JPH03123807A - Measuring device for three-dimensional form - Google Patents

Abstract

PURPOSE:To effectively avoid the lowering of a measuring speed by allowing a single optical measuring device to horizontally move along the arranging direction of a stylus group. CONSTITUTION:The stylus groups 6, 6... are disposed every frame 1 above a model 8. Thereafter, the styli 6, 6... are allowed to simultaneously descend by gravity toward the upper surface of the model 8 by utilizing the engagement of a guide wire 2 with a through hole so that the contacts 6B formed at the lower ends of the respective styli 6, 6... are made to abut on the upper surface of the model 8. As a result, the three-dimensional form of the model 8 is replaced with the staircase-like displacement through the displacement in the vertical direction of the stylus groups 6, 6.... In such a state, the optical measuring device 19B is relatively moved in a horizontal direction with respect to the stylus groups 6, 6... and reflected light from a flat light receiving surfaces 6A formed at the upper ends of the respective styli 6 is consecutively measured. Thus, the lowering of the measuring speed is avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a three-dimensional shape measuring device, and in particular, it is attached to the main shaft of a numerically controlled machine tool to measure a model having a three-dimensional shape, e.g. The present invention relates to an improvement in a measuring means used as a device for measuring the shape of a three-dimensional model such as a molding die fixed on a feeding table.

[Conventional technology]

A contact measuring device shown in Fig. 6 and a non-contact measuring device shown in Fig. 8 are used as means for measuring the dimensions and three-dimensional shape of a model with a three-dimensional shape such as a molding die. .

The contact measuring device (15A) is used by being attached to the main axis of a numerically controlled machine tool, such as a machining center, and includes sensors (16) (17) for measuring the dimensions of the model (8) along the XY force directions. 18) and an element rod (6 ).

To explain the measurement procedure based on FIG. 7, three
Models with dimensional shapes, such as molding mold models (8)
is fixed, and the feed table (
The tip of the stylus (6) is brought into pressure contact with the surface of the model (8) while moving the stylus (20) relatively in the X and Y directions, and the displacement along the two directions is detected while the stylus (6) is constantly in contact with the model. The Z-direction dimension of the mold model (8) is being measured.

On the other hand, the non-contact measuring device (15B) is attached to the optical measuring device (19B) on the main shaft of the numerically controlled machine tool as shown in Figure 8.
It is constructed by attaching. Model (8)
When measuring the dimension in the Z direction of the model (8), as shown in Fig. 4, while moving the feed table (20) relatively in the The three-dimensional shape of the model (8) is measured by projecting light and controlling the reflected light to form an image at the center of the light receiving element.

[Problem to be solved by the invention]

The contact measuring device (15A) keeps the tip of the stylus (6) in constant contact with the surface to be measured of the model (8).
The model (8) is moved in the X direction by the feeding table (20).
Move the model (8) horizontally in the Y direction, adjust the contact pressure and feed speed of the feed table (20) so that the amount of displacement ε of the stylus (6) is constant, and set the position coordinate values of the model (8) in the XY force direction.
The dimension in the Z direction at that position is measured. Therefore, a problem arises in that the measurement speed decreases.

On the other hand, when a non-contact measuring device (15B) is used, the problems observed with the contact measuring device (15A) can be avoided, but as shown in the enlarged view by the white arrow on the left side of Fig. When the inclination angle of the surface to be measured in model (8) becomes large, the reflectance of light rays deteriorates, causing a problem that the desired measurement accuracy cannot be obtained.

[Means to solve the problem]

As a means for solving the above problems, the present invention includes a single optical measuring device attached to the main shaft of a numerically controlled machine tool, and the optical measuring device is installed so as to cover the entire or part of the upper surface of a model having a three-dimensional shape. A frame body is placed below the optical measuring device, and within this frame body, each axis line direction is aligned with the axis line direction of the optical measuring device, and it is vertically movable and aligned and supported in a grid pattern. It consists of a plurality of measurement element rods of the same length with a flat light-receiving surface, and the three-dimensional shape of the model is replaced with a step-like displacement of the plurality of measurement element rods, and the measurement element is measured using the optical measuring device. The object of the present invention is to provide a three-dimensional shape measuring device characterized in that a measuring system for measuring is configured as a flat light-receiving surface at the upper end.

[Effect]

The three-dimensional shape of the model is replaced with a step-like displacement through the vertical displacement of multiple measuring element rods (styli) each having a flat light-receiving surface at the upper end, and optical measurement is performed above the stylus group. The three-dimensional shape of the model is continuously measured by measuring the reflected light from the light receiving surface while moving the device relative to the stylus group in the horizontal direction.

〔Example〕

Fig. 1 is a perspective view of the optical measuring device and the stylus group arranged in the frame, Fig. 2 is an enlarged perspective view of the stylus alone, Fig. 3 is a partial top view of the frame and the stylus group, and Fig. 4
The figure is an enlarged front view of the stylus group, and FIG. 5 is an explanatory diagram of the overall structure and measurement procedure of the device of the present invention. In the following description, the same constituent members as in FIGS. 6 to 8 showing the prior art are indicated by the same reference numerals, and explanations of the same items will be omitted.

The stylus (6) is formed from a narrow rod-shaped body,
The upper end is formed into a flat light receiving surface (6A), and the lower end is formed into a hemispherical measurement contact point (6B). A vertically long through groove (3) is provided in the narrow diameter body of the stylus (6).

A single optical measuring device (19B) is attached to the main axis of a numerically controlled machine tool, such as a machining center.
Below the optical measuring device (19B), there is a frame (1) that stores and supports a plurality of the styli (6) in a vertically movable manner and maintains a grid-like alignment.
) are provided. Inside this frame (1), a plurality of styluses (6), (6), etc. are arranged in alignment along the X direction and the Y direction, and each stylus (6)
A perforated support (4) and a guide wire (2), which function as a guide member when an individual vertical displacement Z is applied to (6)..., are attached. As shown in enlarged views in FIGS. 2 and 4, the guide wire (2) is pushed through a through groove (3) provided in the narrow body of the stylus (6), and is inserted into the hole. support (4
) to perform a positioning guide function when the stylus (6) is displaced in the Z direction. A model having a three-dimensional shape, for example, a molding die model (8), is fixed on a feed table (20) of a numerically controlled machine tool, and this feed table (20) is controlled by a computer ( It is configured to be able to move horizontally with respect to the optical measuring device (19B) according to a measurement program sent out from an optical measuring device (not shown). The size of the opening of the frame (1) is such that the plurality of styli groups (6) (6)... arranged within the frame while maintaining a predetermined arrangement pitch (Po) are model (8).
) is designed to match the planar shape of model (8) so that it can cover the entire upper surface of the model (8). Note that for a large model, a frame (1) for one section divided into a plurality of sections is used, and the measurement is performed by sequentially moving the frame (1) for each section.

Hereinafter, the order of measuring the three-dimensional shape (two-direction degree amount) of a model using the apparatus of the present invention will be explained based on FIG. Above the model (8), the stylus group (6) (6)... is placed on each frame (1), and then, using the engagement between the guide wire (2) and the through groove (3), Stylus (6) (6)...
・ all at once toward the top of the model (8) by their own weight,
A hemispherical contact point (6B) formed at the lower end of each stylus (6), (6), etc. is brought into contact with the upper surface of the model (8) with a predetermined pressing force. As a result, the model (8
) is replaced by a step-like displacement through the vertical direction (Z direction) displacement of the stylus group (6) (6)... In this state, the optical measuring device (19B) is moved relative to the stylus group (6), (6), etc. in the horizontal direction (X direction and Y direction), and the The reflected light from the flat light receiving surface (6A) is continuously measured. The measured value detected by the optical measuring device (19B) is converted into an electrical signal via a conversion circuit (not shown) and sent to the CPU of the computer as measurement data, and is calculated from the position coordinates of each point and the stylus diameter (D). ,
The data is converted into three-dimensional shape data by the offset calculation process previously described and stored in the storage circuit of the computer.

〔Effect of the invention〕

By bringing the hemispherical contact point into contact with the top surface of the model in a simultaneous descent method due to its own weight, the three-dimensional shape of the model is converted into a vertical displacement of the flat receiving surface formed at the top end of the stylus group, thus , the three-dimensional shape of the model is continuously measured by horizontally moving a single optical measuring device along the alignment direction of the stylus group.

As a result, a decrease in measurement speed, which has been a problem with conventional contact-type measuring devices, is effectively avoided.

Furthermore, by forming a flat light-receiving surface on the top of the stylus, the problem of a reduction in the amount of reflected light on a steep slope, which has been a problem with conventional non-contact measuring devices, can be solved.

[Brief explanation of drawings]

Fig. 1 is a perspective view of the optical measuring device and the stylus group arranged in the frame, Fig. 2 is an enlarged perspective view of the stylus alone, Fig. 3 is a partial top view of the frame and the stylus group, and Fig. 4
The figure is an enlarged front view of the stylus group, and FIG. 5 is an explanatory diagram of the overall structure and measurement procedure of the device of the present invention. 6 is a schematic front view of a conventional contact type measuring device, FIG. 7 is a top view of a model, and FIG. 8 is a schematic front view of a conventional non-contact measuring device. (1) -- Frame body, (2) -- Guide wire, (3) -- Penetration groove, (4) -- Perforated support, (6) -- Stylus, (6A) -- Flat light receiving Surface, (8”) - Model, (19B) - Optical measuring device. Patent applicant Osaka Kiko Co., Ltd. Agent Shogo Ehara Figure 5 5B Figure 2 Figure + 5A

Claims (1)

[Claims] (1) A single optical measuring device attached to the main shaft of a numerically controlled machine tool, and a frame placed below the optical measuring device so as to cover the entire or part of the top surface of a model having a three-dimensional shape. A plurality of lenses are supported in the frame body in a manner that they can move vertically and are aligned in a lattice shape with their axial directions aligned with the axial directions of the optical measuring device, and their upper end surfaces are flat light-receiving surfaces. It consists of a measuring element rod of the same length as a book,
3. A measurement system is constructed in which the three-dimensional shape of the model is replaced with a step-like displacement of the plurality of measurement element rods, and the measurement element is measured as a flat light-receiving surface at the upper end of the measurement element with the optical measurement device. Dimensional shape measuring device.