摘要:
The present invention is a control device for a variable displacement hydraulic pump by which the absorption horsepower of the hydraulic pump increases with excellent responsiveness and ON/OFF operations of a cut-off control of the maximum pressure can be selected. To this end, a hydraulic pump (2), a slow return valve (25) and a switching valve (24) placed parallel to each other in a flow path connecting a servo piston (4) and a servo valve (5); a solenoid valve (26), for controlling the pilot pressure of the switching valve (24); and an ON/OFF operation selectable selector (30), connected to a control device (10), are included; and the controlling device (10) outputs a command signal to the solenoid valve (26) when the selector (30) is switched ON to lower the operation speed of the swash plate angle of the hydraulic pump (2).
摘要:
A twin-scrape dozer, capable of maintaining a satisfactory balance during earth loading, of loading a larger quantity of earth, of efficiently conveying earth even over a soft ground, and of adjusting the rate at which earth is scattered, has a crawler type tractor (1, 1A) equipped with a traveling mechanism, a front earth loading and ejecting device (10, 50), and a rear earth loading and ejecting device (30, 70). The traveling mechanism has track frames (2, 2A) at right and left sides of the vehicle (1, 1A), track shoes (5, 5A) and drive units (6, 6A). The earth loading and ejecting devices are provided at the front and rear parts of the vehicle (1, 1A), and are installed to be vertically movable with lift cylinders (13, 33, 56, 78). Each of the earth loading and ejecting devices is provided with a scraper (21, 34, 53, 75) and a bowl member (14, 41, 61, 81) pivotably connected together by pivot pins (22, 42, 62, 83). Each scraper (21, 34, 53, 75) and bowl member (14, 41, 61, 81) are controlled by a bowl cylinder (23, 43, 63, 84), so that the bottom of the bowls (20, 40, 60, 80) can be opened and closed by extending and retracting the respective bowl cylinders (23, 43, 63, 84). The excavating angle of the scrapers (21, 34, 53, 72) can be changed by extending and retracting the tilt cylinders (16, 36) or by adjusting the length of variable length braces (57, 73).
摘要:
A shock absorbing device provided with a damping plate damper having a viscosity damper includes: a case body comprising an upper flange, a body portion, and a lower flange; a collared resilient member provided with a body portion and a collar portion, an outer surface of the body portion and an undersurface of the collar portion being connected to the case body; a center shaft connected to the central portion of the collared resilient member; a damping plate fixed to the bottom end portion of the center shaft; and a damper case fixed to the bottom end of the case body and filled with a viscous substance. An operator cabin of a construction machine is resiliently supported to the vehicle body through the shock absorbing device. For this reason, the number of natural vibration of the operator cabin during high speed running of a hydraulic power shovel is increased, whereby resonance thereof with the gear engaging frequencies of a caterpillar track and a sprocket wheel is avoided, so that effective damping effects can be achieved against the number of excited vibrations applied in wide ranges by the construction machines and the like, thus improving riding comfort for an operator and the mechanical strength of the operator cabin.
摘要:
In construction machinery, control is conducted to keep a work machine to operate at a constant speed regardless of the operation thereof. Different engine output lines T0-T3 and pump torque lines M1-M4 are defined for different operation types. All the matching points of the engine output lines T0-T3 and pump torque lines M1-M4 designate a constant engine speed N1. One engine output line and one pump torque line are selected according to the operation type presently selected. An output horsepower of the engine is controlled on an equal horsepower line corresponding to a sum of a horsepower for an auxiliary machine and a horsepower at a matching point of the selected lines. The pump torque for the work machine is controlled on the selected pump torque line. The engine operates at a constant speed N1 even when the operation type varies or the horsepower for the auxiliary machine changes.
摘要:
A rubber crawler belt having a pattern of a lug provided on an outer circumferential side of a rubber belt has a central lug portion provided to continuously extend around a center portion in a width direction of the outer circumference of the rubber belt, in a waveform, and a plurality of branch lug portions each having a predetermined width and provided from the central lug portion toward left and right end portions of the rubber belt to be away therefrom diagonally in a circumferential direction, and an interval between the branched lug portions adjacent to each other being the same as an interval between drive protrusions, in the circumferential direction of the rubber belt.
摘要:
A workload detecting system for an excavating and loading apparatus, in which a bucket supporting member is vertically pivoted relative to a vehicle body and a bucket is actuated to be tilted with respect to the bucket supporting member. The system includes a bottom pressure detecting system (17) for detecting a bottom pressure of a cylinder (6) for vertically pivoting the bucket supporting member (5, 7), a, bucket earth and sand amount calculating system (18) for calculating an earth and sand weight within the bucket (9) on the basis of the detected bottom pressure, and a bucket earth and sand amount calculating summing system (31) for integrating the calculated bucket earth and sand weight.
摘要:
An apparatus for detecting an amount of metal powder in a hydraulic circuit for supplying a drain pressurized oil from a hydraulic pump driven by an engine is characterized by comprising a metal powder amount detection sensor (9) disposed in a flow passage of the pressurized oil and adapted to transmit a signal in proportion to an adhering amount of the metal powder and a controller (11) for calculating the metal powder amount from the signal outputted from the metal powder detection sensor and displaying the calculated amount.