JPH02167649A - Work device - Google Patents

Abstract

PURPOSE:To perform shaping with high accuracy and high efficiency without detaching the body to be worked from a work device, by providing plural displacement gages on a work device, measuring a prework shape by its finite difference and constituting so as to use the same displacement gage even during working. CONSTITUTION:In case of output values being taken IA, IB by retreating a tool 1 to the position not brought into contact with the body 6 to be worked and providing two displacement gages 2a, 2b apart by (d), the deformation is cancelled by respectively containing in IA, IB even in case of a table 4 being deformed and taking the difference in the output values IA, IB and only the shape differences of two points of the body 6 to be worked apart by (d) is shown. Also the section of d<=x<=2d can be defined by a primary reference face o<=x<=d and the output values IA, IB and the whole shape can be defined. Control cutting is then performed with high accuracy by using the displacement gage 2a with the prework shape as the reference.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a processing device such as a cutting device for high-precision cutting of a large diameter and long processing tube.

[Conventional technology]

FIG. 3 is a configuration diagram showing the main parts of a conventional cutting device, as shown in, for example, page 41 of the Proceedings of the Kansai Region Periodical Academic Lectures of the Japan Society for Precision Engineering in 1988.

In the figure, +11 is the tool, (2) is the displacement meter, and (3) is this tool (1).

A displacement meter (2) is attached, and a tool (1) and a displacement meter (2) are attached.
), (4) is a table to which this micro-movement device is attached, and (5) is an arrow indicating the direction of movement of this table (4). (6) is the workpiece, (Sa) is the pre-machined surface before machining, (6b
) is the finished surface after cutting, (7
) is a computer that memorizes the shape of the pre-machined surface (6a) and the target machining shape to be machined, and also calculates the minute movement amount based on the output value of the displacement meter (2) and gives instructions; ) is a drive amplifier that amplifies the command from the computer (7) and supplies voltage to the micro-movement device.

Next, a cutting method will be described in which the distance between the tool (1) and the workpiece (6) is changed based on the previously machined surface (6a), and the depth of cut of the tool is corrected in accordance with the change.

FIGS. 4 and 5 are explanatory diagrams of the above cutting method.

The above cutting method attempts to create a shape by monitoring the actual depth of cut E(X)e relative to the required removal amount R(x). That is, E(x) and R(x)
By correcting the fine cutting tool rest in real time so that they match, it is possible to finish the target shape. here,
Assuming that P(X)e is the pre-processing shape and To(x)f is the target processing shape.

The correction amount δ(,) is expressed by the following formula.

δ(x) = R(x) −E (x)= (P(x)
-To(x) ) E(x) '... ■Therefore, if you accurately understand the pre-processing shape P (x) and measure the actual cutting depth it E (x)k in-process, the correction amount δ( , ) can be obtained.

The actual depth of cut E (x) is as shown in Fig. 5. Assuming that the relative positional relationship between the displacement meter (2) and the tool cutting edge does not change, let this distance be L, and the output value of the displacement meter! It can be obtained from (1).

E(x) = P(x) −(P(x+s)+I(t)−
L) ... ■Here, L is the relative distance in the Y-axis direction between the measurement standard of the displacement meter (2) and the cutting point, and S is the relative distance of the displacement meter (2) in the Y-axis direction.
The relative distance in the X-axis direction of the cutting point from the measurement standard of 2), I(t) is the distance from the measurement standard of displacement meter (2) to the workpiece (6
) is the distance in the Y-axis direction.

Next, by substituting the formula
To(x)=■.

The correction amount δ(x) is required to finish the target machining shape To(x).
Since is always 0, the displacement meter output at each point must be as follows.

I(t):To(x)+LP(X+3)
'... (2) If the depth of cut is controlled so that I(t) satisfies the formula (2), it is possible to finish the target machining shape To(x).

Therefore, j? Therefore, in order to finish the target processed shape To(x)K with high precision, high-precision shape measurement of the pre-processed shape P (x) is essential. Pre-processing shape P (x)
is measured by another shape measuring device, and is memorized by inputting the pre-processed shape P (X)' of the pre-processed surface (6b) of the workpiece measured by this other shape measuring device into the computer (7). be done.

Using that P (x), calculate
s, is calculated by the machine (7), and is passed through the drive amplifier (8) to give a command to the minute movement device (3).

[Problem to be solved by the invention]

The conventional cutting equipment mentioned above does not have a shape measurement system for the pre-processed surface, and uses a separately installed shape measuring device to measure the shape of the pre-processed surface.
The pre-processing shape p (x) must be found.

Therefore, it is necessary to move the workpiece between the separately installed shape measuring instrument and the cutting equipment, and the workpiece becomes larger in diameter.
As the weight increases, the time and effort required to move it increases.

Furthermore, even if the shape measuring device measures the shape with high accuracy, there is a drawback that the repeatability of chucking the workpiece to the cutting device described above may lead to processing errors.

In addition, even when measuring on-machine without removing the workpiece, the pre-processed shape can be measured using a displacement meter that detects the relative distance between the workpiece and the tool during cutting, and other shape measurement systems using a different displacement meter. If 6111 is constant, there is a drawback that the difference in sensitivity and accuracy between the two displacement meters becomes a machining error.

The present invention has been made to solve such problems, and it is possible to measure the shape of the pre-machined surface without attaching or detaching the workpiece from the processing device, and it also uses a displacement meter that is the same as that used during machining. The object of the present invention is to provide a processing device equipped with a measuring means that can cancel measurement errors caused by a displacement meter.

[Means to solve the problem]

The processing device according to the present invention is used for measuring the shape of a pre-processed surface.
A plurality of displacement gauges attached in a row in the machining direction, a means for moving the plurality of displacement gauges and calculating a machined surface shape based on the output, and at least one displacement gauge among the plurality of displacement gauges. It is equipped with means for carrying out actual machining operations.

[Effect]

Since the processing device according to the present invention has a pre-processing shape measuring means, the workpiece can be easily removed from the processing device without being attached to or removed from the processing device.
The pre-machined shape is measured using the same displacement meter that can measure the pre-machined shape and also detects the relative distance between the workpiece and the tool during machining, so there is no reproducible measurement error caused by displacement meters. can also be canceled and a highly accurate shape can be obtained.

〔Example〕

FIG. 1 is a block diagram of the main parts of a cutting device showing one embodiment of the present invention, and FIG. 2 is an explanatory diagram of a measuring method.

In addition, in FIG. 1, (ri to (8)) are the same or equivalent parts as in the conventional device.

However, (2a) and (2b) are displacement meters, and one is installed on each side of the tool (1) in the - row in the advancing direction (5) of the table (4). And those two displacement meters (
The distance between 2a) and (2b) is d.

(7) is a calculator that has the function of calculating the pre-machined surface shape and table straightness based on the two outputs of the solid displacement meter (2) in addition to the function of the calculator of conventional cutting equipment. It is.

Next, a method of measuring the pre-processing collapse shape of the zero-cutting machine will be explained with reference to FIG.

In this processing apparatus, the entire length of the processing surface for measuring the pre-processed shape P (x) is scanned three times by moving the table (4).

Therefore, even if there is a distance variation μ due to table scanning between the workpiece (6) and the table (4), the method must be able to measure the shape with high accuracy without being affected by this.

As shown in Figure 2, two displacement gauges (2a) and (2b)
are set apart by d. Displacement meter (2aX2b)
Let the outputs of be IA and , respectively. The difference between IA and twist indicates the difference in shape between two points separated by d on the workpiece (6).

Even if table (4) is deformed by μ.

μ is included in each of IA, ■B, )A, j
By taking the difference in B, U is canceled and, as described above, only the shape difference between two points separated by d on the workpiece (6) is shown.

Next, we will explain how to measure the overall shape. Workpiece (6
) is the primary reference plane of the metal plate from position 0 to d in the X-axis direction, and if this primary reference plane (0≦X<d) is known, then xl (d≦X2 < 2d) The shape of the point r
(X2) is xl(o≦x1×d, x2=x 1 +a
) using the known f(xl)
The interval of d≦x(2d) can be determined by the output value of JB. Furthermore, the interval of d≦x(2d can be determined by @2
The 0th order 2d≦x (5d) can be fully determined as the next reference plane, and by sequentially moving the reference planes, the entire shape can be determined.

That is, even if table (4) with poor straightness is used.

The two displacement gauges (2a) and (2b) are installed in the negative row in the table advancing direction (5), and the above-mentioned calculation process is performed to measure the entire formed gold.

This section describes the cutting procedure using the cutting device configured as described above.

First, the pre-processed shape P (x) is measured by scanning the table with the two displacement meters (2a) and (2b) as described above. At this time, the tool fil is the workpiece (6)
With the tool in a position where it does not come in contact with the housing, use the table (4) or the micro-movement device (3) to move the tool +In'' backward.

Next, the pre-processed shape P (X) 'e of this measurement result is used as the reference.

Perform controlled cutting. Regarding controlled cutting techniques.

This is the same as the conventional method, and in this case it is carried out using a displacement meter (2a).

In the above embodiment, one displacement meter is installed on the left and right sides of the tool.
Although a total of two are used, two may be attached in the direction of tool movement, or more may be used to improve accuracy.

Moreover, the six-piece cutting device can also be used to measure the shape of finishing machining.

Further, the specifications of the displacement meter (2) and the minute movement device (3) may be determined as appropriate depending on the required accuracy.

Further, in the above embodiments, the cutting device was used as a metal cutting device, but other processing devices that process shapes may be used.

〔Effect of the invention〕

In the present invention, a processing device is provided with a plurality of displacement gauges, the pre-processed shape is measured by the difference between the two, and the same displacement gauge is used during processing. Can measure pre-processed surfaces. Furthermore, differential calculations can cancel all errors during measurement, and since the same displacement meter is used during machining and measurement, measurement errors caused by the displacement meter can also be canceled, resulting in shape machining with high accuracy and efficiency.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the main parts of a cutting device showing one embodiment of the present invention. FIG. 2 is an explanatory diagram of the measurement method. FIG. 3 is a configuration diagram showing the main parts of a conventional cutting device. FIGS. 4 and 5 are explanatory diagrams of the controlled cutting method based on the previously processed surface. In the figure, 11) is a tool, (21, (2a), (2
b) is a displacement meter. (3) is a minute movement device, f41tr! , table, (6
) is the workpiece. (7) is a computer, and (8) is a drive amplifier. inside. show. In each figure. The same symbols indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] (a) means for comparing the pre-machined shape of the workpiece before machining with the target machining shape as a machining target to determine the amount of machining required for the workpiece during machining; (b) ) Machining that has means for measuring the relative position to the workpiece during machining using a displacement meter, comparing the actual machining amount determined from this relative position with the required machining amount determined by the above means, and correcting the machining position. A processing device characterized by comprising the following elements: (c) A plurality of displacement meters arranged in the direction of processing and outputting the relative position with respect to the workpiece. (d) Means for moving the plurality of displacement meters along the machining surface and determining the pre-machined shape before machining from the output relative positions. (e) Means for correcting the machining position by measuring the relative position with respect to the workpiece during machining using at least one displacement meter among the plurality of displacement meters.