JPH0362586B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a tilted cab with a suspension, and particularly to a cab suspended on a suspension.
The present invention relates to a tail cab with a suspension that can maintain a predetermined posture against additional loads caused by passengers riding on the vehicle, cargo loading, etc.

[Technical background of the invention and its problems]

In general, a cab-over type vehicle has an engine covered by a cab, and is therefore equipped with a tailing mechanism for tilting the cab during maintenance or the like. In addition, in recent years, suspension mechanisms have been provided on the vehicle body frame in the vehicle width direction and vehicle length direction, respectively, to suspend the cab and improve ride comfort.

Conventionally, a tail cab having this type of suspension mechanism employs a hydraulic cylinder system as the tail mechanism. Generally speaking, this hydraulic cylinder system connects rods of hydraulic cylinders provided on the vehicle body frame, and tilts the cab by expanding and contracting the rods.

However, in the past, there were the following problems.

Generally, the performance of a suspension mechanism is set by taking into account the weight of the cab and the weight of the driver, so the load distribution changes when cargo is loaded into the cab or passengers other than the driver enter the cab, causing the cab's posture to change. There was a problem that it could not be maintained almost horizontally. In particular, these additional loads tend to be concentrated at the rear of the cab, such as the roof rack and seats, due to the layout of the cab, resulting in an attitude where the rear of the cab sinks and the front lifts up. In such a case, the effectiveness of the rear suspension deteriorates, resulting in a hard ride, and the optical axis of the headlamp is also likely to become misaligned.

Additionally, the hydraulic cylinder type tail mechanism acts as a damper against cab vibrations during driving, which has a negative effect on riding comfort, and has the drawbacks of being heavy and expensive.

Furthermore, due to its complicated structure, it was prone to breakdowns, and in such cases, the cab could no longer be tilted.

[Purpose of the invention]

The present invention was devised in view of the above-mentioned problems, and its purpose is to adopt a torsion bar system as a cab tailing mechanism, which is cost-effective and highly reliable, and to utilize the torsion force of the torsion bar. To provide a tailed cab with a suspension capable of maintaining the cab suspended on the suspension in a substantially horizontal posture against additional loads.

[Embodiments of the invention]

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows the basic configuration of the present invention. Suspension 2 is on the body frame 1...
The cab 4 is suspended by..., 3.... A pair of suspensions 2..., 3... are provided in the vehicle width direction, and suspend the front and rear portions of the cab 4.
Further, this cab 4 employs a tilt mechanism using a torsion bar, and 5 is a torsion bar. As is known, this torsion bar 5 is, in principle, provided on the vehicle body frame 1 and the cab 4 so that both ends are restricted from rotating, and the torsion bar 5 is used to tilt the cab 4 by the torsional force applied when it is locked. It has higher cost merit, reliability, etc. Generally, one end is rotationally restricted and supported by the vehicle body frame 1 side, and the other end is rotatably supported, and a cab support bracket fixedly installed on the torsion bar 5 transmits the weight of the cab to twist the torsion bar 5. , in the present invention, the base end 6b of the torsion bar lever 6 whose extending end 6a is to be brought into contact with the lower surface of the cab 4 is provided at the other rotatable end.
are connected to each other, and the torsion bar 5 is configured to generate a torsion force due to the cab's own weight applied to the lever 6. The extending end 6a of this torsion bar lever 6 is located at the pitching center of the cab 4 (the center of swinging of the cab in the longitudinal direction due to vibrations when the vehicle is running)
It is slidably abutted downward. Further, a link arm 7 for regulating the tail trajectory of the cab 4 is interposed between the cab 4 and the vehicle body frame 1.
Both ends of the link arm 7 are rotatably connected, and the end 7a on the vehicle frame side forms a tail center C. Note that 8 is a roof rack for loading luggage.

Further, it will be explained in detail. 2 and 3 show the peripheral portion of the front suspension 2, which has a symmetrical configuration in the vehicle width direction. A tail bracket 9 is attached to the front end of the vehicle body frame 1.
is provided, and this bracket 9 is connected to the link arm 7.
It rotatably supports the vehicle body frame side end 7a. As shown in the figure, the body frame side end 7a
The body frame side end 7 is branched into two parts so as to sandwich it from the vehicle width direction, and the body frame side end 7 is attached to the bearing cylinder 10 installed on these branch ends 9a through a rubber mount 11.
A is pivotally supported and forms a tail center C. On the other hand, a cab-side bracket 12 is provided on the lower surface of the cab 4 so as to face the vehicle body frame 1 side, and the cab-side end 7b of the link arm 7 is connected behind the tail center C in the same way as the vehicle body frame-side end 7a described above. It is supported by a shaft with a configuration.

The front suspension 2 is mainly composed of a shock absorber 13 and a U-shaped leaf spring 14. Both ends of the shock absorber 13 are rotatably attached between the cab side bracket 12 and the body frame side end 7a of the link arm 7, respectively. Further, the leaf spring 14 has eyelets 14a at both ends thereof.
..., and is placed close to the cab-side bracket 12 and the cab-side end 7b of the link arm 7, where the amount of change is relatively small between the cab 4 and the vehicle body frame 1, which are separated due to vibrations during running. It is rotatably attached to the provided support piece 7c, and has a structure that reduces stress concentration at the spring end and allows use of a spring with a low spring constant, thereby improving riding comfort.

In addition, the link arm 7 is provided with an elastic shock absorbing member facing the cab 4 in order to buffer and control the amount of sinking of the cab 4 due to the suspensions 2..., 3... that buffer and attenuate vibrations during running. 15 and a regulating member 16 are provided. The elastic buffer member 15 is made of a flexible synthetic resin material, etc., and functions to provide a comfortable ride by repelling and suppressing sinking, and the regulating member 16 compresses the elastic buffer member 15 to prevent further sinking. In addition to restraining Cab 4,
This is intended to extend the life of the flexible elastic shock absorbing member 15. Further, the regulating member 16 also eliminates the instability of the cab 4 when it is tilted due to the intervention of the elastic buffer member 15.

Further, the tail bracket 9 supports the torsion bar 5 arranged in the vehicle width direction. One bracket (not shown) supports one end of the torsion bar 5 while restricting its rotation, and the other bracket 9 supports the other end in a rotatable manner. A base end 6b of a torsion bar lever 6 extending toward the rear of the cab 4 is connected to the other rotatable end, as shown by a two-dot chain line in the figure. The extending end 6a of this torsion bar lever 6 is aligned with the pitching center X.
An abutment surface 17a provided on the lower surface of the lower cab 4 is slidably abutted on a pad member 17 formed smoothly. And this torsion bar lever 6 is
It is configured to transmit the torsion force of the torsion bar 5 at the time of tailing and apply a tailing force to the cab 4 while sliding on the contact surface 17a of the pad member 17.
Reference numeral 18 denotes a stabilizer for regulating the roll of the cab 4 in the vehicle width direction, and is rotatably attached to a bracket 19 provided on the vehicle body frame 1, and its ends are attached to link arms 7 on both sides in the vehicle width direction. The shaft portion 18a is connected to the cab side end portion 7b of the vehicle via a link and is configured to restrict the cab roll by twisting the shaft portion 18a extending in the vehicle width direction.

On the other hand, FIGS. 4 and 5 show the periphery of the rear suspension 3. On the vehicle body frame 1, a mounting bracket 20 is extended in the vehicle width direction from a hanging portion 1a facing the lower surface of the cab 4. The rear suspension 3 is mainly composed of a shock absorber 21 and a coil spring 22 supported by the mounting bracket 20. The upper and lower ends of the coil spring 22 are held by spring seats 23 and 24, respectively, and the shock absorber 21 is held by the upper spring seats 2.
3 and the mounting bracket 20. Upper spring catch 23
A cab holder 25 is placed on top. This cab holder 25 is equipped with a cab lock device 26. This locking device 26 consists of a hook 28 which is pivotally supported by the cab 4 and rolled by a rod 27, and an engaging member 29 which is engaged with the hook 28. Further, the shoulder portion 25a of the holder 25 is formed into a tapered shape, and a sliding member 30 made of nylon or the like is adhered to the surface thereof. The sliding members 30 are configured to restrict lateral displacement of the cab 4 together with the tapered shoulders 25a. Further, a cushion material 31 is interposed between the spring seats 23 and 24 to elastically cushion and restrict the sinking of the cab 4.

Note that 32 is a lateral rod for preventing the suspension 3 from falling and displacement in the vehicle width direction due to cab rolls, and both ends of the rod are rotatably attached between the vehicle body frame 1 and the spring seat 23.

By the way, the gist of the present invention based on the above-described specific device example is as shown in FIG. 6a
is brought into contact with the lower surface of the cab 4 at the pitching center X between the front suspension 2 and the rear suspension 3, and the additional load W due to the above-mentioned occupants riding and loading of luggage into the cab 4, roof rack 8, etc. of,
The structure is such that it is supported by the torsional force of the torsion bar 5. Generally suspension 2
The dimensions, performance, etc. of ..., 3... are set by giving the cab's own weight, the driver's weight, etc. as a preset amount, and are designed so that the cab 4 can be suspended in a substantially horizontal state with respect to the set amount. be done. However, in reality, there may be other passengers in cab 4 or roof rack 8.
There are also cases where cargo is loaded into the cab 4, and when such an additional load W is applied, the set state may not necessarily match. In particular, due to the layout of the cab 4, the additional load W tends to be concentrated on the rear side, so that the cab 4 is in a backward-sloping state. Therefore, in the present invention, the torsion bar lever 6, which serves as an arm for transmitting the torsion force of the torsion bar 5 and tilting the cab 4, is extended to the rear side of the cab 4 and brought into contact with the bottom of the pitching center X. The additional load acting on the extending end 6a of the lever 6 is supported by the torsional force of the torsion bar 5.

That is, as shown in the figure, when an additional load W acts, that load tries to twist the torsion bar 5 by ζ° via the torsion bar lever 6. This torsion angle (ζ°) causes a torsion force T=Kζ on the torsion bar 5.
is added (K: spring constant of the torsion bar).
This torsional force T is a force F that pushes up the cab 4 from below around the tail center C as a reaction force for the load.
It acts as Kζ/R (R: distance from the tail center to the contact surface). As a result, a restoring force P of P=FR/L=Kζ/L acts on the rear end of the cab 4 (L: distance from the tail center to the rear end of the cab), and the cab 4 is This means that it can be supported in a substantially horizontal state. This restoring force P increases or decreases in proportion to the load.

Note that under normal load conditions, only the torsion force necessary for the cab tail is generated in the torsion bar 5, and this torsion force is an auxiliary force for the cab tail and is relatively small. It is supported by 2..., 3.... Therefore, the torsional force T generated by the additional load W acts for the first time as a force F to push up the cab 4.

At this time, the extending end 6a of the torsion lever 6
It is conceivable to have the rear suspension 3 extend as far as possible to the rear of the cab 4 and come into contact with it; however, in this case, the spring constant of the rear suspension 3 is set to be relatively small compared to the spring constant of the torsion bar 5 in order to prioritize riding comfort. , the rear suspension 3 becomes ineffective, which adversely affects riding comfort. On the other hand, if the torsion bar is brought into contact with the front of the cab 4, the twist angle of the torsion bar generated by the additional load W is hardly applied, and the torsion bar cannot perform its function. Also pitching center
Actually, the front and rear suspensions 2..., 3...
The vehicle may move back and forth during running depending on the spring constants of the springs 14, 22 and the damping rates of the shock absorbers 13, 21, but in the present invention, they are set at substantially average positions.

In this way, in the present invention, the torsion bar lever 6 for transmitting the torsional force of the torsion bar 5 to tilt the cab 4 is brought into contact with the bottom of the pitting center An additional load W that is easily applied can be transmitted to the torsion bar 5, and a restoring force P can be obtained by the additional torsion force T generated in the torsion bar 5, and the cab 4 can be supported and its attitude can be maintained substantially horizontally. In addition, since the torsion bar lever 6 is brought into contact between the front and rear suspensions 2..., 3..., especially in the vicinity of the pitching center X, the suspension 2
There is no adverse effect on the improvement in riding comfort due to ..., 3.... Furthermore, since the present invention employs a torsion bar system as the tail mechanism, it has high cost benefits, high reliability, and has a simple structure.

〔Effect of the invention〕

In summary, the present invention exhibits the following excellent effects.

(1) The cab can be maintained in a substantially horizontal state against additional loads such as luggage loaded on the cab, and deterioration of riding comfort and misalignment of the optical axis of the headlamp can be prevented.

(2) Since the cab is supported from below the pitching center of the cab, a comfortable ride can be maintained without deteriorating the suspension performance.

(3) Based on a torsion bar type tail mechanism, it can be easily constructed, and has high cost benefits and reliability.

[Brief explanation of drawings]

FIG. 1 is a schematic side view showing a preferred embodiment of the present invention, FIG. 2 is a side view showing the peripheral part of the front suspension adopted in the present invention, and FIG. 3 is a front view of FIG. FIG. 4 is a front view showing the peripheral portion of the rear suspension employed in the present invention, and FIG. 5 is a side view thereof. In the figure, 1 is the body frame, 2 and 3 are the suspension, 4 is the cab, 5 is the torsion bar, 6 is the torsion bar lever, 6a is the extension end which is the other end of the torsion bar lever, and X is the pitching center. .

Claims (1)

[Claims] 1 A torsion system that connects the body frame and the cab with a torsion bar that tilts the cab with its own torsional force, and transmits the torsional force to one end of the torsion bar. A tail cab with a suspension, characterized in that a bar lever is connected and the other end of the lever is positioned at the center of pitching between the suspensions to support the cab.