Wear detection method and wear detection system for linear actuator

Patent metadata

Field	Value
Publication number	US-11402297-B2
Application number	US-201816223192-A
Country	US
Kind code	B2
Filing date	Dec 18, 2018
Priority date	Dec 27, 2017
Publication date	Aug 2, 2022
Grant date	Aug 2, 2022

Abstract

A wear detection method and system for a linear actuator such as a pneumatic cylinder, a hydraulic cylinder, an electric cylinder or the like. A physical amount detection sensor 9 is mounted on a linear actuator in which a push-pull member connected to a rod 2 pushes and pulls a pressure-receiving object while applying a lateral load in a direction different from the linear movement direction. An external force that is generated between a tube and the mounting member when the pressure-receiving object is pushed and pulled is detected by the physical amount detection sensor 9 and compared with standard external force data, which was detected in a state without abnormalities and stored in a computation/storage/determination processing device 10, to computationally determine whether the linear actuator is in a normal state or an abnormal state.

First claim

The invention claimed is:

1. A wear detection method for a linear actuator that comprises a rod capable of moving linearly inside a tube mounted on a mounting member, and that pushes and pulls a pressure-receiving object while a push-pull member connected to the rod applies a lateral load in a direction different from a linear movement direction, the wear detection method comprising:
a storage step of pre-detecting, with a physical amount detection sensor, a first external force generated between the mounting member and the tube when the pressure-receiving object is pushed and pulled in a state without abnormalities, and storing the first external force, as standard external force data, in a computation/storage/determination processing device; and
a determination step of detecting, with the physical amount detection sensor, a second external force generated between the mounting member and the tube when the pressure-receiving object is pushed and pulled, and computationally determining whether the linear actuator is in a normal state or an abnormal state by comparing the second external force with the standard external force data stored in the computation/storage/determination processing device.

2. The wear detection method for the linear actuator according to claim 1 , wherein a force sensor is used as the physical amount detection sensor.

3. The wear detection method for the linear actuator according to claim 2 , wherein, during the determination step, an average value of external force data for an immediately preceding plurality of steps is compared with the second external force, and the linear actuator is also determined as being in the abnormal state when the second external force is outside a preset tolerance range with respect to the average value.

4. The wear detection method for the linear actuator according to claim 1 , wherein, during the determination step, an average value of external force data for an immediately preceding plurality of steps is compared with the second external force, and the linear actuator is also determined as being in an abnormal state when the second external force is outside a preset tolerance range with respect to the average value.

5. A wear detection system for a linear actuator that comprises a rod capable of moving linearly inside a tube mounted on a mounting member, and that pushes and pulls a pressure-receiving object while a push-pull member connected to the rod applies a lateral load in a direction different from a linear movement direction, the wear detection system comprising:
a physical amount detection sensor that detects a first external force generated between the mounting member and the tube when the pressure-receiving object is pushed and pulled; and
a computation/storage/determination processing device that stores, as standard external force data, a second external force detected by the physical amount detection sensor in a state without abnormalities, and that computationally determines whether the linear actuator is in a normal state or an abnormal state by comparing, with the standard external force data, the first external force detected in the physical amount detection sensor when the pressure-receiving object is pushed and pulled.

6. The wear detection system for the linear actuator according to claim 5 , wherein the physical amount detection sensor is a force sensor.

7. The wear detection system for the linear actuator according to claim 6 , wherein the linear actuator is a pneumatic cylinder, a hydraulic cylinder or an electric cylinder.

8. The wear detection system for the linear actuator according to claim 5 , wherein the linear actuator is a pneumatic cylinder, a hydraulic cylinder or an electric cylinder.

Assignees

• Sintokogio Ltd

Inventors

• Nagasaka Masahiko
• Makino Hiroyasu
• Odagi Katsuaki
• Yokomae Tomoyuki

Classifications

• F15B19/005

  Fault detection or monitoring · CPC title

• F16H21/40

  for interconverting rotary motion and oscillating motion · CPC title

• F15B2211/6303

  using input signals · CPC title

• F15B2211/6336

  representing a state of the output member, e.g. position, speed or acceleration · CPC title

• F15B15/20 Primary

  Other details {, e.g. assembly with regulating devices} · CPC title