STROKE DETECTOR

• US 20180136014A1
• Filed: 11/24/2015
• Published: 05/17/2018
• Est. Priority Date: 12/05/2014
• Status: Abandoned Application

• Current Assignee: KYB Corp.
• Original Assignee: KYB Corp.
• Inventors: SUGIHARA, Katsumichi
• Application Number:
  US15/531,943
• Publication Number:
  US 20180136014A1
• Time in Patent Office: Days
• CPC Class Codes: F15B 15/2846 using detection of markings, e.g. markings on the piston rod
• CPC Class Codes: F15B 15/2861 using magnetic means
• CPC Class Codes: F15B 2211/7051 Linear output members
• CPC Class Codes: G01B 7/00 Measuring arrangements characterised by the use of electric or magnetic techniques
• CPC Class Codes: G01B 7/003 for measuring position, not involving coordinate determination coordinate measuring G01B7/004
• CPC Class Codes: G01D 2205/77 Specific profiles
• CPC Class Codes: G01D 5/145 influenced by the relative movement between the Hall device and magnetic fields see G01R33/06
• CPC Class Codes: G01D 5/147 influenced by the movement of a third element, the position of Hall device and the source of magnetic field being fixed in respect to each other
• CPC Class Codes: G01D 5/24438 Special design of the sensing element or scale
• CPC Class Codes: G01D 5/24476 Signal processing G01D5/2448 - G01D5/24495 take precedence

Abstract

A stroke detector includes: a cylinder tube; a piston rod configured to advance and retract with respect to the cylinder tube; a scale that is formed on the piston rod; and a first MR sensor and a second MR sensor that are provided on the cylinder tube. The scale has a first edge portion that is opposed to the first MR sensor and a second edge portion that extends at a different angle from that of the first edge portion and that is opposed to the second MR sensor.

Claims

1. A stroke detector comprising:

a first member;

a columnar second member configured to advance and retract with respect to the first member;

a scale that is formed on a surface of the second member along an advancing/retracting direction of the second member; and

a first detecting element and a second detecting element that are provided on the first member so as to oppose to the scale, the first detecting element and the second detecting element being configured to change outputs therefrom in accordance with opposing area of the scale;

wherein

the scale has a first edge portion that is inclined with respect to the advancing/retracting direction of the second member and a second edge portion that extends at a different angle from that of the first edge portion with respect to the advancing/retracting direction of the second member,

the first edge portion is formed so as to always oppose to the first detecting element within an advancing/retracting range of the second member, and the second edge portion is formed so as to always oppose to the second detecting element within the advancing/retracting range of the second member,

the advancing/retracting direction of the second member in which the area of the scale opposing to the first detecting element is gradually increased and the advancing/retracting direction of the second member in which the area of the scale opposing to the second detecting element is gradually increased are opposite directions,

the scale has a first scale having the first edge portion and a second scale having the second edge portion,

the first scale and the second scale are provided within a range of less than 90 degrees in a circumferential direction of the second member, and

a stroke of the second member is detected on the basis of difference between output from the first detecting element and output from the second detecting element.

2. The stroke detector according to claim 1, wherein

a position of the first edge portion on the first scale and a position of the second edge portion on the second scale are respectively set such that, when the second member is displaced with respect to the first member in the circumferential direction, a direction of change in the output from the first detecting element becomes same as a direction of change in the output from the second detecting element.

3. The stroke detector according to claim 2, wherein the first scale and the second scale are respectively formed to have a rectangular shape.

4. (canceled)

5. (canceled)

6. (canceled)

7. (canceled)