JPH057523Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention is a magnetic linear scale that magnetically detects the position and length of a straight line in various devices such as printers, NC machines, floppy disks, and robots. Regarding.

[Conventional technology]

A magnetic linear scale measures position and length by moving a magnetic sensor made of a magnetoresistive element over a magnetic recording medium whose magnetic poles are magnetized in opposite directions alternately at regular intervals to convert changes in magnetic flux into electrical signals. An example of this is shown in Utility Model Application No. 110106/1983, for example. In this magnetic linear scale, it is necessary to keep the gap between the magnetized magnetic recording medium and the magnetic sensor constant. Therefore, in order to maintain the gap without contact, the parts used and the finished dimensional accuracy during assembly are required to be high, which inevitably leads to high costs. On the other hand, the third
As shown in the figure, a magnetic sensor 1 is bonded to a recess formed on the lower surface side of a guide holder 2 driven by a movable part (not shown), and a ferromagnetic wire 3 as a magnetic recording medium is connected to the magnetic sensor 1. This is to maintain the gap between them. It goes without saying that the ferromagnetic wires 3 are magnetized alternately in opposite directions at predetermined pitches. Reference numeral 11 denotes a detection signal extraction line.

[Problem that the invention attempts to solve]

In the example shown in FIG. 3, the guide holder 2 contacts the ferromagnetic wire 3, and the magnetic sensor 1 and the ferromagnetic wire 3 move without contact, but the gap between the magnetic sensor 1 and the ferromagnetic wire 3 is Variations occur in the dimensional accuracy of the recess to which the magnetic sensor 1 is fixed, the thickness of the adhesive layer, the thickness of the magnetic sensor, etc.

An object of the present invention is to provide a magnetic linear scale that can set the gap between a magnetic sensor and a magnetic recording medium to a constant value with a simple structure using a contact method.

[Means for solving problems]

The present invention includes a magnetic recording medium made of a magnetic metal with high coercive force that is magnetized in opposite directions alternately at a constant magnetic pole interval, and a magnetic sensor attached to a movable part that can move along the longitudinal direction of the magnetic recording medium. In the magnetic linear scale, a cantilevered leaf spring is provided in the movable part, and a gimbal having an axis of freedom in a direction perpendicular to the longitudinal direction of the magnetic recording medium is provided on the tip side of the leaf spring. The gimbal is characterized in that the gimbal grips the magnetic sensor so that a portion of the gimbal is interposed between the magnetic sensor and the magnetic recording medium.

〔Example〕

An embodiment of the present invention is shown in FIGS. 1 and 2. The magnetic sensor 1 uses a magnetic resistance element. The ferromagnetic wire 3 consists of metal magnetic wires that are alternately magnetized in opposite directions at constant magnetic pole intervals. One end of a plate spring support 4 is fixed to the movable part 5 of the object to be detected to form a cantilever spring. A gimbal 42 is constructed on the distal end side of the support body 4 at a position facing the ferromagnetic wire 3 and is constructed by thin spring plates 41 on both edges. Furthermore, both ends of the gimbal 42 are bent downward to enclose the magnetic sensor 1 on the lower surface side. A part of the bent portion 43 is connected to the magnetic sensor 1
and the ferromagnetic wire 3 to determine the gap size between them.

Due to the spring pressure of the support body 4 and the gimbal support structure, it is possible to stably follow the undulations of the ferromagnetic wire 3, and the magnetic sensor 1
The gap between the ferromagnetic wire 3 and the ferromagnetic wire 3 can also be kept constant.

The support 4 has spring properties as well as abrasion resistance.
Slidability is also required, but stainless steel spring material with a thickness of about 0.03 to 0.1 mm is used, and if necessary, wear-resistant coatings are applied to the parts that come into contact with the ferromagnetic wire.

[Effect of idea]

As described above, according to the present invention, the gap between the magnetic sensor and the magnetic recording medium can be kept constant with a simple structure, and a magnetic linear scale with stable output can be provided.

[Brief description of the drawings]

Figure 1 is a view from above of the main parts of the magnetic linear scale according to the present invention, and Figure 2 is an arrow A in Figure 1.
-A view seen from the A direction, FIG. 3 is a schematic diagram of an example of a conventional magnetic linear scale. 1...Magnetic sensor, 2...Guide holder, 3...
...Ferromagnetic wire, 4...Support, 5...Movable part,
41...Spring plate, 42...Gimbal.

Claims (1)

[Scope of utility model registration request] A magnetic type having a magnetic recording medium made of a magnetic metal with high coercive force that is magnetized alternately in opposite directions at constant magnetic pole intervals, and a magnetic sensor attached to a movable part that can move along the longitudinal direction of the magnetic recording medium. In the linear scale, a cantilevered leaf spring is provided in the movable part so as to cross the magnetic recording medium at intervals, and the tip side of the leaf spring has an axis of freedom in the extending direction of the leaf spring. 1. A magnetic linear scale comprising: a gimbal having a gimbal; the gimbal grips the magnetic sensor so that a part of the gimbal is interposed between the magnetic sensor and the magnetic recording medium.