JPH02197472A - Mounting device for cab - Google Patents

Abstract

PURPOSE:To improve a suppressing effect of pitching by providing a pair of hydraulic cylinders parallelly with suspension springs and mutually opposite and equal side chambers of these hydraulic cylinders communicating by a pipe line respectively providing a throttle. 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 17, 23, hydraulic cylinders 18, 24 are provided in parallel to each suspension spring 17, 23 between the body frame 10 and the cab 11. Chambers mutually in an opposite side to a piston of each hydraulic cylinder 18, 24 are connected communicating by the first and second communication pipes 26, 27 respectively providing halfway throttles 31, 32. While these paired communication pipes 26, 27 are connected communicating by a communication pipe 28 providing similarly a throttle 33 and connecting chambers in an equal side of each hydraulic cylinder 18, 24.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a cab mounting system, and more particularly to a system for mounting a cab on a vehicle body frame via a cab suspension system. 1. Summary of the Invention Hydraulic cylinders are provided in parallel to the springs constituting the cab suspension device, and chambers on opposite sides of the front and rear or left and right hydraulic cylinders are communicated through a conduit having a restriction, and the damping force is reduced by the restriction. The hydraulic cylinder is made to act as a shock absorber by generating the pressure, and the chambers on the same side of the front and rear or left and right hydraulic cylinders are made to communicate with each other through a third pipe line, and this pipe line is also provided with a restriction. Furthermore, this throttle is made variable so that it can be adjusted as necessary, and the pitching or rolling of the cab is suppressed by the resistance force generated by this throttle. ``Prior Art'' In general, a truck has a cab mounted on the front end of its body frame.Then, a hard spring that can withstand high loads is used as a suspension spring for suspending the axle. If the cab is mounted directly on the frame, the image will be transmitted to the cab through the suspension spring and the frame, making the ride uncomfortable.Therefore, the cab is mounted on the frame via the suspension spring. The cab suspension spring absorbs the vibrations and improves ride comfort.

[Problems to be solved by the invention]

However, in a cab suspension system, the center of gravity is high despite the short distance between the front and rear suspension springs, and the stroke of the suspension springs is also smaller than that of a passenger car. Therefore, pitching tends to occur when the vehicle suddenly starts or brakes, and rolling occurs when the vehicle turns. Such pitching and rolling can affect the stroke of the suspension spring, causing bottoming, which worsens the ride comfort of the cab. In order to improve the deterioration in riding comfort caused by such pitching and rolling, it is considered to increase the spring constant and damping force of the cab suspension spring to reduce the movement of the cab. However, such measures limit the effectiveness of the cab suspension device, leading to deterioration in ride comfort. Improvements through suspension geometry such as anti-nose dive geometry and anti-roll geometry are also being considered, but these would be subject to mounting restrictions. Therefore, it is not possible to design according to theory, and such countermeasures do not lead to fundamental improvements. Further, rolling caused by wobbling of the cab can be prevented by interposing a stabilizer made of a torsion rod between the cab and the frame. However, the tone 3 rod has a relatively large weight and increases cost. Stabilizers also have the disadvantage of creating space constraints. Further, in a mechanism for suppressing rolling, it is desirable that the damping force can be set separately only in the direction of inclination of the cab. However, such characteristics cannot be imparted to a stabilizer made of a torsion rod. The present invention has been made in view of these problems, and provides a cab mounting device that suppresses pitching and rolling of the cab relative to the vehicle body without using a stabilizer consisting of a torsion rod. The purpose is to

[Means to solve the problem]

The present invention provides a vehicle in which a cab is mounted on a vehicle body frame via a cab suspension device, in which hydraulic cylinders are provided in parallel to the springs constituting the cab suspension 8M, and the hydraulic cylinders on the front and rear or left and right sides The chambers on opposite sides of the piston are communicated by first and second pipes, and a throttle is provided in each of these pipes so that damping force is obtained by the throttle, and the front and rear or left and right The chambers on the same side with respect to the piston of the hydraulic cylinder are communicated by a third pipe line, and the third pipe line is also provided with a restriction, and the restriction is made variable so that it can be adjusted as necessary. This is what I did.

[Operation 1] Accordingly, the hydraulic cylinder functions as a shock absorber due to the throttles provided in the first and second pipes, thereby damping the vibrations of the cab. Moreover, since the throttle provided in the third conduit suppresses the movement of the front and rear or left and right hydraulic cylinders in opposite phases,
This suppresses pitching or rolling of the cab relative to the frame. Embodiment] FIGS. 1 and 2 show a cab mounting device according to a first embodiment of the present invention, in which a cab 11 is tiltably mounted on the front end side of a truck body frame 10. It is mounted. That is, a hinge bracket 12 is attached to the front end of the left and right frames as shown in FIG. installed. A tilt bracket 16 is attached to the link lever 14 via a pin 15, and the cab 11 is supported by this bracket 16. The front end of the cab 11 is supported by a suspension spring 17 on the link lever 14. Further, a hydraulic cylinder 18 is interposed in parallel with the suspension spring 17, as shown in FIG. Hydraulic cylinder 1
8 is attached to the front end portions of the left and right frames 10, and its piston rod 19 is connected to the lower surface of the front end side of the cab 11. On the other hand, a floating bar 20 is attached to the rear end of the cab 11 as shown in FIG. It is supported by a suspension spring 23. A rear hydraulic cylinder 24 is arranged in parallel with this suspension spring 23. The hydraulic cylinder 24 is connected to the rear arch 21 or the frame 10, and its piston rod 25 is connected to the rear end side of the cab 11. Chambers on opposite sides of the pistons of the front and rear hydraulic cylinders 18, 24 are communicated with each other by a first communication pipe 26 and a second communication pipe 27 shown in FIG. A third communication pipe 28 is connected between the pair of communication pipes 26 and 27. That is, the communication pipe 28 communicates the chambers on the same side with the pistons of the front and rear hydraulic cylinders 18, 24. In addition, these three communication pipes 26, 27, and 28 are provided with respective pipes 31, 32, and 33 attached thereto. In the above configuration, vibrations on the frame 10 side are absorbed by the suspension springs 17 and 23, making it difficult for the vibrations to be transmitted to the cab 11. Moreover, the vibrations of the cab 11 are absorbed by the action of the front and rear hydraulic cylinders 18,24. When the cab 11 tries to cause vibration with respect to the frame 10, the hydraulic cylinder 1
8.24 will expand and contract in the same phase with each other. In this case, therefore, oil must flow through the respective lines 26 and 27. At this time, these pipe lines 26.
Since the throttles 31 and 32 provided in each of the cabs 27 serve as resistance, vibrations in the front and back of the cab 11 are suppressed. That is, the hydraulic cylinders 18, 24 function as shock absorbers due to the throttles 31, 32. On the other hand, if the cab 11 pitches forward or backward, the front and rear hydraulic cylinders 18.24
will expand and contract in opposite phases to each other. Therefore, in this case, it is necessary to cause oil to flow in chambers on the same side of the pistons of the front and rear hydraulic cylinders 18, 24. That is, the oil must flow within the third communication pipe 28, and at this time, the third restrictor 33 provided in the communication pipe 28 generates a resistance force. This resistance force prevents the front and rear hydraulic cylinders 18 and 24 from expanding and contracting in opposite phases to each other, thereby causing the cab 1
1 pitching will be prevented. 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 is roughly a planar motion with respect to the frame 10. And the random input from the four-point spring 17.23 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 improve the ride comfort in that a small amount of stroke can be secured for the simple vertical component. It will be connected. In this way, in the cab suspension device according to this embodiment, the shock absorber is connected to the hydraulic cylinder 18.2.
4 and replace these hydraulic cylinders with pipe 2.
6.27, the pipes are arranged in an X-shape, and throttles 31 and 32 are provided at predetermined positions, thereby providing the function of a shock absorber. Further, a third pipe line 28 is connected to the pair of pipe lines 26, 27111, and a throttle 33 is connected to this pipe line 28. Therefore, this diaphragm 33 has an additional function of suppressing pitching. Furthermore, it becomes possible to set the damping force in the vertical direction and the damping force in the pitching direction separately. In addition, pitching is suppressed by the hydraulic cylinders 18, 24 which also serve as shock absorbers. Next, a mounting device according to a second embodiment will be explained with reference to FIGS. 3 and 4. In this embodiment, the third aperture 33 is made variable and the first aperture can be adjusted, and an actuator 35 is attached to the variable aperture 33. And the actuator 35 is connected to the microcomputer 36.
I try to control it with. microcomputer 36
On the input side, there are an accelerator sensor 38 that detects the amount of depression of the accelerator pedal 37, a brake sensor 40 that detects the amount of depression of the brake pedal 39, an acceleration sensor 41 that detects longitudinal acceleration, and a shift position of the transmission 42. Shift position sensors 41 are connected to each. In this way, the cab suspension device of this embodiment is
The throttle 33 provided in the third conduit 28 is made variable by an actuator 35, and the three throttles 31 to 33 are normally operated in a steady running state such as a straight-line running state or a constant speed running state. Set the damping force to provide the most comfortable ride. Only when there is a possibility of pitching occurring, the microcomputer 36 and actuator 35 switch the damping force 33 to reduce the orifice diameter and increase the damping force. When the brake sensor 40 detects that the brake pedal 39 has been depressed, the microcomputer 36 predicts that the cab 11 will pitch forward. Further, when the accelerator sensor 38 detects that the accelerator pedal 37 is depressed while the shift position sensor 43 detects that the shift position of the transmission 42 is between 1st and 3rd gears, the cab 11 The microcomputer 36 predicts that the vehicle will roll backwards. In such a case, the microcomputer 36 supplies a control signal to the actuator 35 to reduce the orifice diameter of the throttle 33 provided in the third communication pipe 28 and increase the damping force. When the damping force of the pitch 33 increases, the damping force increases only in the pitching direction, making it possible to reduce the movement of the cab 11 in this direction. According to such a configuration, it is possible to achieve both ride comfort during steady running and when acceleration is occurring. Next, a third embodiment will be explained with reference to FIG. In this embodiment, hydraulic cylinders 18 and 24 are arranged on the left and right, respectively, and the hydraulic cylinders 18 are attached to the left frame 10, and their piston rods 19 are connected to the lower left side of the cab 11. ing. In addition, the hydraulic cylinder 24 is connected to the right frame 10.
The piston rod 25 is attached to the front end of the
is connected to the lower right side of the cab 11. Moreover, the hydraulic cylinder 18.24 is connected to three communication pipes 26 to 2.
8, and these communication pipes 26~
The apertures 31 to 33 are attached to each of the apertures 28. A steering sensor 46 that detects the turning angle of the steering wheel, a vehicle speed sensor 47, and an acceleration sensor 48 that detects the lateral acceleration of the cab 11 are connected to the microcomputer 36 that controls the actuator 35 that adjusts the aperture amount of the aperture 33. I try to do that. The microcomputer 36 uses the steering sensor 46 and the vehicle speed sensor 47 to predict rolling in which the cab 11 tilts from side to side. Alternatively, the actual rolling of the cab 11 is detected by the lateral acceleration sensor 48. In such a case, the microcomputer 36 supplies a control signal to the actuator 35 to throttle the throttle 33 attached to the third communication pipe 28. Therefore, a high damping force is generated in the throttle 33 against the O-ring, thereby making it possible to prevent the cab 11 from rolling. Therefore, the hydraulic cylinder 18 which also serves as a shock absorber is provided in parallel with the suspension spring.
．． 24 prevents the cab 11 from rolling, making it possible to achieve good riding comfort both during steady running and when rolling is likely to occur. Note that the two embodiments may be combined to form a cab suspension device having a pitching prevention function and a rolling prevention function. ``Effects of the Invention'' As described above, the present invention provides a hydraulic cylinder in parallel with the spring that constitutes the cab suspension device, and connects the first chamber and the chamber opposite to each other with respect to the piston of the front and rear or left and right hydraulic cylinders. In addition to communicating through a second pipe line, each of these pipe lines is provided with a throttle so that damping force is obtained by the throttle, and the chambers on the same side with respect to the pistons of the front and rear or left and right hydraulic cylinders are connected to each other. The pistons are communicated by the third conduit, and the third conduit is also provided with a restriction.Therefore, the chambers on the same side are communicated with the pistons of the front and rear or left and right hydraulic cylinders that also serve as shock absorbers. The pitching or rolling of the cab can be suppressed by the restrictor provided in the third conduit that allows the engine to rotate.Also, by making the restrictor of the third conduit variable and narrowing it to a large extent as necessary, it is possible to suppress pitching or rolling of the cab. , it becomes possible to reliably prevent pitching or rolling without impairing ride comfort during steady driving. 10 ・ ・ ・ ・ 11 ・ ・ ・ ・ 17 ・ ・ ・ ・ 18 ・ ・ −・ 23 ・・ ・ ・ 24 ・ ・ ・ ・ 26 ・ ・ ・ ・ 27 ・ ・ ・ 28 ・ ・ ・ 31~33 ・ 35 ・ ・ ・ ・ ・ Body frame - Cab suspension spring (front) ・ Hydraulic cylinder (front) ・Suspension spring (rear) - Hydraulic cylinder (rear) - First communication pipe - Second communication pipe - Third communication pipe - Throttle - Actuator

[Brief explanation of the drawing]

FIG. 1 is a piping diagram showing a cab mounting device according to a first embodiment of the present invention, FIG. 2 is a perspective view thereof, and FIG. 3 is a perspective view of a cab mounting device according to a second embodiment of the present invention. FIG. 4 is a piping diagram of the same, and FIG. 5 is a piping diagram of the bodywork device of the third embodiment. The names of the main parts in the drawings are as follows.

Claims (1)

[Scope of Claims] 1. In a vehicle in which a cab is mounted on the body frame via a cab suspension device, a hydraulic cylinder is provided in parallel to the spring constituting the cab suspension device, and The chambers on opposite sides of the piston of the hydraulic cylinder are communicated by first and second pipes, and each of these pipes is provided with a throttle, and a damping force is obtained by the throttle, and A cab bodywork characterized in that chambers on the same side of the pistons of the front and rear or left and right hydraulic cylinders are communicated through a third conduit, and the third conduit is also provided with a restriction. Device. 2. The cab frame according to claim 1, wherein the throttle provided in the third conduit is made variable and the throttle is adjusted according to the state of the vehicle. equipment.