Constant speed device for tandem vibratory roller
(1) technical field
The present invention relates to a kind of vibratory roller, especially relate to a kind of constant speed device for tandem vibratory roller.Belong to technical field of engineering machinery.
(2) background technology
The theoretical requirement of compacting, the interval strike to ground during double-steel wheeled vibratory roller work is not more than 3cm, and the rolling speed when being equivalent to double-steel wheeled vibratory roller work is at 2.7~5.4km/h.When at present traditional double-steel wheeled vibratory roller was worked, the operator need repeat to push away, draw and adjust the walking joystick, and double-steel wheeled vibratory roller is ceaselessly moved back and forth on flexible pavement in certain speed range.At double-steel wheeled vibratory roller several advance or the speed control operation that retreats in, be difficult to realize that each travel speed of advancing or retreating is the same; The work that repeats so not only makes the operator feel tired easily and is sick of, and the uncertainty of speed control also allows the consolidation effect of double-steel wheeled vibratory roller not reach requirement.
(3) summary of the invention
The objective of the invention is to overcome above-mentioned deficiency, provide a kind of and can realize each the same constant speed device for tandem vibratory roller of the travel speed of advancing or retreating.
The object of the present invention is achieved like this: a kind of constant speed device for tandem vibratory roller, comprise speed change manipulation joystick, A/D change-over circuit, it is characterized in that: described device increases a constant speed mode selector switch on the control panel of double-steel wheeled vibratory roller, this constant speed mode selector switch possesses two constant close contacts and two constant open contacts, and two inputs of this constant speed mode selector switch link to each other with the OUT-end with the OUT+ of speed change manipulation joystick respectively; Output at described constant speed mode selector switch, two normally closed port of this constant speed mode selector switch and the coil two ends of the proportion magnetic valve on the variable traveling pump join, two normal openings of this constant speed mode selector switch join with the 5VIN and the AGND of A/D change-over circuit respectively, and two delivery outlet DB of A/D change-over circuit
oWith DGND respectively with the variable traveling pump on the coil two ends of proportion magnetic valve join.
Operating principle: during not enabled constant speed mode selector switch, speed change handle two constant close contacts of joystick by the constant speed mode selector switch directly and the coil two ends of the proportion magnetic valve on the variable traveling pump join, at this moment can realize the continuous control of analog quantity, thereby realize electrodeless variable-speed; (constant open contact is connected when enabling the constant speed mode selector switch, constant close contact disconnects), the OUT+ that speed change is handled joystick links to each other with AGND with the 5VIN of A/D change-over circuit respectively with the OUT-end, this A/D change-over circuit has bipolarity, can change ± voltage of 5V, can realize the constant of output voltage electric current by this A/D change-over circuit, thereby make that variable walking pump delivery is constant, so road roller can constant-speed operation.
The invention has the beneficial effects as follows:
The double-steel wheeled vibratory roller operating personnel can pass through the constant speed mode selector switch, when double-steel wheeled vibratory roller is worked, do not need to adjust the walking joystick, realize speed control fast to double-steel wheeled vibratory roller, in the working strength that reduces the operator simultaneously, improved the consolidation effect of double-steel wheeled vibratory roller.Avoid operator at double-steel wheeled vibratory roller several advance or the speed control operation that retreats in, be difficult to realize each the same phenomenon of the travel speed of advancing or retreating, reduce the working strength of operator; Rate request when simultaneously satisfying the compacting theory easily double-steel wheeled vibratory roller being worked.This installs simple and practical easy to operate.
(4) description of drawings
Fig. 1 is the theory diagram of constant speed device for tandem vibratory roller of the present invention.
Reference numeral among the figure:
Speed change is handled joystick 3, constant speed mode selector switch 4, A/D change-over circuit 5, variable traveling pump 6.
(5) specific embodiment
Referring to Fig. 1, Fig. 1 is the theory diagram of constant speed device for tandem vibratory roller of the present invention.As seen from Figure 1, constant speed device for tandem vibratory roller of the present invention, comprise speed change manipulation joystick 3, A/D change-over circuit 5, be characterized in: it is to increase a constant speed mode selector switch 4 on the control panel of double-steel wheeled vibratory roller, this constant speed mode selector switch 4 possesses two constant close contact 1-b, 2-d and two constant open contact 1-a, 2-c, and two inputs 1 of this constant speed mode selector switch 4 link to each other with the OUT-end with the OUT+ of speed change manipulation joystick 3 respectively with 2.Output at constant speed mode selector switch 4, two normally closed port b of this constant speed mode selector switch 4 and d respectively with variable traveling pump 6 on loop A, the B two ends of proportion magnetic valve join respectively, two normal opening a of this constant speed mode selector switch 4 and c join with the 5VIN and the AGND of A/D change-over circuit 5 respectively, and two delivery outlet DB of A/D change-over circuit 5
oWith DGND respectively with the variable traveling pump on loop A, the B two ends of proportion magnetic valve join.
Its effect is mainly by constant speed mode selector switch 4 action, and speed change is handled the analog quantity signal of telecommunication of the proportion magnetic valve (control traveling pump discharge capacity) that joystick 3 is delivered to variable traveling pump 6, changes a switching value signal into by A/D change-over circuit 5.When the unlatching of constant speed pattern, speed change is handled joystick 3 and just is equivalent to a switch, and speed change manipulation joystick is operated forward or backward and is delivered to
What the proportion magnetic valve of variable traveling pump 6 obtained all is the fixed signal of advancing or retreating, and the pump delivery of variable walking at this moment is constant, thereby realizes the constant airspeed that advances or retreat of double-steel wheeled vibratory roller.