CN114889572B - Automatic parking braking hydraulic system of wheeled engineering truck - Google Patents
Automatic parking braking hydraulic system of wheeled engineering truck Download PDFInfo
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- CN114889572B CN114889572B CN202210813479.5A CN202210813479A CN114889572B CN 114889572 B CN114889572 B CN 114889572B CN 202210813479 A CN202210813479 A CN 202210813479A CN 114889572 B CN114889572 B CN 114889572B
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
- B60T13/10—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release
- B60T13/66—Electrical control in fluid-pressure brake systems
- B60T13/68—Electrical control in fluid-pressure brake systems by electrically-controlled valves
- B60T13/686—Electrical control in fluid-pressure brake systems by electrically-controlled valves in hydraulic systems or parts thereof
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Abstract
The invention discloses an automatic parking brake hydraulic system of a wheeled engineering truck, which comprises a hydraulic oil tank, a main pump, a shuttle valve, a duplex electromagnetic valve, a pressure reducing valve, a pedal valve, a two-position two-way electromagnetic directional valve, a first one-way valve, a second one-way valve, a pressure sensor, an energy accumulator, a delay valve, a first two-position three-way electromagnetic valve, a spring brake cylinder, a walking motor, an electric switch group and a main valve. The advantages are that: the invention can automatically start the parking brake after the wheel type excavator stops, does not need manual operation, and can prevent the vehicle sliding accident caused by the fact that a driver forgets to press the parking switch; the invention can lead the driver of the wheel type excavator to start and stop more stably on the slope; the invention can avoid the damage of the walking motor caused by the sliding without stepping on the accelerator when the driver runs on the downhill for a long time.
Description
Technical Field
The invention relates to an automatic parking brake hydraulic system of a wheel type engineering truck, and belongs to the technical field of engineering machinery.
Background
At present, the parking brake of the wheel type excavator is mostly hydraulic brake, and a parking switch can directly control a spring brake cylinder in an axle to lock the axle by controlling pressure oil. However, the parking switch is required to be manually pressed, so that forgetfulness is easy to occur, the function is too simple, and the complex working condition requirements cannot be met. When the wheel type excavator starts on a slope, if the accelerator is not stepped on in time after the parking switch is loosened, the problem of vehicle sliding can occur, the driving experience is influenced, and potential safety hazards exist; when a vehicle goes down a slope for a long time, many customers can slide the vehicle without stepping on an accelerator, and because the wheel type excavator is different from the automobile, the wheel type excavator is driven by a walking motor, and the accelerator is not stepped on when the vehicle goes down the slope, the whole vehicle is dragged forward by inertia, and the motor is dragged forward more and more quickly, so that the walking motor is damaged due to air suction.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides an automatic parking brake hydraulic system of a wheel type engineering truck.
In order to solve the technical problems, the invention provides an automatic parking brake hydraulic system of a wheel type engineering truck,
the hydraulic control system comprises a hydraulic oil tank, a main pump, a shuttle valve, a duplex electromagnetic valve, a pressure reducing valve, a pedal valve, a two-position two-way electromagnetic directional valve, a first one-way valve, a second one-way valve, a pressure sensor, an energy accumulator, a delay valve, a first two-position three-way electromagnetic valve, a spring brake cylinder, a walking motor, an electric switch group and a main valve;
an oil inlet of the main pump is connected with a hydraulic oil tank; an oil outlet of a first pump of the main pump is connected with an oil inlet of the main valve; the first main oil port of the main valve is connected with the first main oil port of the walking motor, and the second main oil port of the main valve is connected with the second main oil port of the walking motor; an oil outlet of a second pump of the main pump is connected with an oil inlet of the foot valve and an oil inlet of the pressure reducing valve; an oil outlet of the foot valve is connected with an oil inlet of the duplex solenoid valve; a first oil outlet of the duplex solenoid valve is connected with a first pilot oil port of the main valve and a first oil port of the shuttle valve, and a second oil outlet of the duplex solenoid valve is connected with a second pilot oil port of the main valve and a second oil port of the shuttle valve; a first oil outlet of the shuttle valve is connected with a second oil inlet of the delay valve; one path of an oil outlet of the pressure reducing valve is connected with an oil inlet of the two-position two-way electromagnetic reversing valve, and the other path of the oil outlet of the pressure reducing valve is connected with a first oil inlet of the energy accumulator, the pressure sensor and the time delay valve after passing through the second one-way valve; the oil outlet of the two-position two-way electromagnetic reversing valve is connected with the second oil inlet of the delay valve through a first one-way valve; an oil outlet of the delay valve is connected with an oil inlet of a first two-position three-way electromagnetic valve, and an oil outlet of the first two-position three-way electromagnetic valve is connected with a rod cavity of the spring brake cylinder; the return oil of the duplex solenoid valve, the foot valve, the pressure reducing valve, the time delay valve and the first two-position three-way solenoid valve is connected with a hydraulic oil tank; and the electric switch group is used for respectively controlling the first two-position three-way electromagnetic valve, the two-position two-way electromagnetic reversing valve and the duplex electromagnetic valve to be electrified.
Further, the main pump comprises a plunger pump and a gear pump, the plunger pump and the gear pump rotate coaxially, an oil outlet P1 of the plunger pump is a first pump oil outlet, and an oil outlet P2 of the gear pump is a second pump oil outlet.
Further, the duplex solenoid valve comprises a second two-position three-way solenoid valve and a third two-position three-way solenoid valve;
the oil inlet of the second two-position three-way solenoid valve and the oil inlet of the third two-position three-way solenoid valve are connected to be used as an oil inlet P of the duplex solenoid valve, the oil return port of the second two-position three-way solenoid valve and the oil return port of the third two-position three-way solenoid valve are connected to be used as an oil return port of the duplex solenoid valve, the oil outlet A3 of the second two-position three-way solenoid valve is a first oil outlet of the duplex solenoid valve, and the oil outlet A4 of the third two-position three-way solenoid valve is a second oil outlet of the duplex solenoid valve.
Furthermore, the delay valve comprises a first two-position two-way hydraulic control reversing valve, a second two-position two-way hydraulic control reversing valve and a speed regulating valve;
an oil inlet of the first two-position two-way hydraulic control reversing valve is used as a first oil inlet of the delay valve;
the pilot oil inlets of the first two-position two-way hydraulic control reversing valve and the second two-position two-way hydraulic control reversing valve are connected to be used as a second oil inlet of the delay valve;
the oil outlets of the first two-position two-way hydraulic control reversing valve and the second two-position two-way hydraulic control reversing valve are connected to be used as the oil outlet of the delay valve;
the oil return ports of the first two-position two-way hydraulic control reversing valve, the second two-position two-way hydraulic control reversing valve and the speed regulating valve are connected to be used as oil return ports of the delay valve;
the speed regulating valve adopts a speed regulating valve with an adjustable throttle valve inside
Further, the walking motor comprises a plunger motor, an overflow valve and a balance valve;
the plunger motor, the overflow valve and the upper oil port of the balance valve are connected as the oil outlet or the oil inlet of the walking motor;
and the plunger motor, the overflow valve and the lower oil port of the balance valve are connected to be used as an oil outlet or an oil inlet of the walking motor.
Further, the electrical switch group comprises a normally closed switch PB1, a normally open switch PB2 and a selection switch PB3;
one ends of the normally closed switch PB1, the normally open switch PB2 and the selection switch PB3 are connected with the positive electrode of the power supply together;
the other end of the normally-closed switch is connected with the negative electrode of the power supply after being connected with the first two-position three-way electromagnetic valve, the other end of the normally-open switch is connected with the negative electrode of the power supply after being connected with the two-position two-way electromagnetic reversing valve, the first selection contact of the selection switch is connected with the negative electrode of the power supply after being connected with the second two-position three-way electromagnetic valve, and the second selection contact of the selection switch is connected with the negative electrode of the power supply after being connected with the third two-position three-way electromagnetic valve.
Further, the wheel type engineering truck is a wheel type excavator.
The invention achieves the following beneficial effects:
(1) The invention can automatically start the parking brake after the wheel type excavator stops, does not need manual operation, and can prevent the vehicle sliding accident caused by the fact that a driver forgets to press the parking switch;
(2) The invention can lead the driver of the wheel type excavator to start and stop more stably on the slope;
(3) The invention can avoid the damage of the walking motor caused by the sliding without stepping on the accelerator when the driver runs on the downhill for a long time.
Drawings
FIG. 1 is a block schematic diagram of the present control system;
FIG. 2 is a schematic illustration of the composition of the main pump of FIG. 1;
FIG. 3 is a schematic diagram of the components of the dual solenoid valve of FIG. 1;
FIG. 4 is a schematic illustration of the components of the delay valve of FIG. 1;
FIG. 5 is a schematic view of the travel motor of FIG. 1;
FIG. 6 is a schematic diagram of the electrical switch bank of FIG. 1;
in the figure, 1 is a hydraulic oil tank, 2 is a main pump, 3 is a shuttle valve, 4 is a duplex electromagnetic valve, 5 is a foot valve, 6 is a pressure reducing valve, 7 is a two-position two-way electromagnetic directional valve, 8 is a first one-way valve, 9 is a pressure sensor, 10 is a second one-way valve, 11 is an energy accumulator, 12 is a delay valve, 13 is a first two-position three-way electromagnetic valve, 14 is a spring brake cylinder, 15 is a walking motor, 16 is an electrical switch group, 17 is a main valve, 2-1 is a plunger pump, 2-2 is a gear pump, 4-1 is a second two-position three-way electromagnetic valve, 4-2 is a third two-position three-way electromagnetic valve, 12-1 is a first two-position two-way hydraulic directional valve, 12-2 is a second two-position two-way hydraulic directional valve, 12-3 is a speed regulating valve, 12-3-1 is an adjustable throttle valve, 15-1 is a plunger motor, 15-2 is an overflow valve, and 15-3 is a balance valve.
Detailed Description
The invention is further described below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.
As shown in fig. 1, an electro-hydraulic control system for automatic parking braking of a wheel type engineering truck comprises a hydraulic oil tank 1, a main pump 2, a shuttle valve 3, a duplex electromagnetic valve 4, a foot valve 5, a pressure reducing valve 6, a two-position two-way electromagnetic directional valve 7, a first check valve 8, a second check valve 10, a pressure sensor 9, an energy accumulator 11, a delay valve 12, a first two-position three-way electromagnetic valve 13, a spring brake cylinder 14, a traveling motor 15, an electric switch group 16 and a main valve 17.
The specific positions and connection relations of the components are as follows: an oil inlet S of the main pump 2 is connected with the hydraulic oil tank 1; an oil outlet P1 of a plunger pump of the main pump 2 is connected with an oil inlet P of a main valve 17; a first main oil port AO of the main valve 17 is connected with a first main oil port a of the traveling motor 15, and a second main oil port BO of the main valve 17 is connected with a second main oil port B of the traveling motor 15; an oil outlet P2 of a gear pump of the main pump 2 is connected with an oil inlet P of a foot valve 5 and an oil inlet P of a pressure reducing valve 6; the third oil outlet A3 of the duplex solenoid valve 4 is connected with a first pilot oil port XAO of a main valve 17 and a first oil port X1 of a shuttle valve 3, and the fourth oil outlet A4 of the duplex solenoid valve 4 is connected with a second pilot oil port XBO of the main valve 17 and a second oil port X2 of the shuttle valve; a first oil outlet A1 of the shuttle valve 3 is connected with a second oil inlet P2 of the delay valve 12; one path of an oil outlet A of the pressure reducing valve 6 is connected with an oil inlet P of the electromagnetic valve 7, and the other path of the oil outlet A passes through a second one-way valve 10 and then is connected with an energy accumulator 11, a pressure sensor 9 and a first oil inlet P1 of the delay valve; an oil outlet A of the electromagnetic valve 7 is connected with a second oil inlet P2 of the delay valve 12 through a first one-way valve 8; an oil outlet A of the delay valve 12 is connected with an oil inlet P of the electromagnetic valve 13, and an oil outlet A of the electromagnetic valve 13 is connected with a rod cavity of the spring brake cylinder; the return oil of the duplex electromagnetic valve 4, the foot valve 5, the reducing valve 6, the delay valve 12 and the electromagnetic valve 13 is connected with the hydraulic oil tank 1; the normally closed switch PB1 in the electrical switch group 16 controls the electromagnetic valve 13 to be electrified, the normally open switch PB2 controls the electromagnetic valve 7 to be electrified, and the selector switch PB3 controls the duplex electromagnetic valve 4 to be electrified.
As shown in fig. 2, the main pump 2 is composed of a 2-1 plunger pump and a 2-2 gear pump, the plunger pump 2-1 and the gear pump 2-2 rotate coaxially, an oil outlet P1 of the plunger pump 2-1 is a first pump oil outlet, and an oil outlet P2 of the gear pump 2-2 is a second pump oil outlet.
As shown in fig. 3, the duplex solenoid valve 4 is composed of a 4-1 two-position three-way solenoid valve and a 4-2 two-position three-way solenoid valve; an oil inlet of the second two-position three-way solenoid valve 4-1 and an oil inlet of the third two-position three-way solenoid valve 4-2 are connected to serve as an oil inlet P of the duplex solenoid valve 4, an oil return port of the second two-position three-way solenoid valve 4-1 and an oil return port of the third two-position three-way solenoid valve 4-2 are connected to serve as an oil return port of the duplex solenoid valve 4, an oil outlet A3 of the second two-position three-way solenoid valve 4-1 is a first oil outlet of the duplex solenoid valve 4, and an oil outlet A4 of the third two-position three-way solenoid valve 4-1 is a second oil outlet of the duplex solenoid valve 4.
As shown in fig. 4, the delay valve consists of a 12-1 two-position two-way hydraulic control reversing valve, a 12-2 two-position two-way hydraulic control reversing valve and a 12-3 speed regulating valve, and a 12-3-1 adjustable throttle valve is arranged in the speed regulating valve. An oil inlet of the first two-position two-way hydraulic control reversing valve 12-1 is used as a first oil inlet P1 of the delay valve 12; the pilot oil inlets of the first two-position two-way hydraulic control reversing valve 12-1 and the second two-position two-way hydraulic control reversing valve 12-2 are connected to be used as a second oil inlet P2 of the delay valve 12; the oil outlets of the first two-position two-way hydraulic control reversing valve 12-1 and the second two-position two-way hydraulic control reversing valve 12-2 are connected to be used as an oil outlet A of the delay valve 12; the oil return ports of the first two-position two-way hydraulic control reversing valve 12-1, the second two-position two-way hydraulic control reversing valve 12-2 and the speed regulating valve 12-3 are connected to be used as the oil return port T of the delay valve 12; the speed regulating valve adopts a speed regulating valve with an adjustable throttle valve 12-3-1 inside, is used for regulating the oil return speed of pressure oil, and is intuitively represented as regulating the delay time of the delay valve to enable the spring brake cylinder to be still in an unlocking state before the vehicle stops.
As shown in FIG. 5, the traveling motor is composed of a 15-1 plunger motor, a 15-2 overflow valve, a 15-3 balance valve, and the like. The plunger motor 15-1, the overflow valve 15-2 and the upper end oil port of the balance valve 15-3 are connected to obtain a port A, and the port A is an oil outlet or an oil inlet of the walking motor 15; the plunger motor 15-1, the overflow valve 15-2 and the lower end oil port of the balance valve 15-3 are connected to obtain a port B, and the port B is used as an oil outlet or an oil inlet of the walking motor; because the motor rotates positively and negatively, the ports A and B can be oil inlets or oil return ports.
As shown in fig. 6, the electrical switching group includes a normally closed switch PB1, a normally open switch PB2, and a selector switch PB3. One ends of the normally closed switch PB1, the normally open switch PB2 and the selection switch PB3 are connected with the positive electrode of the power supply together;
the other end of the normally closed switch is connected with the negative pole of the power supply after being connected with the first two-position three-way electromagnetic valve 13, the other end of the normally open switch is connected with the negative pole of the power supply after being connected with the two-position two-way electromagnetic reversing valve 7, the first selection contact of the selection switch is connected with the negative pole of the power supply after being connected with the second two-position three-way electromagnetic valve 4-1, and the second selection contact of the selection switch is connected with the negative pole of the power supply after being connected with the third two-position three-way electromagnetic valve 4-2.
The specific application principle of the invention is as follows
When the normally closed switch PB1 is opened, 1YA is de-energized, and the first two-position three-way solenoid valve 13 is at the upper position. The spring brake cylinder 14 is normally closed, and the vehicle cannot walk; 1YA denotes an electromagnet of the solenoid valve 13.
When the normally closed switch PB1 is closed and the normally open switch PB2 is opened, 1YA is powered on, 2YA is not powered on, the first two-position three-way electromagnetic valve 13 is at the lower position, and the electromagnetic valve 7 is at the upper position. The pressure oil of the gear pump P2 is decompressed through a pressure reducing valve 6, enters a port of a delay valve 12P2 after passing through an electromagnetic valve 7 and a first one-way valve 8, and pushes a two-position two-way reversing valve in the delay valve 12 to a right position; the other path of pressure oil after pressure reduction acts on a rod cavity of a spring brake cylinder 14 after passing through a second one-way valve 10, a delay valve 12 and an electromagnetic valve 13, the spring is stressed to retract, and parking brake is released; 2YA denotes an electromagnet of the solenoid valve 7.
When the normally closed switch PB1 is closed, the normally open switch PB2 is closed, and the selection switch PB3 selects the left position, and when the driver does not step on the foot valve 5, the 1YA, the 2YA, and the 3YA are energized, the first two-position three-way electromagnetic valve 13 is at the lower position, the electromagnetic valve 7 is at the lower position, and the second two-position three-way electromagnetic valve 4-1 is at the right position. The pressure oil of the gear pump P2 is decompressed by the pressure reducing valve 6 and acts on a port P1 of the delay valve through the second check valve 10, the other path of pressure oil at the outlet of the pressure reducing valve is blocked by the electromagnetic valve 7, the port P2 of the delay valve has no pressure oil action, the pressure oil at the port P1 of the delay valve cannot pass through the delay valve, and the parking brake is not released at the moment; when a driver steps on the foot valve 5 to enable a pedal to generate displacement, pressure oil of a gear pump P2 reaches a port of a delay valve P2 through the foot valve 5, an A3 port of a duplex solenoid valve 4 and a shuttle valve 3 to push a first two-position two-way hydraulic control reversing valve 12-1 and a second two-position two-way hydraulic control reversing valve 12-2 in the delay valve 12 to perform transposition, the pressure oil of the port P1 of the delay valve acts on a rod cavity of a spring brake cylinder 14 through the delay valve 12 and a first two-position three-way solenoid valve 13, the spring is stressed and retracted, parking braking is relieved, the pressure oil acts on a first pilot oil port XAO of a main valve 16, a valve core of the main valve 17 is in a left position, a first main BO oil port AO and a second main oil port AO are respectively communicated with a first main oil port A and a second main oil port B of a walking motor 15, the walking motor rotates, and the vehicle starts to walk; when the driver releases the foot valve, the first pilot oil port XAO of the main valve 17 has no pressure oil effect, the valve core of the main valve 17 returns to the middle position, the oil circuit connected with the walking motor is closed, the vehicle continues to advance under inertia, the anti-dragging walking motor continues to rotate, and the pressure oil in the walking motor continues to circulate through the overflow valve until the vehicle stops. When the vehicle runs by inertia, pressure oil at a port P2 of the delay valve 12 returns to the oil tank 1 through the shuttle valve 3 and the electromagnetic valve 4, the second two-position two-way hydraulic control reversing valve 12-2 is at a lower position under the action of spring force, and pressure oil in a rod cavity of the spring brake cylinder 14 returns to the hydraulic oil tank 1 after passing through the first two-position three-way electromagnetic valve 13 and the delay valve 12. The adjustable throttle valve 12-3-1 in the delay valve 12 can adjust the oil return speed of pressure oil, so that the spring brake cylinder is still in an unlocked state before the vehicle stops; 3YA denotes an upper electromagnet of the solenoid valve 4.
When the normally closed switch PB1 is closed, the normally open switch PB2 is also closed, and the selector switch PB3 selects the neutral position, the 1YA and the 2YA are energized, the 3YA and the 4YA are not energized, the first two-position three-way electromagnetic valve 13 is in the lower position, the electromagnetic valve 7 is in the lower position, and the second two-position three-way electromagnetic valve 4-1 and the third two-position three-way electromagnetic valve 4-2 are in the left position. Pressure oil of the gear pump P2 is decompressed by the decompression valve 6 and then acts on a port P1 of the delay valve through the second one-way valve 10, the other path of pressure oil at the outlet of the decompression valve is blocked by the electromagnetic valve 7, and pressure oil from the pedal valve 5 is blocked by the electromagnetic valve 4, so that no pressure oil acts on the port P2 of the delay valve no matter whether a driver steps on the pedal valve, the pressure oil at the port P1 of the delay valve cannot pass through the delay valve, and parking braking is not released; 4YA represents the electromagnet below the electromagnetic valve 4, and the name given to the electromagnet is mainly used for distinguishing which electromagnet in the electromagnetic valve is electrified, and is shown in a schematic diagram.
When the normally closed switch PB1 is closed, the normally open switch PB2 is closed, and the selection switch PB3 selects the right position, and when the driver does not step on the foot valve 5, the 1YA, the 2YA, and the 4YA are energized, the first two-position three-way electromagnetic valve 13 is in the lower position, the electromagnetic valve 7 is in the lower position, and the third two-position three-way electromagnetic valve 4-2 is in the right position. The pressure oil of the gear pump P2 is decompressed by the pressure reducing valve 6 and acts on a port P1 of the delay valve through the second check valve 10, the other path of pressure oil at the outlet of the pressure reducing valve is blocked by the electromagnetic valve 7, the port P2 of the delay valve has no pressure oil action, the pressure oil at the port P1 of the delay valve cannot pass through the delay valve, and the parking brake is not released at the moment; when a driver steps on the foot valve 5 to enable the pedal to generate displacement, pressure oil of a gear pump P2 reaches a port of a delay valve P2 through the foot valve 5, a fourth oil outlet A4 of a duplex solenoid valve 4 and a shuttle valve 3 to push a first two-position two-way hydraulic control reversing valve 12-1 and a second two-position two-way hydraulic control reversing valve 12-2 inside the delay valve 12 to perform transposition, the pressure oil of the port P1 of the delay valve acts on a rod cavity of a spring brake cylinder 14 through the delay valve 12 and a first two-position three-way solenoid valve 13, the spring is stressed and retracted, parking braking is relieved, the pressure oil acts on a second pilot oil port XBO of a main valve 17, a valve core of the main valve 17 is in a left position, a first main oil port AO and a second main oil port BO of the main valve 17 are respectively communicated with a second main oil port B and a first main oil port A of a traveling motor 15, the traveling motor rotates, and the vehicle starts to travel; when the driver releases the foot valve, the second pilot oil port XBO of the main valve 17 has no pressure oil effect, the valve core of the main valve 17 returns to the middle position, the oil way connected with the traveling motor is closed, the vehicle continues to advance under the inertia, the anti-dragging traveling motor continues to rotate, and the pressure oil in the traveling motor continues to circulate through the overflow valve until the vehicle stops. When the vehicle runs by inertia, pressure oil at a port P2 of the delay valve 12 returns to the oil tank 1 through the shuttle valve 3 and the electromagnetic valve 4, the second two-position two-way hydraulic control reversing valve 12-2 is at a lower position under the action of spring force, and pressure oil in a rod cavity of the spring brake cylinder 14 returns to the hydraulic oil tank 1 after passing through the first two-position three-way electromagnetic valve 13 and the delay valve 12. The adjustable throttle valve 12-3-1 in the delay valve 12 can adjust the oil return speed of pressure oil, so that the spring brake cylinder is still in an unlocked state before the vehicle stops.
When an emergency occurs, the button PB1 can be directly pressed, so that the pressure oil in the rod cavity of the spring brake cylinder 14 directly returns to the hydraulic oil tank without passing through a delay valve, and an emergency braking effect is achieved.
The invention uses the pilot oil of the main valve core as the pilot oil of the pressure oil of the unlocking spring brake cylinder, and can realize unlocking parking brake while the valve core is transposed; the delay valve is used for slowing down the oil return speed of the spring brake cylinder and prolonging the oil return time, so that the parking brake is still in an unlocked state in the period from the time when a driver releases the accelerator to decelerate to stop; the delay valve uses an adjustable throttle valve, so that the time for starting the parking brake can be conveniently adjusted; a two-position two-way hydraulic control reversing valve is added in front of the speed regulating valve in the delay valve, so that pressure oil can be prevented from leaking from the speed regulating valve when the spring brake cylinder is unlocked; an automatic parking switch is arranged, so that a driver can select to turn on or off the automatic parking function; the energy accumulator is arranged to prevent the spring brake cylinder from being damaged by pressure mutation, and meanwhile, the energy accumulator is used as a spare oil source to provide pressure oil required by parking braking when the pump is damaged; and a pressure sensor is arranged to monitor the parking brake pressure in real time, and an automatic alarm is given when the pressure is too low or too high.
The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.
Claims (6)
1. An automatic parking brake hydraulic system of a wheel type engineering truck is characterized in that,
the hydraulic control system comprises a hydraulic oil tank (1), a main pump (2), a shuttle valve (3), a duplex solenoid valve (4), a pressure reducing valve (6), a foot valve (5), a two-position two-way electromagnetic directional valve (7), a first one-way valve (8), a second one-way valve (10), a pressure sensor (9), an energy accumulator (11), a time delay valve (12), a first two-position three-way solenoid valve (13), a spring brake cylinder (14), a traveling motor (15), an electric switch group (16) and a main valve (17);
wherein an oil inlet of the main pump (2) is connected with the hydraulic oil tank (1); an oil outlet of a first pump of the main pump (2) is connected with an oil inlet of a main valve (17); a first main oil port of the main valve (17) is connected with a first main oil port of the traveling motor (15), and a second main oil port of the main valve (17) is connected with a second main oil port of the traveling motor (15); an oil outlet of a second pump of the main pump (2) is connected with an oil inlet of the foot valve (5) and an oil inlet of the pressure reducing valve (6); an oil outlet of the foot valve (5) is connected with an oil inlet of the duplex electromagnetic valve (4); a first oil outlet of the duplex solenoid valve (4) is connected with a first pilot oil port of the main valve (17) and a first oil port of the shuttle valve (3), and a second oil outlet of the duplex solenoid valve (4) is connected with a second pilot oil port of the main valve (17) and a second oil port of the shuttle valve (3); a first oil outlet of the shuttle valve (3) is connected with a second oil inlet of the delay valve (12); one path of an oil outlet of the pressure reducing valve (6) is connected with an oil inlet of the two-position two-way electromagnetic directional valve (7), and the other path of the oil outlet of the pressure reducing valve passes through the second one-way valve (10) and then is connected with a first oil inlet of the energy accumulator (11), the pressure sensor (9) and the delay valve (12); an oil outlet of the two-position two-way electromagnetic reversing valve (7) is connected with a second oil inlet of the time delay valve (12) through a first one-way valve (8); an oil outlet of the delay valve (12) is connected with an oil inlet of a first two-position three-way electromagnetic valve (13), and an oil outlet of the first two-position three-way electromagnetic valve (13) is connected with a rod cavity of the spring brake cylinder (14); the return oil of the duplex electromagnetic valve (4), the foot valve (5), the pressure reducing valve (6), the delay valve (12) and the first two-position three-way electromagnetic valve (13) is connected with the hydraulic oil tank (1); the electric switch group (16) is used for respectively controlling the first two-position three-way electromagnetic valve (13), the two-position two-way electromagnetic directional valve (7) and the duplex electromagnetic valve (4) to be electrified;
the delay valve (12) comprises a first two-position two-way hydraulic control reversing valve (12-1), a second two-position two-way hydraulic control reversing valve (12-2) and a speed regulating valve (12-3); an oil inlet of the first two-position two-way hydraulic control reversing valve (12-1) is used as a first oil inlet of the delay valve (12); pilot oil inlets of the first two-position two-way hydraulic control reversing valve (12-1) and the second two-position two-way hydraulic control reversing valve (12-2) are connected to be used as a second oil inlet of the delay valve (12); the oil outlets of the first two-position two-way hydraulic control reversing valve (12-1) and the second two-position two-way hydraulic control reversing valve (12-2) are connected to be used as the oil outlet of the delay valve (12); the oil return ports of the first two-position two-way hydraulic control reversing valve (12-1), the second two-position two-way hydraulic control reversing valve (12-2) and the speed regulating valve (12-3) are connected to be used as the oil return port of the delay valve (12); the speed regulating valve adopts a speed regulating valve with an adjustable throttle valve (12-3-1) inside.
2. The automatic parking brake hydraulic system for wheeled machineshop truck of claim 1, wherein,
the main pump (2) comprises a plunger pump (2-1) and a gear pump (2-2), the plunger pump (2-1) and the gear pump (2-2) rotate coaxially, an oil outlet P1 of the plunger pump (2-1) is a first pump oil outlet, and an oil outlet P2 of the gear pump (2-2) is a second pump oil outlet.
3. The automatic parking brake hydraulic system for wheeled machineshop truck as claimed in claim 1,
the duplex solenoid valve (4) comprises a second two-position three-way solenoid valve (4-1) and a third two-position three-way solenoid valve (4-2);
an oil inlet of the second two-position three-way electromagnetic valve (4-1) and an oil inlet of the third two-position three-way electromagnetic valve (4-2) are connected to serve as an oil inlet P of the duplex electromagnetic valve (4), an oil return port of the second two-position three-way electromagnetic valve (4-1) and an oil return port of the third two-position three-way electromagnetic valve (4-2) are connected to serve as an oil return port of the duplex electromagnetic valve (4), an oil outlet A3 of the second two-position three-way electromagnetic valve (4-1) is a first oil outlet of the duplex electromagnetic valve (4), and an oil outlet A4 of the third two-position three-way electromagnetic valve (4-1) is a second oil outlet of the duplex electromagnetic valve (4).
4. The automatic parking brake hydraulic system for wheeled machineshop truck as claimed in claim 1,
the walking motor (15) comprises a plunger motor (15-1), an overflow valve (15-2) and a balance valve (15-3);
oil ports at the upper ends of the plunger motor (15-1), the overflow valve (15-2) and the balance valve (15-3) are connected to be used as an oil outlet or an oil inlet of the walking motor (15);
the plunger motor (15-1), the overflow valve (15-2) and the lower end oil port of the balance valve (15-3) are connected to be used as an oil outlet or an oil inlet of the walking motor (15).
5. The automatic parking brake hydraulic system for wheeled machineshop truck according to claim 3, wherein the electrical switch group (16) includes a normally closed switch PB1, a normally open switch PB2, and a selector switch PB3;
one ends of the normally closed switch PB1, the normally open switch PB2 and the selection switch PB3 are connected with the positive electrode of the power supply together;
the other end of the normally closed switch is connected with the power supply cathode after being connected with the first two-position three-way electromagnetic valve (13), the other end of the normally open switch is connected with the power supply cathode after being connected with the two-position two-way electromagnetic reversing valve (7), the first selection contact of the selection switch is connected with the power supply cathode after being connected with the second two-position three-way electromagnetic valve (4-1), and the second selection contact of the selection switch is connected with the power supply cathode after being connected with the third two-position three-way electromagnetic valve (4-2).
6. The automatic parking brake hydraulic system for wheeled machineshop truck as claimed in claim 1,
the wheel type engineering vehicle is a wheel type excavator.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210813479.5A CN114889572B (en) | 2022-07-12 | 2022-07-12 | Automatic parking braking hydraulic system of wheeled engineering truck |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210813479.5A CN114889572B (en) | 2022-07-12 | 2022-07-12 | Automatic parking braking hydraulic system of wheeled engineering truck |
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| CN114889572A CN114889572A (en) | 2022-08-12 |
| CN114889572B true CN114889572B (en) | 2022-10-21 |
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| CN202210813479.5A Active CN114889572B (en) | 2022-07-12 | 2022-07-12 | Automatic parking braking hydraulic system of wheeled engineering truck |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN116517905A (en) * | 2023-06-19 | 2023-08-01 | 江苏汇智高端工程机械创新中心有限公司 | Electrohydraulic reversing valve for override of hydraulic control |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR200299327Y1 (en) * | 2002-07-29 | 2003-01-03 | 정보문 | parking brake auto control system |
| CN103112792B (en) * | 2013-03-01 | 2015-03-25 | 中国海洋石油总公司 | Integrated control valve of logging winch and logging winch system |
| CN105459992B (en) * | 2015-03-16 | 2018-02-09 | 贵州詹阳动力重工有限公司 | A kind of parking control method and device of wheel type hydraulic engineering truck |
| CN110182192B (en) * | 2019-06-28 | 2024-03-26 | 徐州徐工特种工程机械有限公司 | Slip misoperation-preventing parking brake hydraulic system and control method thereof |
| CN111634277A (en) * | 2020-06-04 | 2020-09-08 | 安徽合力股份有限公司 | Braking integrated valve block and double-loop wet braking system applying same |
| CN112590736B (en) * | 2021-01-12 | 2021-10-29 | 中国煤炭科工集团太原研究院有限公司 | Intelligent active and passive combined braking system and method for mine explosion-proof vehicle |
| CN112937535B (en) * | 2021-04-08 | 2022-04-19 | 中铁工程装备集团有限公司 | Hydraulic parking and emergency trailer control device and wheeled engineering vehicle |
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