SLEWING-TYPE WORKING MACHINE

• US 20130307443A1
• Filed: 12/28/2011
• Published: 11/21/2013
• Est. Priority Date: 02/02/2011
• Status: Active Grant

• Current Assignee: Kobelco Construction Machinery Company Limited (Kobe Steel Limited)
• Original Assignee: Kobelco Construction Machinery Company Limited (Kobe Steel Limited)
• Inventors: Hirozawa, Mitsunori
• Granted Patent: US 9,077,272 B2
• Time in Patent Office: Days
• US Class Current: 318/139
• CPC Class Codes: B60L 1/003 to auxiliary motors, e.g. for pumps, compressors
• CPC Class Codes: B60L 1/20 Energy regeneration from auxiliary equipment
• CPC Class Codes: B60L 2200/42 Fork lift trucks
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/80 Time limits
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 58/13 Maintaining the SoC within a determined range
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: B60L 7/10 Dynamic electric regenerative braking B60L7/22 takes precedence
• CPC Class Codes: E02F 9/128 Braking systems
• CPC Class Codes: E02F 9/2091 Control of energy storage means for electrical energy, e.g. battery or capacitors energy recovery arrangements in hydraulic or pneumatic drives E02F9/2217
• CPC Class Codes: E02F 9/2095 Control of electric, electro-mechanical or mechanical equipment not otherwise provided for, e.g. ventilators, electro-driven fans control of hydraulic driven equipment E02F9/22
• CPC Class Codes: E02F 9/268 with failure correction follow-up actions
• CPC Class Codes: H02P 27/00 Arrangements or methods for the control of AC motors characterised by the kind of supply voltage of two or more motors H02P5/00; of synchronous motors with electronic commutators H02P6/00; of DC motors H02P7/00; of stepping motors H02P8/00
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/92 Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles

Abstract

A slewing-type working machine includes: an electric storage device capable of being charged with regenerative electric power for regenerating slewing energy of an upper slewing body while functioning as an electric power source for an electric slewing motor; an electric storage device and electric storage device controller detecting whether the electric storage device is under a normal condition with sufficient capacity to regenerate the slewing energy or under an abnormal condition without sufficient capacity; and a controller controlling a velocity of the electric slewing motor based on a result of detection by the electric storage device and electric storage device controller, wherein the controller performs a velocity limiting control for limiting a maximum velocity of the electric slewing motor when the electric storage device is under the abnormal condition.

Claims

1. A slewing-type working machine comprising:

a lower propelling body;

a upper slewing body rotatably provided on the lower propelling body;

an electric slewing motor causing the upper slewing body to slew, and generating regenerative braking force and regenerative electric power during slewing braking of the upper slewing body;

a electric storage device functioning as an electric power source for the electric slewing motor, and capable of being charged with the regenerative electric power to regenerate slewing energy of the upper slewing body;

electric storage device condition detecting means detecting whether the electric storage device is under a normal condition with sufficient capacity to regenerate the slewing energy or under an abnormal condition without sufficient capacity; and

control means controlling a velocity of the electric slewing motor based on a result of detection by the electric storage device condition detecting means, wherein

the control means performs a velocity limiting control for limiting a maximum velocity of the electric slewing motor when the electric storage device is under the abnormal condition.

2. The slewing-type working machine according to claim 1, wherein

the electric storage device condition detecting means has charge level detecting means detecting a charge level of the electric storage device;

and

the control means determines that the electric storage device is under the abnormal condition when the charge level detected by the charge level detecting means is equal to or more than a preset charge level value and performs the velocity limiting control.

3. The slewing-type working machine according to claim 1, wherein

the electric storage device condition detecting means has capacity detecting means detecting a capacity of the electric storage device;

and

the control means determines that the electric storage device is under the abnormal condition when the capacity of the electric storage device detected by the capacity detecting means is equal to or less than a preset capacity value and performs the velocity limiting control of the electric slewing motor.

4. The slewing-type working machine according to claim 3, wherein the capacity detecting means detects a temperature of the electric storage device and determines the capacity of the electric storage device based on the detected temperature.

5. The slewing-type working machine according to claim 4, wherein the capacity detecting means has a temperature detecting section detecting the temperature of the electric storage device and a capacity determining section which stores in advance capacity information indicative of a relationship between the temperature of the electric storage device and the capacity of the electric storage device and which determines the capacity of the electric storage device based on the temperature of the electric storage device detected by the temperature detecting section and the capacity information.

6. The slewing-type working machine according to claim 1, further comprising moment-of-inertia detecting means detecting a moment of inertia of a working attachment fitted on the upper slewing body, wherein

the control means performs the velocity limiting control when the electric storage device is under the abnormal condition and when the moment of inertia of the working attachment detected by the moment-of-inertia detecting means is equal to or more than a preset value.

7. The slewing-type working machine according to claim 1, wherein the electric storage device condition detecting means starts detecting whether or not the electric storage device is under the normal condition or the abnormal condition after lapse of a predetermined time period from start of a slewing operation.

8. The slewing-type working machine according to claim 1, further comprising a slewing operating section outputting a velocity command to the electric slewing motor, wherein

the control means sets a velocity gain to an amount of operation such that the velocity of the electric slewing motor varies continuously in accordance with the amount of operation of the slewing operating section over an entire operation range of the slewing operation section while the velocity of the electric slewing motor at a maximum amount of operation of the slewing operating section reaches the limited maximum velocity.