JP3513993B2 - Start assistance device for vehicles - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention simplifies operating conditions and eliminates the need for a control unit (controller).
Using the devices (switches) currently on the vehicle,
The present invention relates to a start assist device that operates only when starting. 2. Description of the Related Art Conventionally, in a rear two-axle wheel (one shaft is a drive shaft and the other shaft is a driven shaft), startability may be poor due to insufficient axle weight of the drive shaft. In order to solve this problem, Japanese Patent Application No. 6-184528 and Japanese Patent Application No. 6-2497 have proposed a device in which the axle weight of the drive shaft is increased to improve the startability.
No. 53 and the like. [0003] Problems to be Solved by the Invention Japanese Patent Application No. 6-18452
The invention of No. 8 improves the driving force at the time of starting the vehicle by providing an air spring for adjusting the ground pressure of the drive shaft, detecting a change in the shaft load with a level sensor, and controlling the operation of the air spring. However, when the driver operates a switch to turn on and off the start assist device, there is a problem in that the driver forgets to operate the switch. In the invention of Japanese Patent Application No. 6-249753, a vehicle speed sensor and an axle load sensor (level sensor) are provided to automatically turn on and off the start assist device, and the control is performed by a control unit. It was necessary to provide a sensor and a control unit. The present invention provides an apparatus that solves this problem. [0004] A vehicle equipped with the start assist device of the present invention has two rear axles, one of which is axle.
The axis is a drive axis and the other axis is a driven axis. The drive shaft is provided with an air spring for increasing the contact pressure of the tire. An air tank for supplying air to the air spring;
An electromagnetic valve is provided in the middle of an air pipe connecting the air spring and the air tank, and supplies an air from the air tank to the air spring and discharges the air from the air spring to the atmosphere, and an electric circuit for turning on and off the electromagnetic valve. The electric circuit includes a parking brake switch that is turned on when the parking brake is operated (when the parking lever is pulled), a neutral detection switch that is turned on when the gear position is at the neutral position, and a normally open switch. A first relay that closes when the parking brake switch is on and is self-holding even after the parking brake switch is off and is released from self-holding when the neutral switch is on, and a second relay that is normally open and opens when the neutral switch is on. And the first and second
When the relay is closed, the solenoid valve is turned on to supply air from the air tank to the air spring. FIG. 4 is a plan view of a main part of a vehicle equipped with a start assist device embodying the present invention, and FIG. 5 is a configuration diagram of a trunnion type suspension equipped with the start assist device of the present invention. FIG. 6 is a front view of the drive shaft portion. The vehicle has frames 10 disposed on the left and right sides of the vehicle body, and supports a drive shaft 200 and a driven shaft 300 via a trunnion type suspension. A propeller shaft 60 connected to an engine and a transmission disposed at the front of the vehicle transmits power to a differential gear mechanism provided in a differential gear case 70 integrated with the drive shaft 200. The trunnion type suspension includes a trunnion bracket 110 fixed to the lower surface of the frame 10.
And a central portion of the leaf spring 130 is supported on a trunnion shaft rotatably attached to the trunnion bracket 110. The drive shaft 200 has a drive shaft rotatably disposed in a cylindrical casing 210, and drive shaft tires 250 are attached to both ends of the drive shaft. Generally, two drive shaft tires 250 are mounted on each side, that is, four in total.
A sliding sheet 220 is provided above the housing 210 of the drive shaft 200 and receives one end of the leaf spring 130. The leaf spring 130 generates a spring force that presses the drive shaft 200 toward the road surface. A spring retainer 230 is provided outside the sliding sheet 220. [0008] A first torque rod is attached to the lower portion of the housing 210 of the drive shaft via a bracket. This first torque rod is a trunnion bracket 1
It is connected to the second torque rod via a connecting member penetrating 10. The driven shaft 300 does not transmit the driving force, and rotatably supports the driven shaft tire 350. Driven shaft tire 3
The 50 is generally equipped with two on each side and four on each side, but it is also possible to provide one for each side. The center portion of the drive shaft housing 210 projects vertically to accommodate the differential gear case 70. A bracket 2 is provided on the top of the upper protrusion.
60 is provided and the third torque rod is connected. Since the trunnion type suspension is configured as described above, by selecting the distance between the center of the trunnion shaft and the center of the drive shaft 200 and the distance between the center of the trunnion shaft and the center of the driven shaft 300, the load applied to both shafts Can be selected. The drive shaft 200 and the driven shaft 3
00 makes a circular motion with radii R ₁ and R ₂ , and the distance between the axes changes between D and D 1. The start assist device to which the present invention is applied is disposed above the drive shaft 200. The starting assist device generally denoted by reference numeral 500 includes an air spring 505 and a mounting structure thereof. The air spring 505 includes a diaphragm 510 and a piston member 520 disposed below the diaphragm 510.
And an upper plate 530 disposed above the diaphragm 510. The lower part of the diaphragm 510 is attached to a bracket on the drive shaft side. Diaphragm 510
The upper part is attached to the bracket on the frame side. The frame 10 of the vehicle uses, for example, a channel material having a U-shaped cross section, and a mounting member 570 of a bracket on the frame side is fixed inside the frame. A bracket 560 whose lower side is open is provided integrally with the mounting member 570, and the upper plate 530 of the air spring 505 is housed and fixed in the bracket 560. The air supply port 540 of the air spring 505 penetrates the bracket 560 and protrudes upward. The air supply port 540 is connected to a supply source of compressed air via an air supply pipe described later. Heavy vehicles are equipped with air compressors and high pressure tanks to assist with clutches and brakes and can use this compressed air supply. When the compressed air is not sent into the air spring 505, the drive shaft 200 and the driven shaft 300 are given an axial load at the same ratio as that of a normal trunnion type suspension. When compressed air is sent to the air spring 505, the diaphragm 510 expands,
The drive shaft 200 is urged toward the road surface. Due to this urging force, the contact pressure applied to the drive shaft tire 250 increases, and the propulsive force generated between the tire and the road surface also increases. Therefore, when the vehicle which requires a large propulsion force starts, for example, by starting the start assist device, a smooth start can be achieved. The air spring, which is a component of the start-up assist device, is particularly susceptible to damage because the diaphragm portion is made of a flexible material. Therefore, the air spring is disposed inside the frame of the vehicle, and is further protected by covering with a bracket. In the trunnion type suspension, the housing rotates around the center line of the axle due to the vertical movement of the axle. Although the rotation causes a displacement between the upper support portion of the air spring and each support portion, the influence of the displacement can be minimized by disposing the air spring above the housing of the drive shaft. FIG. 1 is an explanatory diagram showing a system configuration of a vehicle start assist device according to the present invention, FIG. 2 is an explanatory diagram of the operation of a solenoid valve,
FIG. 3 is a control circuit diagram. The vehicle start assist device includes an air tank 830, an electromagnetic valve 850, and an air spring 505 provided on a drive shaft, and is connected by pipes 832 and 855.
The solenoid valve 850 is a three-way valve, and has a port 1 connected to a pipe 832 communicating with the air tank 830 and a port 2 connected to a pipe 855 communicating with the air spring 505.
And a port 3 opened to the atmosphere. FIG. 2 shows the operation of the solenoid valve 850.
When the solenoid valve 850 is off, the port 2 and the port 3 are connected, and when the solenoid valve 850 is on, the port 1 and the port 2 are connected. FIG. 3 shows a configuration of an electric circuit 800, in which a first relay 810 connected in series with a solenoid valve 850 and a second relay 810 are connected.
It has a relay 820. The first relay 810 is a normally open relay, and is connected to the parking brake switch 860. The parking brake switch 860 is a switch that is turned on when the parking brake lever is pulled. When the parking brake lever is pulled, the switch is turned on, energizes the coil 812 of the first relay 810, and closes the contact 814. Parking brake switch 86
When 0 is turned on, the lamp 862 is also turned on to indicate that the parking brake is operating. The second relay 820 is connected to the neutral detection switch 870. Neutral detection switch 8
Reference numeral 70 denotes a switch that is turned on only when the transmission is in the neutral position, and is provided in a sub-star switch circuit for starting the engine from outside the vehicle in a state where the cab is tilted for vehicle inspection or the like. If a switch provided to prevent the vehicle from starting when the engine is started is used, it is not necessary to newly install a neutral switch. The second relay 820 is a normally closed relay, and when the switch 870 is turned on, the coil 82
2 to open contact 824. Next, the operation of the present invention will be described. When the vehicle is stopped, the parking lever is pulled, and the transmission is in the neutral position. Therefore, the parking switch 860 is turned on and the contact 814 of the first relay 810 is closed. Further, since the neutral switch 870 is turned on, the contact 824 of the second relay 820 is opened. Therefore,
The solenoid valve 850 is turned off, and the air spring 505 is opened to the atmosphere. When the vehicle starts, the transmission is operated from the neutral position to the start position. Thereby, the switch 8
70 is open and contact 824 of second relay 820 is closed.
Therefore, the solenoid valve 850 is turned on, and the air tank 8
The air from 30 is sent to the air spring 50, and the contact pressure of the drive shaft tire increases. Next, when the parking brake lever is released, the parking switch 860 is turned off, but the coil 812 of the first relay 810 is energized and self-holding, so that the solenoid valve 850 remains on. When the vehicle starts and an operation such as a gear shift-up is performed, the vehicle passes through the neutral position.
0 turns on, the contact 824 of the second relay 820 opens, and the contact 814 of the first relay 810 also opens. Therefore, the solenoid valve 850 is turned off, and the start assist device 500 is inoperative. When the gear change is completed and the neutral switch 870 is turned off and the contact of the second relay 820 is closed, the contact of the first relay 810 remains open and the solenoid valve 850 remains off. As described above, when the parking brake lever is pulled and the shift position is other than the neutral position,
That is, the start assist device operates only when the vehicle starts. Thereafter, even when the parking brake lever is lowered, the air of the air spring is held, and the contact pressure of the drive shaft tire is kept high. Once the vehicle has started, the auxiliary device is no longer needed, so the gear change actively exhausts the air from the air spring to protect the air spring. As described above, according to the present invention, one of the two rear shafts is used as a drive shaft, and an air spring is provided on the drive shaft to operate the air spring when the vehicle starts moving. In vehicles equipped with a start-up assist device that increases the contact pressure, the vehicle automatically starts with the normal operation at the start by simply diverting existing switches without setting a dedicated controller or operation switch When the auxiliary device is operated, and the vehicle has started and the speed is increased, the operation is automatically released by a shift-up operation. The start gear stage can be operated at any stage including the reverse. After starting, the air spring is evacuated of air to improve the durability of the air spring.

[Brief description of the drawings] FIG. 1 is an explanatory diagram showing a configuration of the present invention. FIG. 2 is an explanatory view showing the action of the electromagnetic wave of the present invention. FIG. 3 is an explanatory diagram showing a control circuit of the present invention. FIG. 4 is a plan view of a vehicle equipped with a start assistance device. FIG. 5 is a side view of FIG. 4; FIG. 6 is a front view of a drive shaft. [Explanation of symbols] 200 drive shaft 210 Drive shaft housing 300 driven shaft 310 driven shaft housing 500 Start assistance device 505 air spring 510 diaphragm 520 piston 530 Top plate 540 compressed air supply port 550 Drive shaft side bracket 560 Frame side bracket 570 Mounting member 800 control circuit 810 First relay 820 second relay 850 Solenoid valve 860 parking switch 870 Neutral switch

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-7-156624 (JP, A) JP-A-7-69033 (JP, A) JP-A 8-156560 (JP, A) JP-A 8- 113023 (JP, A) JP-A-8-48126 (JP, A) JP-A-58-164808 (JP, U) JP-B-1-341164 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60G 5/00 B60G 17/015

Claims (1)

(57) [Claim 1] In a vehicle having two rear axes, one of the rear two axes is a drive axis, and the other one is a driven axis. An air spring that increases the installation pressure; an air tank that supplies air to the air spring; and an air pipe that connects the air spring and the air tank.Supply air is supplied to the air spring and air from the air spring is supplied to the atmosphere. It has a solenoid valve that discharges, an electric circuit that turns the solenoid valve on and off, and the electric circuit is a parking brake switch that turns on when the parking brake is activated (pulling the parking lever), and a neutral gear position. And a neutral detection switch that turns on when it detects that the parking brake switch is on when it is normally open.
A first relay that is self-held even after the parking brake switch is turned off and is released from self-holding when the neutral switch is turned on, and a second relay that is normally opened and opened when the neutral switch is turned on, 2. A starting assistance device for a vehicle, wherein when a relay is closed, an electromagnetic valve is turned on to supply air from an air tank to an air spring.