JPH0647633Y2 - Automatic tool length measuring device - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a numerically controlled machine tool (hereinafter referred to as NC machine tool).
The present invention relates to a tool length automatic measuring device used for.

[Prior Art] Conventionally, an NC machine tool having an interactive automatic programming function generally performs the following work.

First, as shown in FIG. 9, a machining process will be considered based on the drawing (step S1). Next, touring is decided (step S2) and a program is created (step S3). Attach the tool to the tool magazine as shown in the tooling diagram (step S4). Measure the tool length and perform centering (Step S
Five). Finally, the work is processed (step S6).

The tool length is measured in step S5 as follows.

As shown in FIG. 10, a tool is attached to the spindle, but in order to machine the work, it is necessary to know the exact positions of the work and the tool. For that purpose, it is necessary to measure the length of the tool.

Further, it is necessary to measure the tool length after machining because it is possible to detect wear and breakage during machining by the change in tool length before and after machining.

Fig. 11 shows different types of tools and different shapes of cutting edges.
The mode in which the tool length is measured is different. FIG. 11 (a) shows a state in which the drill or center drill 100 is relatively moved to the contact type sensor 20 installed in the machine and the length thereof is measured. FIG. 11 (b) shows the end mill 300, the sensor 20
It shows a state in which the length is measured by moving it relative to.
FIG. 11C shows how the face mill 400 is moved relative to the sensor 20 and its length is measured.

To perform relative movement of these tools, a manual method and an automatic method are known.

[Problems to be Solved by the Invention] However, the manual method is troublesome because the operator needs to bring the tool cutting edge to the sensor 20 every time the tool length is measured.

In addition, regarding the automatic method, it is difficult to measure all the tools fully automatically. That is, in a tool such as the drill 100 shown in FIG. 11 (a), in which the tool edge is at the center of the spindle, the center of the spindle and the center of the measuring surface of the sensor may be aligned and the blade edge of the tool may be lowered onto the measuring surface of the sensor. However, in the case of the end mill 300 of FIG. 11 (b), there is a cutting edge on the outer peripheral portion of the tool, so it is necessary to shift the tool radius and then lower it. In the case of the face mill 400 of FIG. 11 (c), Since there is a cutting edge on the outer circumference of the tool and the distance between the blade in the circumferential direction is larger than the diameter of the measuring surface of the sensor, the sensor 20
It is necessary to bring the cutting edge 400a to the center of the measurement surface of and align it. Therefore, complicated settings are required to perform these operations.

The present invention has been made in view of the problems of the above-mentioned conventional tool length measuring technique,
An object of the present invention is to provide an automatic tool length measuring device capable of automatically measuring the tool length with a simple configuration even for a tool having no cutting edge at the center of the spindle.

[Means for Solving Problems] The present invention is a tool for a numerically controlled machine tool in which a rotary tool without a cutting edge at the center of a spindle can be mounted and rotation of the spindle can be stopped at a predetermined fixed position. A long automatic measurement device, a tool file storage means for storing at least information regarding a distance and a direction from the center of the spindle in a state where the tool blade edge when mounted on the spindle is in the spindle rotation fixed position stopped state, A reading means for extracting and outputting the information from the tool file storing means, and based on the output of the reading means, the cutting edge of the rotary tool mounted on the spindle is opposed to the measuring surface of the tool length measuring sensor, and then, Axial movement control means for outputting a signal for relatively axially moving the rotary tool or the sensor for measuring the tool length until the cutting edge comes into contact with the measurement surface, and its axial movement control Drive means for driving the rotary tool or the sensor for measuring tool length based on the output of the step, and tool length calculating means for calculating the tool length based on the positional relationship between the output signal from the sensor for measuring tool length and the spindle. It is an automatic tool length measuring device equipped with.

[Operation] In the present invention, for example, after the machining is completed, the rotation stop position of the spindle is set to a predetermined fixed position, and then the reading means retrieves the distance and direction information of the rotary tool from the tool file storage means. Based on the information, the axis movement control means outputs a signal for relatively moving the cutting edge of the rotary tool attached to the spindle to a substantially central position facing the measurement surface of the tool length measuring sensor, and the driving means, The spindle is moved relative to the signal. The tool length calculation means outputs the tool length from the position of the spindle at that time based on the signal from the sensor.

[Embodiment] The present invention will be described below with reference to the drawings showing an embodiment thereof.
explain.

FIG. 1 is a block diagram showing an embodiment of the automatic tool length measuring device according to the present invention, and FIG. 2 is a perspective view of the automatic tool length measuring device according to the present invention.

The tool file storage means 1 is, for example, a magnetic bubble memory, a semiconductor memory, a magnetic disk, or the like, which stores at least information about the distance and the direction of the cutting edge of the tool from the center of the spindle in the fixed state of the spindle rotation fixed position.

This information is, for example, in a boring tool having a cutting edge at a position shifted by the tool radius from the center of the spindle as shown in FIG. 3, the angle formed by the line connecting the cutting edge 10 of the tool and the spindle center 11 with the X axis ( Direction) θ and distance r from its spindle center 11
Is. Alternatively, the position of the cutting edge 10 may be captured with reference to a location having a fixed positional relationship with the center of the spindle.

FIG. 4 shows a case of a tool having a large number of blades at a position shifted by the tool radius from the center of the spindle, in which case information on any one blade is stored.

In the tool file storage means 1, in addition to the above information, tool specifications as shown in FIG. 6 are set.

That is, the name of the tool, the material of the cutting edge of the tool, the tool length correction H code which is the tool length correction number used, the diameter correction D code which is the tool diameter correction number used, the small diameter which is the tip diameter of the chamfering tool, the tool The number of blades, the corner angle of the cutting edge of the tool, the blade edge position correction value, etc. are also set.

The reading means 2 reads the tool file storage means 1 from
It is a means for reading information regarding the distance and direction from the center of the spindle of the tool cutting edge. When the storage means 1 is a magnetic bubble memory or a semiconductor memory, the reading means 2
Is a computer, and for magnetic disks,
A computer system including a magnetic head.

The axis movement control means 3 is based on the output of the reading means 2,
It is a means for outputting a signal for relatively moving the cutting edge 10 of the tool 6 attached to the spindle 5 to a position on the table which comes into contact with the tool length measuring sensor 8. Here, the meaning of relatively moving the cutting edge 10 of the tool 6 to a position in contact with the sensor 8 means that the tool 6 is actually moved and the tool 6 is stationary while the sensor 8 It also means the case of moving a table or the like on which it is placed. Or, it is a case where the movements of both are combined. Reference numeral 13 in FIG. 2 is a spindle head incorporating the spindle 5, a spindle drive motor (not shown), and the like.

The drive means 4 is a means such as a servo motor which relatively moves the spindle head 13 in the X, Y and Z axis directions shown in FIG. 10 based on the output signal of the axis movement control means 3.

The tool length calculation means 9 is a means such as a computer for calculating the tool length based on the output signal when the tool edge contacts the measurement surface of the sensor 8 and the position of the spindle. The position of the main shaft is, of course, a relative position with respect to the sensor 8.

A plurality of types of tools are prepared, the tool file storage unit 1 stores a plurality of types of information, the reading unit 2 sequentially reads the information of each tool 6, and the axis movement control unit 3
May sequentially move each tool 6 to a position where it contacts the sensor 8 and measure each tool length.
In FIGS. 1 and 2, 7 is an automatic tool changer (ATC) in which a plurality of various tools are set.

Next, the operation of the embodiment when the automatic tool length measuring device of the present invention is incorporated in an interactive NC machine tool will be described.

FIG. 5 is a flow chart for explaining the operation flow of the embodiment.

First, the above-mentioned various information is set in the tool file storage means 1 for the type of tool to be used (step S
1). FIG. 6 shows a screen of the display showing the setting. That is, a tool number is assigned to each tool, and a tool name, nominal diameter, material, T code, length correction H code, diameter correction D code, small diameter, number of blades, angle, blade edge position correction, etc. are input by the operation panel keyboard. Go. 14 is a picture screen for facilitating the setting.

Next, an NC program is interactively created based on the machining drawing (step S2). In it, we will identify the necessary tooling. As a result, the tool correction length of each tool is set as H1, H2, etc.

This program is simulated and the drawing is checked to correct the program (step S3).

When the program is completed in this way, the tool designated by the program is then displayed on the screen for confirmation as shown in FIG. 6 (step S4). Next, the tool is set in the pot of the tool magazine in the automatic tool changer 7 corresponding to the tool number (T code) (step S5).
Further, as shown in FIG. 8, among those tools, the tool whose tool length is to be measured is selected and the order is designated (step S
6).

After doing this, the start of tool length measurement is instructed (step S7).

When the start of the tool length measurement is instructed, the reading means 2
Information (angle θ and radius r) regarding the distance and direction from the center of the spindle of the cutting edge of the tool 6 mounted on the spindle 5 when the spindle rotation fixed position is stopped is read from the tool file storage unit 1.

Next, the axis movement control means 3 outputs a signal for relatively moving the cutting edge of the tool 6 mounted on the spindle 5 to a position where the tool length measuring sensor 8 comes into contact with the tool based on the output of the reading means 2. For example, first, the spindle 5 that has been returned to the Z-axis origin is relatively moved so that the center of the spindle 5 is located above the measurement surface of the sensor 8, and then based on the information of the angle θ and the radius r. , A signal for moving the cutting edge of the tool 6 relatively to a position above the measurement surface of the sensor 8 and then lowering the spindle 5 directly below.

The drive means 4 relatively moves the spindle 5 based on the output signal of the axis movement control means 3. When the cutting edge of the tool 6 contacts the measurement surface of the sensor 8, the sensor 8 outputs a touch signal.

The tool length calculation means 9 calculates the tool length based on the output signal from the sensor 8 and the position (Z-axis coordinate) of the spindle 5 at that time. The position of the spindle 5 (Z-axis coordinate) can be derived based on a signal from the axis movement control means 3.

Next, when the length of one tool is measured, the tool to be measured next is taken out from the tool magazine 7 and replaced,
Furthermore, the tool length is measured.

In this way, after all the required tool lengths have been measured, machining of the work is started (step S8).

[Effect of the Invention] As is clear from the above description, in the present invention, the stop position of the rotation of the main shaft is set to a predetermined fixed position, and then the main shaft rotation fixed position is stopped. In advance, the tool file storage means stores the information about the distance and direction of the cutting edge when the spindle rotation is stopped at a fixed position.By using this information, the tool length can be calculated for tools without a cutting edge at the spindle center. It can be measured automatically.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of an automatic tool length measuring device according to the present invention, FIG. 2 is a perspective view of the same embodiment, and FIG.
4 is a plan view for explaining the distance and direction of the tool edge of the same embodiment, FIG. 4 is a plan view for explaining the distance and direction of another tool edge, and FIG. 5 is the operation of the same embodiment. Flowchart shown in FIG. 6, front view of screen for setting tool information of the embodiment, FIG. 7, front view showing list of tools used in the embodiment, and FIG. 8 are tools in the embodiment. Fig. 9 is a front view of the length measurement screen, Fig. 9 is a flowchart showing a conventional work machining process, Fig. 10 is a perspective view of a conventional NC machine tool, Fig. 11 (a) is a front view of a drill and a sensor,
FIG. 11B is a front view of the end mill and the sensor, and FIG. 11C is a front view of the face mill and the sensor. 1 ... Tool file storage means, 2 ... reading means 3 ... axis movement control means, 4 ... driving means 5 ... spindle, 6 ... tool, 7 ... tool magazine 8 ... sensor, 9 ... tool Long calculation means

Claims (2)

[Scope of utility model registration request] 1. A tool length automatic measuring device for a numerically controlled machine tool, wherein a rotary tool having no cutting edge at the center of a spindle can be mounted, and rotation of the spindle can be stopped at a predetermined fixed position. And a tool file storage means that stores at least information about the distance and direction from the center of the spindle in the state where the spindle rotation fixed position is stopped, when the tool blade is mounted on the tool file storage means, and the information is retrieved from the tool file storage means. A reading means for outputting, and based on the output of the reading means, the blade tip of the rotary tool mounted on the spindle is opposed to the measurement surface of the tool length measuring sensor, and then the rotary tool is brought into contact with the measurement surface. Alternatively, based on the output of the axis movement control means for outputting a signal for relatively axially moving the sensor for measuring the tool length, and the rotary tool, Or a driving means for driving a tool length measuring sensor, and a tool length calculating means for calculating a tool length based on a positional relationship between the output signal from the tool length measuring sensor and the spindle. Automatic tool length measuring device. 2. A plurality of types of rotary tools are prepared, and the tool file storage means stores a plurality of types of information,
The reading means sequentially reads the information of each rotary tool, and the axis movement control means sequentially sequentially moves the blade edge of each rotary tool to a position in contact with the tool length measuring sensor, and the tool length calculation means. Claims the utility model registration claim characterized in that the length of each rotary tool is calculated in sequence.
Item automatic tool length measuring device described in paragraph.