JP2008080851A - Suspension device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a suspension device capable of obtaining damping force to meet the laden weight of a vehicle. <P>SOLUTION: The suspension device comprises an air spring 3 between a sprung mass corresponding member 1 and an unsprung mass corresponding member 2, an electromagnetic shock absorber 4 which connects the sprung mass corresponding member 1 to the unsprung mass corresponding member 2 and increases/decreases the damping force according to the resistance, a sensor 5 for detecting the internal pressure of the air spring 3, and a controller 8 which calculates the laden weight of a vehicle based on information from the sensor 5 and adjusts the resistance so that the corresponding damping force can be provided by the electromagnetic shock absorber 4. The damping force of the electromagnetic shock absorber 4 is adjusted in a continuously variable manner according to the laden weight. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a suspension device suitable for a vehicle having a large load weight variation range.

  The main role of the suspension system is to properly ground the tire and to catch the movement of the tire that moves up and down following the unevenness of the road surface, to reduce the vibration of the loading platform and the cabin, and to reduce the vibration of the leaf spring and air There are springs with a shock absorber for damping vibrations, or leaf springs and air springs combined with a shock absorber.

Conventionally, a suspension device has been provided with a shock absorber that is alternatively set to either a soft mode with a small damping force or a hard mode with a large damping force, and the damping force can be switched according to the traveling speed or the judgment of the driver. Has been proposed (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 7-266831

  However, the trucks that serve as the backbone of the logistics system and the route buses that complement urban traffic vary greatly in terms of vehicle loading weight (cargo and passenger weight) due to time, day of the week, season, etc. Even if the suspension device is employed, a damping force commensurate with the load weight cannot be obtained, and there is a case where the suspension device does not contribute to the suppression of the vibration of the loading platform or the passenger compartment.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a suspension device that can obtain a damping force commensurate with the loading weight of a vehicle.

  In order to achieve the above-described object, the present invention provides an air spring interposed between a sprung mass equivalent member and an unsprung mass equivalent member, and connects the sprung mass equivalent member and the unsprung mass equivalent member and provides a damping force. Comprising an electromagnetic shock absorber that increases or decreases in accordance with the electric resistance value, and a controller that calculates the load weight of the vehicle and adjusts the electric resistance value so that the electromagnetic shock absorber can exhibit a damping force commensurate with it. take.

  More specifically, a dynamic braking motor that can rotate following the proximity and separation of the sprung mass equivalent member and the unsprung mass equivalent member is a component of the electromagnetic shock absorber, and a variable resistor is connected between the terminals of the motor. Then, the controller adjusts the electric resistance value.

  In addition, a sensor is provided for detecting the air spring internal pressure, and the controller has a function of calculating the load weight of the vehicle based on the information of the sensor and adjusting the electric resistance value so that the electromagnetic shock absorber can exhibit a damping force commensurate with it. Provide.

  That is, the controller adjusts the damping force of the electromagnetic shock absorber steplessly so as to match the current vehicle loading weight.

  According to the suspension device of the present invention, the following excellent effects can be obtained.

  (1) The damping force of the electromagnetic shock absorber can be adjusted steplessly so as to match the load weight of the vehicle, and the vibration of the loading platform and the passenger compartment can be effectively suppressed.

  (2) Therefore, damage to the cargo due to vibration can be avoided, and the ride quality can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 and 2 show an example of the suspension device of the present invention. An air spring 3 interposed between a sprung mass equivalent member 1 and an unsprung mass equivalent member 2, a sprung mass equivalent member 1 and a spring. An electromagnetic shock absorber 4 that is interposed between the lower mass equivalent members 2 and connects the two, a sensor 5 that detects the internal pressure of the air spring 3, and a command to the electromagnetic shock absorber 4 based on information 6 from the sensor 5 7 is provided.

  Further, 9 represents a tire, and 10 represents a road surface.

  Here, “sprung mass equivalent member” is a generic term for chassis frame components including side rails, and “unsprung mass equivalent member” is a member such as a bracket or leaf spring attached to the axle. Pointing.

  The electromagnetic shock absorber 4 includes a motor bracket 11 also serving as a gear case, a motor 12 whose output shaft is included in the motor bracket 11, an outer cylinder bracket 13 attached to the motor bracket 11 so as to be aligned with the motor 12, and a base A screw shaft 14 included in the motor bracket 11 and rotatably supported by the outer cylinder bracket 13 so that an end thereof is parallel to the output shaft of the motor 12, and a small gear 15 fitted to the output shaft of the motor 12, A large gear 16 fitted to the base end portion of the screw shaft 14 and meshed with the small gear 15, an outer tube 17 attached to the outer tube bracket 13 so as to surround the screw shaft 14 in the circumferential direction, and a ball at the base end portion A hollow rod 19 fitted with a screw nut 18 is provided.

  The ball screw nut 18 is screwed onto the screw shaft 14, and the rod 19 is fitted into the outer cylinder 17 so as not to rotate in the circumferential direction. When the rod 19 is pushed and pulled toward the axis, the ball screw nut 18 is screwed into the screw shaft. This rotation is transmitted to the output shaft of the motor 12 via the large gear 16 and the small gear 15.

  The main purpose of the motor 12 is dynamic braking, and a variable resistor (not shown) is incorporated between its terminals, and the rotational motion transmitted to the output shaft via the small gear 15 is converted into heat and released.

  The resistance value of the variable resistor attached to the motor 12 increases or decreases according to the command 7 transmitted from the controller 8.

  That is, as the resistance value of the variable resistor increases, the rod 19 becomes less likely to be pushed and pulled, and the apparent damping force changes in proportion to the resistance value.

  Further, the motor bracket 11 is fastened to the sprung mass equivalent member 1 and the rod 19 is fastened to the unsprung mass equivalent member 2.

The controller 8 has the following functions.
(1) A function for calculating the current vehicle loading weight W (the internal pressure P of the air spring 3 increases in proportion to the loading weight W) based on the information 6 from the sensor 5.
(2) A function for calculating the numerical value of the attenuation coefficient C necessary to maintain the relationship of μ = C / 2√ (W · k).
μ: Damping ratio (constant), C: Damping coefficient of electromagnetic shock absorber 4, k: Spring constant of air spring 3 (3) The electromagnetic shock absorber 4 calculated for the variable resistor attached to the motor 12 A function of transmitting a command 7 for adjusting a resistance value so as to exhibit an attenuation coefficient C.

  That is, the controller 8 adjusts the damping force of the electromagnetic shock absorber 4 steplessly so as to match the current vehicle loading weight W (so that the damping ratio does not change), and the loading platform connected to the sprung mass equivalent member 1. And vibration of the passenger compartment can be effectively suppressed.

  Therefore, in trucks and buses with a large fluctuation range of the load weight W, cargo damage can be avoided and the ride quality can be improved.

  Note that the suspension device of the present invention is not limited to the above-described embodiment, and it is needless to say that changes can be made without departing from the gist of the present invention.

  The suspension device of the present invention can be applied to various vehicle types.

It is a conceptual diagram which shows an example of the suspension apparatus of this invention. It is a conceptual diagram of the electromagnetic shock absorber relevant to FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sprung mass equivalent member 2 Unsprung mass equivalent member 3 Air spring 4 Electromagnetic shock absorber 5 Sensor 6 Information 8 Controller 12 Motor (power generation braking motor)

Claims (3)

  An air spring interposed between an unsprung mass equivalent member and an unsprung mass equivalent member, and an electromagnetic shock in which the unsprung mass equivalent member and the unsprung mass equivalent member are connected and the damping force increases or decreases according to the electric resistance value. A suspension device comprising: an absorber; and a controller that calculates a load weight of the vehicle and adjusts an electric resistance value so that the electromagnetic shock absorber can exhibit a damping force corresponding to the calculated weight.   A dynamic braking motor that can rotate following the close separation of the sprung mass equivalent member and the unsprung mass equivalent member is a component of the electromagnetic shock absorber, and the terminals of the motor are short-circuited via a variable resistor. The suspension device according to claim 1, wherein the controller adjusts the electric resistance value.   A sensor for detecting the air spring internal pressure is provided, and the controller has a function of calculating the load weight of the vehicle based on the information of the sensor and adjusting the electric resistance value so that the electromagnetic shock absorber can exhibit a damping force corresponding to the calculated weight. The suspension device according to any one of claims 1 and 2.

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