JPH0712912U - Direct acting position sensor - Google Patents

Abstract

(57) [Summary] [Purpose] The objective is to reduce wear of the rod tip of the direct-acting position sensor and the contact portion of the detected object. [Structure] The rod 3 of a direct-acting position sensor 1 having a rod 3 that moves according to the movement of an object 17 to be detected.
A resin material 20 having a low coefficient of friction is attached to the tip of the, and the object to be detected 17 is brought into contact with the resin material 20 through the resin material 20.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of a direct-acting position sensor for detecting the movement amount and position of an object to be detected.

[0002]

[Prior art and its problems]

 2. Description of the Related Art Conventionally, a direct-acting position sensor has a structure as shown in FIG. 2 as an external perspective view and as shown in FIG. 3 as a sectional configuration view, and is used, for example, in a mode as shown in FIG. That is, the position sensor 1 is provided with a rod 3 protruding from the case 2, a flange portion 4 having a bolt hole 5 is formed on a side surface of the case 2, and a bolt 6 is inserted into the bolt hole 5. Be attached to the device.

The rod 3 can be moved in a direction in which the rod 3 is retracted from the case 2 via a bearing 7 in the case 2, and a brush holder 8 is attached to an inner end portion of the rod 3. The brush holder 8 is provided with a brush 9. A spring 10 is attached to the end of the brush holder 8, and the rod 3 is always urged outward by the spring 10.

The brush 9 is in contact with a resistance substrate 11 arranged in the case 2, and a lead wire 12 is connected to the resistance substrate 11. When the brush 9 comes into contact with the resistance substrate 11 and moves on the resistance substrate 11 by the movement of the rod 3, the resistance value changes, the voltage signal output from the lead wire 12 changes, and the movement amount of the rod 3 changes. And the position is to be detected.

The position sensor 1 as described above is fixedly mounted in a case 15 through bolts 6 in FIG. 4, and a fixed shaft 16 having a male screw 16a formed on the outer periphery is fixedly fixed in the case 15. A gear 17 is screwed onto the fixed shaft 16. The gear 17 is meshed with a gear 19 fixed to the motor shaft of the motor 18. The rod 3 of the position sensor 1 is in contact with the back surface of the gear 17, and when the gear 17 moves on the fixed shaft 16 by the rotation of the motor 18, the rod 3 is moved in accordance with this movement and the gear 17 moves. The movement amount and movement position can be detected by the position sensor 1.

In such a conventional structure, since the tip of the rod 3 comes into contact with the gear 17 which is the object to be detected, there is a problem that the contact portion between the tip of the rod 3 and the gear 17 is abnormally worn.

[0007]

[Means for Solving the Problems]

 The present invention has been made in view of the above conventional problems, and an object thereof is not to provide a direct-acting position sensor that can reduce friction and wear of a contact portion between a rod and an object to be detected. The gist is that a brush is attached to a rod that is displaced according to the movement of the detected object, the brush is brought into contact with the resistance substrate, and the resistance value is changed according to the movement of the detected object. In a direct-acting position sensor that outputs a voltage signal according to the amount of movement, a resin material having a low friction coefficient is attached to the tip of the rod that comes into contact with the object to be detected.

[0008]

[Action]

 A resin material with a low friction coefficient is attached to the tip of the rod of the direct-acting position sensor, and it comes into contact with the object to be detected. Mutual wear is suppressed, and a direct-acting position sensor with great durability can be obtained.

[0009]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a main part in a state where the direct-acting position sensor is mounted in the apparatus shown in FIG. 4, and the direct-acting position sensor 1 is fixed to a case 15 via bolts 6. A resin material 20 having a low coefficient of friction, preferably having a coefficient of friction of 0.3 or less, is fixedly attached to the tip of the rod 3, and the rod 3 is connected via the resin material 20 to a gear 17 which is an object to be detected. It is in sliding contact with the back surface 17a. As a material of such a resin material 20, there is, for example, a polyimide resin.

On the other hand, a ring-shaped protrusion 21 is integrally formed on the back surface 17a of the gear 17, which is the object to be detected. The projection 21 has a substantially L-shaped cross section in which the tip portion 21a is bent outward in the radial direction, and the resin material 20 at the tip of the rod 3 is partially interposed between the tip portion 21a and the back surface 17a of the gear 17. Is formed with an annular groove 22 for receiving. The tip portion 21a faces the resin material 20 in the axial direction with a slight gap.

When the motor 18 in FIG. 4 rotates, the gear 17 rotates via the gear 19, and the gear 17 moves on the fixed shaft 16 with rotation. At this time, the rod 3 moves by following the axial movement of the gear 17 while maintaining the contact state with the back surface 17a of the rotating gear 17 by the urging force of the spring 10. The contact between the rod 3 and the back surface 17a of the gear 17 is performed through the resin material 20 with a low frictional resistance, and the contact surface between the rod tip and the gear 17 is abnormally worn as in the conventional case. There is no.

Further, the resin material 20 at the tip of the rod 3 is partially received in the annular groove 22 formed by the projection 21 of the gear 17, and this receiving state is maintained regardless of the rotation of the gear 17. Therefore, for example, even if the follow-up movement of the rod 3 when the gear 17 moves in the direction away from the position sensor 1 has a problem, the tip end 21a of the projection 21 catches the resin material 20 and the rod 3 moves. It is possible to reliably move the.

[0013]

[Effect of device]

 According to the present invention, a brush is attached to a rod that is displaced according to the movement of an object to be detected, the brush is brought into contact with a resistance substrate, and the resistance value is changed in accordance with the movement of the object to be detected. In a direct-acting position sensor that outputs a voltage signal according to the above, the rod with a low friction coefficient is attached by attaching a resin material with a low friction coefficient to the tip of the rod that contacts the object to be detected. Since it comes into contact with the object to be detected through the contact, even if the object to be detected is accompanied by rotational movement, mutual wear of the contact parts is suppressed, and a direct-acting position sensor with great durability can be obtained. Have an effect.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a main part in a state where a direct-acting position sensor of the present invention is assembled to an object to be detected.

FIG. 2 is an external perspective view of a conventional direct-acting position sensor.

FIG. 3 is an internal structure diagram of a conventional direct-acting position sensor.

FIG. 4 is a schematic configuration diagram of an apparatus in which a direct-acting position sensor is assembled.

[Explanation of symbols]

 1 Direct Acting Type Position Sensor 2 Case 3 Rod 9 Brush 11 Resistance Board 17 Gear (Detection Object) 20 Resin Material

Claims (1)

[Scope of utility model registration request] 1. A brush is attached to a rod which is displaced according to the movement of an object to be detected, and the brush is brought into contact with a resistance substrate,
In a direct-acting position sensor that outputs a voltage signal according to the amount of movement by changing the resistance value in response to the movement of the object to be detected, the tip of the rod in contact with the object to be detected has a friction coefficient of A direct-acting position sensor featuring a low resin material.