enters shape information, dimension information, etc. on the keyboard (13) according to the instructions displayed on the display device (13).
4) Input and create processing instructions in an interactive format.

FIG. 1 is a block diagram showing the configuration of an embodiment of the processing dimension calculation apparatus of the present invention, and FIG. 2 is a flowchart showing the operation of the processing dimension calculation apparatus. The machining dimension calculation device (1) of the present invention is built into an automatic programming device (11).
11) creates a machining command for the NC machine tool using the machining dimensions calculated by the machining dimension calculating device (1).

As shown in FIG. 1, the machined dimension calculation device (1) includes an information input section (1a) and an information processing section (1b). The information input section (1a) includes a shape information input section (2) for inputting shape information regarding the machined shape, and a dimension information input section (3) for inputting dimensional information accompanying the machined shape.
It consists of a tolerance information input section (4) for inputting tolerance information accompanying dimensional information.

The information processing section (1b) includes a dimension tolerance calculation section (5) that calculates a dimension tolerance based on input shape information, dimension information, and tolerance information, and a dimension tolerance calculation section that calculates a dimension tolerance based on correction parameters. A dimensional tolerance correction section (6) that corrects the dimensional tolerance calculated in (5), a temporary machining dimension setting section (7) that sets temporary machining dimensions within the corrected dimensional tolerance range, and a temporary machining dimension It also includes a tolerance determining section (8) that determines whether the temporary machining dimensions set by the setting section (7) satisfy specified tolerances.

In this embodiment, the information input section (1a) is composed of a keyboard (13) of an automatic programming device (11), and the information processing section (1b) is composed of a microprocessor, and the information is stored in a memory. Information processing is performed according to the programmed program.

Furthermore, in this embodiment, the information processing section (1b)
That is, the dimensional tolerance calculation unit (5), the dimensional tolerance correction unit (6), the temporary processing dimension determination unit (7), and the tolerance determination unit (8).
) constitutes the processing dimension calculation means.

The shape information input unit (2) inputs information indicating what kind of shape the processed shape is to the dimension tolerance calculation unit (
5). This shape information is entered by the operator using the keyboard (14), but shape information output from a CAD system or the like may also be input.

The dimension information input section (3) inputs numerical values indicating the dimensions of each part of the processed shape to the dimension tolerance calculation section 5. This dimensional information can be entered by the operator using the keyboard (1
4), but dimension information output from a CAD system or the like may be input.

The tolerance information input section (4) inputs numerical values indicating tolerances associated with the dimensions of each part of the machined shape to the dimension tolerance calculation section (5). The operator inputs this tolerance information using the keyboard (14), but tolerance information output from a CAD system or the like may also be input.

[0020] As the shape information and dimension information, information that can be input using a conventional automatic programming device (51) is used. Tolerance information includes not only tolerances related to dimensional accuracy such as length (width, height, pitch, diameter, depth, step, depth, etc.) and angle, but also straightness, flatness, roundness, etc. Tolerances related to shape accuracy such as cylindricity, parallelism, perpendicularity, inclination, position, coaxiality, symmetry, and contact are also used.

The dimensional tolerance calculation unit (5) calculates the dimensional tolerance for each part of the inputted machining shape based on the shape information, dimensional information, and tolerance information. That is,
The upper limit value of the tolerance is calculated by adding the upper limit value of the tolerance to the dimension value of each part of the machined shape, and the lower limit value of the tolerance range is calculated by subtracting the lower limit value of the tolerance from the dimension value.

The dimensional tolerance correction section (6) modifies the dimensional tolerance range obtained by the dimensional tolerance calculation section (5) using appropriate modification parameters. As a correction parameter,
The temperature-thermal deformation characteristics of the material to be machined, the jigs, tools, and machine tools used, and the machining accuracy of the machine tools used in the directions of each operating axis are used. By modifying the dimensional tolerance range, machining dimensions can be obtained that realize machining that takes into account parameters such as thermal deformation of materials, jigs, etc., and machining accuracy of machine tools. This modification parameter is stored in the memory of the information processing section (1b), for example.

[0023] Note that the dimensional tolerance correction section (6) is not provided, and the obtained dimension tolerance range is sent as is to the temporary processing dimension setting section (7) without being corrected in the dimensional tolerance calculation section (5). You can.

The temporary machining dimension setting section (7) sets temporary machining dimensions for each part of the machining shape within the dimensional tolerance corrected by the dimensional tolerance correction section (6), and applies the values to the tolerance determination section. (
8). If the tolerance determination unit (8) sends information that "that value does not satisfy all the tolerances," it changes to another value and outputs it again. This operation is repeated until a predetermined number of times is reached. Even if you repeat this operation a predetermined number of times, if you receive information that "that value does not satisfy all tolerances," the operation will be stopped and a message will be displayed on the display (13 ). This display allows the operator to know that there is a discrepancy in the specified tolerances.

There are various ways to set the temporary machining dimensions, but for example, the first step is to select a middle value within the allowable range, and the second time, a value equivalent to 10% of the width of the allowable range is selected as the upper limit of the allowable range. There is a method of selecting a value that is subtracted from the value or a value that is added to the lower limit value, and then increasing the subtracted and added values at the same rate. Other than this method, other known techniques such as linear programming may also be used. In short, any method that uniformly selects values within the allowable range will suffice.

[0026] The tolerance judgment section (8) is a temporary machining dimension setting section (
Enter the temporary machining dimensions set in 7) in the tolerance information input section (4).
It is compared with the tolerance information input from , and it is determined whether the provisional machining dimensions satisfy all specified tolerances. If it is determined that the temporary machining dimension value satisfies all the specified tolerances, the temporary machining dimension value is recognized as the regular machining dimension value, and the value is used to create a machining command for the automatic programming device (11). output to section (15). A machining command creation unit (15) creates a machining command based on the machining dimension values.

When determining that the temporary machining dimension values do not satisfy all specified tolerances, the tolerance determination section (8) sends information to that effect to the temporary machining dimension setting section (7), and the machining command creation section In (15), the temporary machining dimension values are not output. Upon receiving the information that "that value does not satisfy all tolerances," the temporary machining dimension setting section (7) sets another value as the temporary machining dimension and sends it to the tolerance determination section (8), as described above. Output. The tolerance determination section (8) performs the same determination again regarding the new provisional machining dimension values. This determination operation is repeated until the temporary machining dimension setting section (7) stops the operation.

(Operation) Next, the operation of the processing dimension calculating apparatus (1) having the above structure will be explained with reference to FIG. Here, an example will be described in which the machining dimensions of the machining shape shown in FIG. 4 are calculated.

In step S1, the dimensional tolerance calculation unit (
In 5), shape information of the machined shape is inputted using the shape information input section (2), dimension information of the machined shape is inputted using the dimension information input section (3), and tolerance information of the machined shape is inputted using the tolerance information input section (4). do. This input is performed using a keyboard (13) or a CAD device. The tolerance information is also input to the tolerance determination section (8).

[0030] The processed shape (
In the case of 32), the shape information indicating that the upper left corner of the rectangle is missing is input using the keyboard (13) or the like. In addition, as dimension information, the dimension value (33) [150] indicating the height of the processed shape (32), the dimension value (35) [200] indicating the width of the processed shape (32), and the dimension value (35) [200] indicating the angle 37) Enter [150]. As tolerance information, the tolerance value (34) [+0.5, -
0.5], tolerance value (36) specified for dimension value (35)
Input [+0.1, -0.2].

Based on the input shape information, dimension information, and tolerance information, as shown in FIG. (27), tolerance value (24) (26
) is displayed.

In step S2, the dimensional tolerance calculation unit (
5) calculates the dimensional tolerance range of each part by adding or subtracting the input tolerance value to the dimensional value of each part of the input machining shape.

In the case of the processed shape (32) in FIG. 4, the dimension value (
33) and its tolerance value (34), the allowable range of the dimension value (33) is calculated to be 149.5 to 150.5. Similarly, from the dimension value (35) and its tolerance value (36), the dimension value (
35) is calculated as 199.8 to 200.1.

In step S3, the dimensional tolerance correction section (
6) corrects the dimension tolerance range calculated by the dimension tolerance calculation unit (5) using the modification parameter.

When using the machining accuracy of a machine tool as a correction parameter, the correction parameter is set from the machining accuracy information of the machine tool to be used, and the dimensional tolerance range is corrected by the set correction parameter.

For example, when machining is performed using the machine tool (41) shown in FIG.
+0.0 in the X-axis direction as shown in table (42)
1 mm, -0.02 mm in the Y-axis direction, and 0 in the Z-axis direction, for example, in the machined shape (32) of FIG.
9.49 to 150.49, and the tolerance range of dimension value (35) 199.8 to 200.1 is 199.802 to 200.1
Revised to 02.

The table (42) indicating the machining accuracy of the machine tool (41) is stored in a memory, for example, so that it can be accessed when necessary. In this way, the machine tool (4
Since the machining accuracy in 1) is corrected, machining that satisfies the specified tolerance can be easily realized.

When using temperature-thermal deformation characteristics of materials, jigs, tools, machine tools, etc. as correction parameters, a temperature measuring means is attached to all or part of them to measure the temperature during processing. It is configured to measure changes, and the obtained temperature change information and the temperature of those materials -
The thermal deformation status during processing is estimated from the thermal deformation characteristic information and the dimensional tolerance range is corrected.

For example, if the material of the machine tool is different from the material of the raw material, the difference in thermal expansion coefficient between the two materials is used as a correction parameter, and the difference in thermal expansion coefficient and the temperature difference during machining and measurement are used for machining. Calculate the amount of correction for each part dimension by multiplying each part dimension of the shape. In this way, errors due to heat are corrected, so even if the temperature changes rapidly during processing, processing that satisfies the specified tolerance can be realized.

For example, if the material of the machine tool is iron and the material of the material is aluminum, the coefficient of thermal expansion of iron at 20°C is 11.7×10-6, and the coefficient of thermal expansion of aluminum is 23.03×. Since it is 10-6, the difference is 11.
33×10 −6 becomes the correction parameter.

[0041] In step S4, the temporary machining dimension setting section (7
) sets temporary machining dimensions for each part of the machining shape within the revised dimensional tolerances.

[0042] As a method of setting temporary machining dimensions, first select an intermediate value within the allowable range, and second time select a value equivalent to 10% of the width of the allowable range from the upper limit of the allowable range. Alternatively, if we select the value added to the lower limit value and then increase the subtracted and added values at the same rate, the machined shape (32) in Fig. 4 initially shows the height. The tentative machining dimension of dimension value (33) is the intermediate value of 149.9 in the corrected tolerance range of 149.49 to 150.49.
Set to 9. The temporary processing dimension of the dimension value (35) indicating the width is within the corrected tolerance range of 199.802 to 200.1
It is set to an intermediate value of 199.952 between 02 and 199.952.

The second time, 0.10, which is 10% of the width 1.0 of the corrected tolerance range of the dimension value (33) indicating the height, is added to the lower limit value 149.49, or the upper limit value 150.
Set to the value subtracted from 49. Also, a number indicating the width (
35), which is 10% of the width of 0.3 of the corrected tolerance range, is added to the lower limit value 199.802, or set to a value subtracted from the upper limit value 200.102. From the third time onwards, the values are set in sequence by adding or subtracting a value corresponding to 10% of the width of the corrected tolerance range.

In step S5, it is determined whether or not the provisional machining dimensions have been set for the Nth time. This determination is made by the temporary machining dimension setting section (7). The number of times N is set in advance in consideration of the method of setting temporary machining dimensions, etc., and stored in the memory. If it is determined that it is the Nth time, the temporary machining dimension setting unit (7) stops the setting operation (step S6), and displays on the display device (13) that there is a contradiction in the specified tolerance. If it is determined that it is not the Nth time, the process jumps to step S7.

In step S7, the tolerance determining section (8)
It is determined whether the temporary machining dimensions sent from the temporary machining dimension setting section (7) satisfy all specified tolerances. If it is determined that all specified tolerances are not met,
Return to step S4. Then, the temporary processing dimension setting section (7)
Since the temporary machining dimensions are set to other values and output to the tolerance determination section (8), the same determination is performed again.

If it is determined that all specified tolerances are satisfied, the provisional machining dimension values at that time are recognized as regular machining dimensions, and the machining dimensions are output to the machining command creation section (15) (step S8 ). In this way, calculation of processing dimensions is completed.

In the above description, dimensions and tolerances include the lengths of each part of the machined shape and their tolerances, but angles such as corners and circular arcs of the machined shape and their tolerances may also be used. Note that in this specification, "dimensions" refers to a broad concept that includes everything related to the processed shape, such as the length and angle of the processed shape.

[0048]

According to the method and apparatus for calculating machining dimensions of the present invention, it is possible to calculate machining dimensions that realize machining that satisfies specified tolerances, and even a beginner can perform the calculation. Therefore, even if the machining shape is complex and many tolerances are specified, the temperature of the workpiece or tool changes rapidly during machining, or the positioning accuracy of the machine tool is poor, the specified tolerances can be met. It becomes possible to easily calculate processing dimensions.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of a processing dimension calculation device of the present invention.

FIG. 2 is a flowchart showing the operation of the machining dimension calculation device of FIG. 1;

[Fig. 3] NC equipped with a processing dimension calculation device of the present invention
1 is a schematic diagram of an automatic programming device that creates machining instructions for a machine tool.

FIG. 4 is a schematic diagram of a drawing showing an example of a processed shape.

FIG. 5 is a schematic perspective view showing an example of a machine tool.

FIG. 6 is a table showing the machining accuracy of the machine tool in FIG. 5;

FIG. 7 is a schematic diagram of a conventional automatic programming device that creates machining instructions for an NC machine tool.

FIG. 8 is a schematic diagram of a drawing showing an example of a processed shape.

[Explanation of symbols]

1 Processing dimension calculation device 1a Information input section 1b Information processing section 2 Shape information input section 3 Dimension information input section 4 Tolerance information input section 5 Dimension tolerance calculation section 6　Dimension tolerance correction section 7 Temporary processing dimension setting section 8 Tolerance judgment section 11 Automatic programming device 12 Main body 13 Display device 14 Keyboard 15 Processing command creation department 22 Processing shape 23, 25 Dimensions 24, 26 Tolerance value 27 Angle value 31 Drawings 32 Processing shape 33, 35 Dimensions 34, 36 Tolerance value 37 Angle value 41 Machine tools 42 Processing accuracy table

Claims (2)

[Claims] 1. A step of inputting shape information regarding a machined shape, a step of inputting dimensional information associated with the machined shape, a step of inputting tolerance information associated with the dimensional information, and a step of inputting shape information associated with the input shape information. A method for calculating machining dimensions, comprising the step of calculating machining dimensions that satisfy tolerances based on dimension information and tolerance information. 2. Shape information input means for inputting shape information regarding the machined shape; dimensional information input means for inputting dimensional information associated with the machined shape; and tolerance information input means for inputting tolerance information associated with the dimensional information. and calculating processing dimensions that satisfy the tolerance based on the shape information input by the shape information input means, the dimension information input by the dimension information input means, and the tolerance information input by the tolerance information input means. What is claimed is: 1. A processing dimension calculation device comprising processing dimension calculation means for calculating processing dimensions.