JPH0413680Y2 - - Google Patents

Description

[Detailed description of the invention] (1) Field of industrial application This invention is used for track access of recording and reproducing heads of magnetic disks and optical disk devices, and for linear positioning tables that move in a straight line. The present invention relates to a linear slide table.

(2) Prior art Figure 2 shows a conventional linear positioning table, in which 1 is a bed, 2 is a table,
3 and 3' are rails, 4' is a linear scale, and 5' is a sensor section. The linear slide table has rails 3, 3' built into the guide portions of the table 1 and bed 2, and is capable of linear movement.
However, in order to use this as a positioning table, a sensor for detecting the position is required.As shown in the figure, the linear scale 4' is fixed and the position is detected by the sensor 5' attached to the table 2. is possible. The linear positioning table requires the linear scale 4' and the sensor 5' externally in addition to the linear slide table, so the device becomes large in size. Accuracy adjustment becomes difficult, and since the lead wire coming out of the sensor unit moves with the table, there is a high risk of it breaking and positioning becoming impossible.Furthermore, when using a magnetic scale sensor, it is exposed to the outside. Therefore, there were problems such as being susceptible to the influence of external magnetic fields from motors etc., which could cause malfunctions.

(3) Purpose of the invention The purpose of the invention is to solve the above-mentioned problems with the conventional technology by incorporating a magnetic linear scale into the table that constitutes the linear slide table, and by incorporating a magnetic sensor into the bed. The purpose of the present invention is to provide a highly effective, compact, highly accurate, and low-cost linear slide table with an encoder.

(4) Structure of the invention The present invention is a linear slide table that incorporates rails 3 and 3' into the guide parts of the table 2 and bed 1 to perform linear motion. having regions magnetized at intervals,
At least one wire or shaft-shaped linear scale 4 made of a magnetic material with high coercive force is installed in parallel to the stroke direction, and a magnetic sensor 5 using a magnetoresistive element is installed in the bed 1 to prevent the movement of the table 2. This is a linear slide table with an encoder built in so as to always maintain a constant distance from the scale 4.

(5) Function The linear slide table magnetically shields the linear scale and magnetic sensor.

(6) Examples Examples of the present invention will be described below with reference to the drawings.
FIG. 1a is a sectional view of a linear slide table with an encoder according to the present invention. In the figure, 1 is a bed, 2 is a table, 3 and 3' are rails, 4 is a magnetic linear scale, 5 is a magnetic sensor, and 6 and 6' are driving linear motors.

In the figure, rails 3 and 3' are incorporated in the guide portions of the table 2 and the bed 1, respectively, and are capable of linear movement with a runout accuracy of several μm.

The table 2 is equipped with a magnetic scale 4 made of a magnetic material having a high coercive force, which is magnetized at equal intervals with the direction of the magnetic poles reversed in the longitudinal direction as shown in Fig. 1b. A magnetic sensor 5 using a magnetoresistive element is installed in the bed 1 at a location that does not interfere with the movement of the table 2 while always maintaining a constant distance from the linear scale 4.
It is possible to detect the magnetized state of the scale 4. In order to drive the table, linear motors 6 and 6' are connected to each other from both sides of the table, and by energizing the linear motors 6 and 6', the table can be moved back and forth.

Scale 4 inside iron tables and beds
By incorporating the scale 4 and sensor 5, it serves as a magnetic shield, and has the effect of preventing malfunctions caused by external magnetic fields emitted from motors, etc., which are common with magnetic sensors. The high accuracy has the effect of increasing the quality of the output signal from the sensor.

Furthermore, the sensor section is housed inside the table, which has the effect of making it more compact.

(7) Effects of the invention As described above, in the linear slide table with encoder according to the invention, the magnetic linear scale and magnetic sensor are incorporated inside the linear slide table, which has a magnetic shielding effect against external magnetic fields. In addition, the high gap accuracy between the scale and sensor improves the quality of the sensor output signal, and the sensor unit is housed inside the table, making it more compact. The industrial value of this invention is great.

[Brief explanation of the drawing]

FIG. 1 shows a linear slide table according to the present invention. A is a sectional view, b is a magnetic linear scale, and c is a perspective view of a table. FIG. 2 is a perspective view of a conventional linear positioning table. In the figure, 1...bed, 2...table,
3, 3'...Rail, 4, 4'...Linear scale, 5, 5'...Sensor, 6, 6'...Driving linear motor.

Claims (1)

[Scope of utility model registration request] A linear slide table that incorporates a rail into the guide section of the table and bed to perform linear motion.
On the table part, the direction of the magnetic poles is alternately reversed,
At least one wire or shaft-shaped linear scale made of a magnetic material with high coercive force and magnetized regions at equal intervals is incorporated in parallel to the stroke direction, and the bed portion has a magnetoresistive effect element. The sensor is installed at a location that does not impede movement of the table so as to always maintain a constant distance from the scale.
Linear slide table with encoder.