JP2524937Y2 - Linear scale - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear scale for detecting a scale pattern recorded on the surface of a scale by a detection head and measuring the displacement of the detection head based on the detection signal.

[0002]

2. Description of the Related Art In recent years, in machine tools and various measuring instruments,
A linear scale (for example, a magnetic scale) for measuring a position and a length is used. The linear scale includes, for example, a magnetic scale rod having a magnetic recording medium formed on a surface thereof, and a detection head for reading a magnetic scale recorded on the scale. On the magnetic scale rod, equally spaced magnetic scale patterns are recorded in advance. The detection head detects the magnetic scale from this magnetic scale rod, and the displacement (movement amount) of the detection head
Is picked up by an electric signal.

[0003] Such a linear scale is usually shown in FIG.
A magnetic scale rod is housed in a frame 10 as shown in FIG. 1 and a carriage unit 11 for moving the detection head relative to the scale is provided. The carriage section 11 has a guide rail parallel to the magnetic scale rod in the frame 10, and has a structure in which the head holding section 12 holding the detection head slides on the guide rail.

When the detection head detects the magnetic scale from the magnetic scale rod, it outputs a detection signal to the outside through the output cable 13.

[0005]

The problem to be solved is that in the linear scale having the above-described structure, the detection head moves with respect to the magnetic scale rod. The output cable 13 also moves. Therefore, when the linear scale is mounted on a machine tool or the like, a space corresponding to the moving range of the output cable 13 is required.

Further, when the output cable 13 is put out of the frame 10, it moves together with the detection head.
There is a problem in that the output cable 13 is likely to be damaged due to increased contact with members of an external device such as a machine tool. In order to solve this problem, the applicant of the present invention provided a flexible output cable for outputting a detection signal of a detection head in a scale frame in a linear scale in which the detection head is moved with respect to the scale. The flexible output cable moves according to the moving range of the detection head. A guide plate made of a flat metal thin plate is provided along the flexible cable to protect the flexible output cable (Japanese Utility Model Application Laid-Open No. 60-1998).
Suggested.

With such a configuration, when the linear scale body is mounted on a machine tool or the like, a space corresponding to the moving range of the flexible output cable can be omitted, and the flexible output cable is greatly damaged. Can be prevented. However, when the linear scale body is long (for example, 1 m or longer), the flexible output cable is loosened from the guide plate and the flexible output cable due to rapid movement of the detection head, and moves separately. In addition, a phenomenon occurs in which smooth follow-up in the scale frame cannot be performed, and as a result, there is a problem that the flexible output cable is bent to cause disconnection. The purpose of the present invention is to solve the above problems.

[0008]

According to the present invention, as shown in FIGS. 1 and 2, a scale on which a predetermined scale pattern is recorded and a frame for supporting and fixing both ends of the scale are provided. A body, a detection head that moves relative to the scale and detects a scale pattern, carriage means provided with a guide parallel to the scale, and slides the guide to move the detection head; and the carriage means A flexible output cable that is accommodated in the frame with a movement range of the detection head moved by the sensor and transmits a detection signal of the detection head, and is disposed at one end in the movement direction of the detection head within the frame. In a linear scale comprising an external output connector to which the flexible output cable is connected, a connector is provided along the outer surface of the flexible output cable. Beck-shaped metallic tape disposed, linear scale adhered and a flexible output cable and convex shaped metallic tape.

[0009]

In the above construction, the detection head moves in accordance with the sliding of the carriage portion, and the flexible output cable also moves with the movement of the detection head, but a convex metal tape is provided along the outer surface thereof. Therefore, the flexible output cable smoothly moves while maintaining a constant shape curved so that the upper and lower sides are substantially parallel.

[0010]

FIG. 1 is a front sectional view showing an entire structure of an embodiment of the present invention. In FIG. 1, the magnetic scale rod 1 has a magnetic scale pattern recorded at equal intervals on its surface in advance, and both ends are supported and fixed in a frame 10 respectively. The detection head 2 is held and fixed to the carriage unit 11, and is configured to move along the magnetic scale rod 1 by sliding of the carriage unit 11. In this case, the detection head 2 is a head having a structure corresponding to, for example, the coaxial magnetic scale rod 1 as shown in FIG.

The magnetic scale detected by the detection head 2 is converted into an electric signal and then output through a flexible output cable 3. The flexible output cable 3 is a flat cable, one end of which is attached to the carriage 11 and the other end of which is connected to the amplifier 4. In such a connection state, the flexible output cable 3 is housed in the frame body 10 in a state of being bent in a curved shape so as to move flexibly over the range of movement of the detection head 2.

Here, the flexible output cable 3 is specifically attached to the carriage section 11 as shown in FIG. That is, the distal end of the flexible output cable 3 is connected to the connection board 5, and is connected to the output line 6 of the detection head 2 via the connection board 5. Further, a convex-shaped metal tape 7 having a U-shaped cross section is disposed on the outer surface of the flexible output cable 3 and the flexible output cable 3 and the convex-shaped metal tape 7 are epoxy-bonded. Adhering as appropriate with an elastic adhesive such as a system. In consideration of the function of protecting and guiding the flexible output cable 3 and the flexibility of the flexible output cable 3, it is desirable that the bonding be made at equal intervals.

The convex-shaped metal tape 7 having a U-shaped cross section is used, for example, for a tape measure. One of the tapes has a concave surface and the other has a convex surface. Even if it is bent, it can maintain a predetermined shape in the longitudinal direction.

The amplification section 4 amplifies the detection signal transmitted through the flexible output cable 3 and outputs the amplified signal to the external output connector 8. An external output line 9 is connected to the external output connector 8, and a detection signal from the amplifying unit 4 is supplied to an external device such as a machine tool through the external output line 9.

The carriage section 11 has a structure in which it slides on a guide rail 14 arranged in parallel with the magnetic scale rod 1 using a bearing 15 as shown in FIG. 3A, for example. Become. The sliding of the carriage unit 11 causes the detection head 2 to move along the magnetic scale rod 1. FIG. 3B is a partial side sectional view with respect to FIG.

The operation of one embodiment of the linear scale having the above configuration will be described. Now, it is assumed that the carriage 11 slides on the guide rail 14 and moves parallel to the magnetic scale rod 1. At this time, a handle 16 which is usually installed outside the frame 10 is attached to the carriage portion 11 as shown in FIG. 3A, and the carriage portion 11 is slid by operating the handle 16. Will move. As the carriage 11 slides, the detection head 2 moves along the magnetic scale rod 1 and detects the magnetic scale recorded on the magnetic scale rod 1. The detection head 2 converts the detected magnetic scale into an electric signal, and outputs the electric signal to the flexible output cable 3.

At this time, the flexible output cable 3 is bent and accommodated in the frame 10 so that the upper and lower portions thereof are substantially parallel to each other along the convex-shaped metal tape 7 so that the shape is always maintained. Is configured. The detection signal from the detection head 2 is transmitted through the flexible output cable 3 and sent to the amplifier 4, amplified by the amplifier 4, and then output to the external output connector 8. Then, a detection signal from the detection head 2 is output to an external device through an external output line 9 connected to the external output connector 8. Based on this detection signal, the displacement (movement amount) of the detection head 2 is detected.

By the way, the detection head 2 is
When moving in accordance with the sliding of 1, the flexible output cable 3 attached to the carriage unit 11 also moves. The flexible output cable 3 is a flexible flat cable as described above, and the frame 1
0, and is adhered along the convex-shaped metal tape 7 located outside.
The detection head 2 moves smoothly in accordance with the movement of the detection head 2 while maintaining a fixed shape curved so that the upper and lower sides are substantially parallel. Therefore, the flexible output cable 3 is the frame 1 of the linear scale.
Since it moves smoothly within a predetermined range within 0, it does not come into contact with members of the external device. Further, the flexible output cable 3 does not directly contact the frame 10 in the frame 10.

For this reason, the flexible output cable 3 is damaged by contact with members of the external device and the frame 10
Disconnection due to unnecessary bending in the inside can be prevented. Also, damage due to friction with the frame 10 can be prevented. Thus, the life of the flexible output cable 3 can be extended, and the detection signal of the detection head 2 can be output stably at all times.

In the above embodiment, the case of the magnetic linear scale has been described. However, the present invention is not limited to this and can be applied to the case of an optical linear scale. This optical linear scale normally has a scale pattern recorded on a glass substrate 40 as shown in FIG. 4A, and the photoelectric sensor 41 moves with respect to the glass substrate 40. The photoelectric sensor 41 includes, for example, a light emitting diode 42 and a light receiving diode 43 as shown in FIG.
And the diodes 42 and 43 are held by the support frame 44 so as to face the glass substrate 40 up and down, respectively. Even in the case of such an optical linear scale, the photoelectric sensor 41 moves. Therefore, by using the above-described flexible output cable 3 and the convex-shaped metal tape 7, the same as in the embodiment of the magnetic scale is achieved. Effects can be obtained.

[0021]

The present invention is constructed as described above. Therefore, in a magnetic linear scale or an optical linear scale of a detection head movable type, a flexible output for moving according to the movement of the detection head is provided. The cable can always be kept in a constant shape and smoothly moved. Therefore, unnecessary bending of the output cable in the frame of the scale can be prevented, so that the flexible output cable can be prevented from being bent or unnaturally bent, and the flexible output cable can be prevented from being broken or damaged. Measurement can be performed, and damage due to contact between the flexible output cable and the frame can be prevented, so that the life of the flexible output cable can be extended.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing a configuration of a magnetic linear scale according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a partial configuration of FIG. 1;

3A is a front sectional view and FIG. 3B is a partial side sectional view showing a specific example of a partial configuration of the linear scale of FIG.

4A and 4B are perspective views showing a partial configuration of an optical linear scale according to another embodiment of the present invention, and FIG.

FIG. 5 is a perspective view showing the appearance of a conventional magnetic linear scale.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Magnetic scale rod, 2 ... Detection head, 3 ... Flexible output cable, 4 ... Amplifier part, 5 ... Connection board, 6 ... Output wire, 7 ... Convex-shaped metal tape, 8 ... External output connector , 9: external output line, 10: frame, 11: carriage, 14: guide rail, 15: bearing, 16
… Toride.

Claims (1)

(57) [Scope of request for utility model registration] 1. A scale on which a predetermined scale pattern is recorded, a frame supporting and fixing both ends of the scale, a detection head which moves relatively to the scale and detects the scale pattern, and the scale A carriage means for moving the detection head by sliding the guide, and a detection signal of the detection head housed in the frame body with a moving range of the detection head moved by the carriage means. A linear scale comprising: a flexible output cable to be transmitted; and an external output connector disposed at one end of the detection body in the moving direction of the detection head in the frame and connected to the flexible output cable. A convex-shaped metal tape is disposed along the outer surface of the flexible output cable, and the flexible output cable and the convex-shaped metal tape are disposed. A linear scale that is bonded to a metal tape.