JPH02197470A - Mounting device for cab - Google Patents

Abstract

PURPOSE:To improve a suppressing effect of pitching by interposing between a car body frame and a cab a hydraulic stabilizer suppressing the pitching of the cab and communicating with an accumulator connected to a surge tank through an opening and closing valve. CONSTITUTION:In the case of a truck mounting to a front end part of a frame 10 constituting a body of the truck a cab 11 through a cab suspension device consisting of front and rear suspension springs 12, 13, a hydraulic stabilizer, comprising front and rear hydraulic cylinders 15, 16, is interposed between the body frame 10 and the cab 11. The front and rear hydraulic cylinders 15, 16 are connected in such a manner that a chamber mutually in an opposite side for a piston communicates by communication pipes 19, 20. And the communication pipes 19, 20 are respectively connected to accumulators 21, 22 each communicating with surge tanks 25, 26 through solenoid valves 23, 24 each controlled opening and closing in accordance with the vehicle condition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application 1] The present invention relates to a cab suspension device, and more particularly, to a device in which a cab is mounted on a vehicle body frame via a cab suspension device. General! 11 A hydraulic stabilizer is interposed between the cab supported via a suspension device and the vehicle body frame to suppress pitching or rolling of the cab, and an accumulator is installed in the hydraulic cylinder constituting the hydraulic stabilizer. In addition, a surge tank is attached to this accumulator via an on-off valve, and by closing the on-off valve depending on the vehicle condition, pitching or rolling of the cab is prevented. [Prior Art] In general, a truck has a cab attached to the tip of its body frame, and a hard spring that can withstand high loads is used as a suspension spring for suspending the axle. Therefore, if the cab is mounted directly on the frame, the image will be transmitted to the cab through the suspension spring and the frame, resulting in poor ride comfort.Therefore, the cab is mounted on the frame via the suspension spring. The cab suspension spring absorbs vibrations and improves riding comfort. Problem 1 to be solved by the K invention: However, in the cab suspension device, the distance between the front and rear suspension springs is large. Although it is short, the center of gravity is high, and the stroke of the suspension spring is also smaller than that of a passenger car.Therefore, it is prone to pitching when the vehicle suddenly starts or brakes, and rolling when the vehicle turns. The pitching and rolling caused the suspension spring to hit the stroke and cause bottoming, which worsened the ride comfort of the cab.In order to improve the ride comfort caused by such pitching and rolling, Consideration has been given to increasing the spring constant and damping force of the cab suspension springs to reduce the movement of the cab.However, such measures limit the effectiveness of the cab suspension device and may worsen ride comfort. Improvements by suspension geometry such as anti-nose dive geometry and anti-roll geometry are also being considered, but they are subject to installation constraints.Therefore, it is not possible to design according to theory, and such measures are fundamental. It will not be a significant improvement. Additionally, in order to suppress pitching and rolling of the cab, it may be possible to install a stabilizer made of a torsion rod between the cab and the frame, but such a stabilizer would limit the effectiveness of the cab suspension device. This may worsen the ride comfort of the cab, which should be improved. That is, if a stabilizer is provided to suppress pitching or rolling, there is a possibility that the riding comfort of the cab will not be improved. The present invention has been made in view of these problems, and provides a cab suspension that prevents pitching or O-ring of the cab without impairing the good riding comfort of the cab due to the cab suspension spring. The purpose is to provide a device. The present invention provides a vehicle in which a cab is mounted on a body frame via a cab suspension device, in which a hydraulic stabilizer for suppressing pitching or rolling of the cab is interposed between the body frame and the cab. In addition, a hydraulic cylinder constituting the hydraulic stabilizer is communicated with a seventh accumulator, and a surge tank is attached to the accumulator via an on-off valve, and opening and opening of the on-off valve is controlled according to the state of the vehicle. This is what I did. 1 Effect 1 Therefore, when a situation is reached where pitching or rolling is predicted to occur, the hydraulic stabilizer will generate a high resistance force by closing the above-mentioned on-off valve, thereby suppressing pitching or rolling of the cab. It turns out. ``Means for Solving the Problems'' Embodiment 1 FIG. 1 shows a cab suspension device according to a first embodiment of the present invention. The cab 11 is mounted on the body frame 10. The cab 11 is not directly attached to the frame 10, but is attached via a cab suspension device consisting of front and rear suspension springs 12 and 13. A hydraulic stabilizer consisting of front and rear hydraulic cylinders 15 and 16 is interposed between the frame 10 and the cab 11.
The piston rod 17 is connected to the frame of the cab 11. Further, the rear hydraulic cylinder 16 is attached to the frame 10, and its piston rod 18 is connected to the indented end of the cab 11. The front and rear hydraulic cylinders 15.16 communicate with each other through a pipe 19.2.
0 communicates the chambers on opposite sides of the piston. Moreover, these communication pipes 1
Accumulators 21, 22 are connected to 9, 20, respectively. Accumulators 21 and 22 are electromagnetic valves 2
3.24 to communicate with a surge tank 25.26. Above accumulator 21.22 and surge tank 25.2
The opening and closing of the electromagnetic valves 23 and 24 connected between the two terminals 6 and 6 are controlled by a microcomputer 27. Connected to the input side of the microcomputer 27 are a brake sensor 29 that detects depression of the brake pedal 28, an accelerator sensor 31 that detects depression of the accelerator pedal 30, and a shift position sensor 33 that detects the shift position of the transmission 32. There is. Furthermore, an acceleration sensor 34 for detecting acceleration of the cab 11 in the longitudinal direction is connected to the microcomputer 27. In the above configuration, when the front end of the cab 11 performs a pitching motion so as to sink, the piston of the front hydraulic cylinder 15 moves downward, so that the oil in the lower chamber of the hydraulic cylinder 15 passes through the communication pipe 19. is supplied to the upper chamber of the rear hydraulic cylinder 16, which causes the hydraulic cylinder 16 to connect to the cab 11.
This will pull the rear part of the This prevents the front end of the cab 11 from pitching downward. When a force is generated that moves the rear of the cab 11 downward, the piston of the rear hydraulic cylinder 16 moves downward,
Oil is supplied to the upper chamber of the front hydraulic cylinder 15 through the communication pipe 20. Therefore, this causes the front end of the cab 11 to be pulled downward. In this way, the hydraulic stabilizer consisting of the pair of hydraulic cylinders 15 and 16 suppresses pitching of the cab 11. Therefore, it becomes possible to improve the deterioration in riding comfort caused by bottoming. Since the cab suspension device is suspended on the chassis frame 10, the movement of the cab 11 roughly becomes a plane vibration relative to the frame 10. And the random input from the four-point spring 12.13 is
Less compared to chassis suspension. Furthermore, regarding the pitching direction component, due to the truck's long wheelbase and large vehicle weight, the input from the unsprung area is small and the vibration period is long. For this reason, even if the suspension has a high spring constant only in the pitching direction, the ride comfort will not deteriorate that much, and in fact it will lead to an improvement in ride comfort in that a smaller stroke can be secured for the simple vertical component. Become. A hydraulic stabilizer consisting of front and rear hydraulic cylinders 15,16 prevents pitching of the cab 11. However, in response to slight pitching from the bottom of the front and rear suspension springs 12.13 and random inputs to the four points supported by the springs 12.13, the above hydraulic stabilizer increases the spring constant. It acts like this. Therefore, the provision of the hydraulic stabilizer deteriorates the riding comfort of the cab. In order to prevent such a situation, the hydraulic stabilizer according to the present embodiment is designed so that the spring constant can be changed by making the amount of air in the attached accumulators 21 and 22 variable, which clearly prevents pitching. When a driving operation is performed that causes the hydraulic stabilizer to increase in spring constant, the spring constant of the hydraulic stabilizer is switched to a higher value. The microcomputer 27 detects the brake pedal 28 or the accelerator pedal 3 by sensors 29 and 31, respectively.
It is designed to detect 0 depression. Also cab 11
The acceleration sensor 34 detects the acceleration in the pitching direction. In general, the shift position of the transmission 32 is detected by a shift position sensor 33. Based on these detections, the microcomputer 27 predicts pitching. For example, the shift position of the transmission 32 detected by the shift position sensor 33 is 1 to 3.
When the accelerator sensor 31 detects that the accelerator pedal 30 has been depressed at the accelerator speed, pitching of the cab 11 due to start or acceleration is predicted. Further, when the brake sensor 29 detects depression of the brake pedal 28, the microcomputer 27 predicts pitching of the cab 11 due to braking. When pitching of the cab 11 is predicted to occur in this manner, the microcomputer 27 supplies control signals to the electromagnetic pulps 23 and 24 to close these valves 23 and 24. Therefore, the accumulator 21.22 and the surge tank 25.26 are respectively blocked, the effective air volume of the accumulator 21.22 is reduced and the spring constant of the hydraulic stabilizer is increased. This causes the hydraulic stabilizer to generate a high resistance force and prevent the cab 11 from pitching. Moreover, since the electromagnetic pulps 23, 24 are normally open, the effective air volume of the 7-cumulator 21, 22 is increased by the surge tank 25, 26, and the hydraulic stabilizer no longer generates a large resistance force. This makes it possible to prevent deterioration in ride comfort. In other words, cab 1 is normally turned on only when necessary, without compromising ride comfort.
It becomes possible to suppress the pitching of 1. Next, a second embodiment will be explained with reference to FIG. In this embodiment, hydraulic cylinders 15 and 16 constituting a hydraulic stabilizer are arranged on the left and right sides. The hydraulic cylinder 15 is attached to the right frame, and its piston rod 17 is connected to the right part of the cab 11. Further, the hydraulic cylinder 16 is attached to the left frame, and its piston rod 18 is attached to the left side portion of the cab 11. Also accumulator 21.22 and surge tank 25.2
The microcomputer 27 that controls the electromagnetic pulps 23 and 24 connected between the 6 and 6 includes a steering sensor 38 that detects the operating angle of the steering handle 37, an acceleration sensor 39 that detects the lateral acceleration of the cab 11, and a transmission 32. They are each connected to a vehicle speed sensor 40 that detects the vehicle speed from the rotation speed on the output side. In the above configuration, the microcomputer 27
The rolling of the cab 11 is predicted by the steering sensor 38, the lateral acceleration sensor 39, or the vehicle speed sensor 40. Based on this prediction, electromagnetic pulp 23.
24, the electromagnetic pulp 23.24
Close. Therefore, this causes the accumulator 21.2
2 effective air volume is reduced, and the left and right hydraulic cylinders 15.1
The spring constant of the hydraulic stabilizer consisting of 6 is increased. This suppresses the lateral movement, or rolling, of the cab 11. Furthermore, in this embodiment as well, since the solenoid valves 23 and 24 are normally open, the riding comfort of the cab 11 is not impaired by the hydraulic stabilizer. Therefore, the cab 11 can maintain good riding comfort by the front and rear suspension springs. K Application Example 1 Although the present invention has been described above with reference to the illustrated embodiments, the present invention is not limited to the above embodiments, and various modifications can be made based on the technical idea of the present invention. For example, in the above two embodiments, switches may be used instead of the various sensors connected to the CPU 27. Further, instead of the CPtJ27, a logic circuit or a sequence circuit may be used. In addition, the first embodiment and the second embodiment
A cab suspension device may be constructed by combining the above embodiments to achieve the respective effects. 1. Effects of the Invention As described above, the present invention provides a hydraulic stabilizer for suppressing pitching or rolling of the cab between the vehicle body frame and the cab, and communicates the hydraulic cylinder constituting the hydraulic stabilizer with an accumulator. Moreover, a surge tank is attached to the accumulator via an on-off valve, and the opening and closing of the on-off valve is controlled according to the state of the vehicle. Therefore, by closing the on-off valve when it is predicted that the vehicle will pitch or roll, the hydraulic stabilizer will generate a high resistance force, thereby making it possible to prevent the cab from pitching or rolling. Become. Moreover, by normally keeping the on-off valve open, it is possible to reduce the resistance of the hydraulic stabilizer and prevent the effect of the cab suspension system from being impaired.

[Brief explanation of the drawing]

FIG. 1 is a piping diagram of a cab suspension device according to a first embodiment of the present invention, and FIG. 2 is a piping diagram of a cab suspension device according to a second embodiment of the invention. The names of the main parts in the drawings are as follows. 10... Body frame 11... Φ... Cab 12.13... φ Suspension spring 15.16... Hydraulic cylinder 19.20... Communication pipe 21. 23. 25. 27 ・・Accumulator・Solenoid valve・Surge tank・Microcomputer

Claims (1)

[Claims] 1. In a vehicle in which a cab is mounted on a body frame via a cab suspension device, a hydraulic stabilizer for suppressing pitching of the cab is interposed between the body frame and the cab. At the same time, a hydraulic cylinder constituting the hydraulic stabilizer is communicated with an accumulator, and a surge tank is attached to the accumulator via an on-off valve, and opening/closing of the on-off valve is controlled according to the state of the vehicle. A cab mounting device featuring: 2. In a vehicle in which a cab is mounted on a body frame via a cab suspension device, a hydraulic stabilizer for suppressing rolling of the cab is interposed between the body frame and the cab, and the hydraulic stabilizer A cab characterized in that a hydraulic cylinder constituting a stabilizer is communicated with an accumulator, and a surge tank is attached to the accumulator via an on-off valve, and opening and closing of the on-off valve is controlled according to the state of the vehicle. Bodywork equipment.