JP4181458B2 - Cab suspension device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cab suspension device that suspends a cab in a truck or the like.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a cab suspension device for suspending a cab in a truck or the like, a device using an air spring as a spring is known.
In such a cab suspension device using an air spring, for example, as disclosed in Japanese Patent Laid-Open No. 6-72703, the ride comfort can be adjusted by adjusting the volume of the sub tank connected to the air spring.
[0003]
[Patent Document 1]
JP-A-6-72703 [0004]
[Problems to be solved by the invention]
However, as described above, in order to adjust the sub-tank volume connected to the air spring, a sub-tank with a variable volume is required, which causes a problem that the apparatus becomes complicated and expensive.
[0005]
The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a cab suspension device that can easily and surely change a support end spring constant according to the preference of a driver or the like. .
[0006]
[Means for Solving the Problems]
The cab suspension apparatus according to claim 1 is provided between a link member that has a front end portion rotatably connected to a vehicle frame side and a rear end portion rotatably connected to a cab side, and a lower surface of the cab. in cab suspension device formed by arranging the spring, have a position changing means for changing the position of the spring in the longitudinal direction, said position changing means, the position of the spring to move along the spring to the link member as well as changes and a guide rod for guiding the lower end of said spring along said link member, characterized in that the upper end of the spring to have a the adjustment rod that moves along the lower surface of the cab.
[0008]
The cab suspension apparatus according to a second aspect is the cab suspension apparatus according to the first aspect , wherein the position changing means includes an adjustment rod that moves a lower end of the spring along the link member, and an upper end of the spring. And a guide rod for guiding along the lower surface.
A cab suspension apparatus according to a third aspect is the cab suspension apparatus according to the first or second aspect , wherein the adjustment rod is rotatable by a motor.
[0009]
The cab suspension apparatus according to a fourth aspect is the cab suspension apparatus according to any one of the first to third aspects, wherein the spring is an air spring.
[0010]
(Function)
In the cab suspension apparatus according to claim 1, a spring is connected between a link member that has a front end portion rotatably connected to a vehicle frame side and a rear end portion rotatably connected to a cab side, and a lower surface of the cab. Is placed.
[0011]
And the support end spring constant of the cab suspension is changed by changing the position of the spring in the front-rear direction by the position changing means.
The support end spring constant is an actual spring constant for the cab corrected by the link mechanism.
[0012]
Further, the position of the spring is changed by the position changing means by moving the spring along the link member.
When the adjustment rod is rotated, the upper end of the spring is guided by the adjustment rod and moved along the lower surface of the cab, and at the same time, the lower end of the spring is guided by the guide rod and moved along the link member. Be changed.
[0013]
In the cab suspension apparatus according to claim 2 , when the adjustment rod is rotated, the lower end of the spring is guided along the link member by the adjustment rod, and at the same time, the upper end of the spring is guided by the guide rod along the lower surface of the cab. It moves and the position of the spring is changed.
In the cab suspension apparatus according to the third aspect, the spring is moved along the adjustment rod by rotating the adjustment rod by the motor.
[0014]
In the cab suspension apparatus according to the fourth aspect , an air spring is used as the spring.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0016]
FIG. 1 shows the details of the main part of FIG. 2, and FIG. 2 shows an embodiment of the cab suspension device of the present invention.
In FIG. 2, reference numeral 11 indicates a cab of a track.
The cab 11 is disposed above the vehicle body side frame 13 of the truck. The vehicle body frame 13 is suspended by a front cab suspension 15 and a rear cab suspension 17.
[0017]
The rear cab suspension 17 is configured by disposing an air spring 23 between a support member 19 protruding upward from the vehicle body side frame 13 and a main member 21 of the cab 11.
The air spring 23 is fixed to the upper end of the support member 19.
The front-side cab suspension 15 is configured by disposing an air spring 27 between the main member 21 and the link member 25 of the cab 11.
[0018]
The front end portion 25a of the link member 25 is rotatably connected to a vehicle body side bracket 28 that protrudes upward from the vehicle body side frame 13.
Further, the rear end portion 25b of the link member 25 is rotatably connected to a cab side bracket 29 that protrudes downward from the main member 21 of the cab 11. In this embodiment, the air spring 27 disposed between the main member 21 and the link member 25 of the cab 11 is movable in the front-rear direction by the position changing means 31.
[0019]
FIG. 1 shows details of the cab suspension 15 on the front side where the position changing means 31 is arranged.
In this embodiment, the position changing means 31 includes a guide rod 33 that guides the lower end of the air spring 27 along the link member 25, and an adjustment rod 35 that moves the upper end of the air spring 27 along the lower surface of the cab 11. I have.
[0020]
The guide rod 33 is disposed in the front-rear direction along the link member 25, and both ends thereof are fixed to the link member 25.
The adjustment rod 35 is disposed in the front-rear direction along the main member 21 of the cab 11, and both ends thereof are fixed to brackets 37 formed on the main member 21.
The adjustment rod 35 is made of a bolt and has a head portion 35a for rotating the adjustment rod 35 at the front end.
[0021]
The guide rod 33 and the adjustment rod 35 are arranged in parallel.
FIG. 3 shows details of the air spring 27, and an upper mounting portion 41 and a lower mounting portion 43 are arranged above and below the main body portion 39.
A through hole 43a is formed in the lower mounting portion 41, and the guide rod 33 is inserted into the through hole 43a.
[0022]
A screw hole 41a is formed in the upper mounting portion 41, and the adjustment rod 35 is screwed into the screw hole 41a.
In the cab suspension apparatus described above, when the adjustment rod 35 is rotated, the upper mounting portion 41 at the upper end of the air spring 27 is guided by the adjustment rod 35 and moves along the lower surface of the cab 11. The lower attachment portion 43 is guided by the guide rod 33 and moves along the link member 25, and the position of the air spring 27 is changed.
[0023]
Thus, the support end spring constant of the cab suspension 15 can be changed.
That is, when the air spring 27 is moved to the front end portion 25a side of the link member 25, the support end spring constant becomes hard (hard), and when it is moved to the rear end portion 25b side, the support end spring constant is soft (soft). I feel.
[0024]
FIG. 4 schematically shows the link member 25 and the main member 21, and shows a state when a conventional spring such as a coil spring 45 is arranged between the link member 25 and the main member 21.
It is assumed that the load W at the load point A of the main member 21 is balanced with the coil spring 45 located at the lever ratio α.
[0025]
If the spring reaction force of the coil spring 45 is f,
W = αf (1)
When the spring constant of the coil spring 45 is k and the deflection is x,
f = kx (2)
When the displacement (deflection x) of the coil spring 45 is converted into the displacement X at the load point A,
X = (1 / α) x (3)
From Equation (1), Equation (2), and Equation (3),
W = α ² kX (4)
When the spring constant k is converted into a converted spring constant K which is a spring constant at the load point A, from the equation (4),
K = α ² k (5)
It becomes.
[0026]
Therefore, the converted spring constant K at the load point A is proportional to α ² times k.
On the other hand, in the case of the air spring 27, the spring constant is k, the polytropic index is γ, the air spring 27 internal pressure is P, the effective pressure receiving area is A, the air spring 27 internal volume (including the auxiliary tank) is U, the air spring 27 If the load applied to is w,
k = γ (P + 1) · A ² / V
P = w / A
It becomes.
[0027]
Therefore, when the air spring 27 is installed at the position of the lever ratio α,
P ′ = (1 / α) · w / A
= (1 / α) · P
K ′ = γ ((1 / α) · P + 1) · A ² / V
Therefore, the spring constant is approximately 1 / α times.
[0028]
Further, considering the lever ratio α, from the above equation (5),
K = α ² k × (1 / α)
= Αk.
In the above-described cab suspension device, the position change means 31 can change the support spring constant of the cab suspension 15 by changing the position of the air spring 27 in the front-rear direction. Accordingly, the support end spring constant can be easily and reliably changed.
[0029]
In the cab suspension apparatus described above, the position of the air spring 27 is changed by the position changing means 31 by moving the air spring 27 along the link member 25. Therefore, the air spring 27 is moved to an arbitrary position. Can be located.
In the cab suspension apparatus described above, the lower end of the air spring 27 is guided along the link member 25 by the guide rod 33, and at the same time, the upper end of the air spring 27 is guided along the lower surface of the cab 11 by the adjustment rod 35. Therefore, the position of the air spring 27 can be easily and reliably changed by rotating the adjustment rod 35.
[0030]
Moreover, since the air spring 27 is used for the spring, riding comfort can be improved.
In the above-described embodiment, the example in which the air spring 27 is used as the spring has been described. However, the present invention is not limited to this embodiment, and for example, a coil spring or the like may be used.
[0031]
Moreover, although embodiment mentioned above demonstrated the example which has arrange | positioned the guide rod 33 to the link member 25 side, and has arrange | positioned the adjustment rod 35 to the main member 21 side of the cab 11, this invention is limited to this embodiment. Instead of this, an adjustment rod may be arranged on the link member 25 side, and a guide rod may be arranged on the main member 21 side of the cab 11.
[0032]
Furthermore, in the embodiment described above, the adjustment rod 35 may be configured to be rotatable by a motor.
For example, by providing a switch for driving the motor in the cab 11, the position of the air spring 27 can be easily changed from the cab 11.
[0033]
【The invention's effect】
As described above, in the cab suspension apparatus according to the first aspect, it is possible to change the support end spring constant of the cab suspension by changing the position of the spring in the front-rear direction by the position changing means. It is possible to easily and reliably change the support end spring constant according to the preference.
[0034]
Further, since the position of the spring is changed by the position changing means by moving the spring along the link member, the spring can be positioned at an arbitrary position.
In addition, the lower end of the spring is guided along the link member by the guide rod, and at the same time, the upper end of the spring is guided along the lower surface of the cab by the adjustment rod. Can be easily and reliably changed.
[0035]
In the cab suspension device according to the second aspect , the upper end of the spring is guided along the lower surface of the cab by the guide rod, and at the same time, the lower end of the spring is guided along the link member by the adjustment rod. By moving, the position of the spring can be changed easily and reliably.
In the cab suspension apparatus according to the third aspect , since the adjustment rod is made rotatable by the motor, for example, by providing a switch for driving the motor in the cab, the position of the spring can be changed from the cab.
[0036]
In the cab suspension apparatus according to the fourth aspect , since the air spring is used as the spring, riding comfort can be improved.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing details of a position changing unit in FIG. 2;
FIG. 2 is an explanatory view showing an embodiment of a cab suspension device of the present invention.
FIG. 3 is an explanatory view showing details of the air spring of FIG. 1;
FIG. 4 is an explanatory diagram for explaining the operation of the present invention.
[Explanation of symbols]
11 Cab 25 Link member 25a Front end portion 25b Rear end portion 27 Air spring 31 Position changing means 33 Guide rod 35 Adjustment rod

Claims (4)

A cab suspension device in which a spring is disposed between a link member, the front end of which is rotatably connected to the vehicle frame, and the rear end of which is rotatably connected to the cab, and the lower surface of the cab. In
Have a position changing means for changing the position of the spring in the longitudinal direction,
The position changing means changes the position of the spring by moving the spring along the link member,
A guide rod for guiding the lower end of the spring along the link member;
An adjustment rod that moves the upper end of the spring along the lower surface of the cab;
Cab suspension device which is characterized in that have a. The cab suspension device according to claim 1,
The position changing means includes
An adjustment rod that moves the lower end of the spring along the link member;
A guide rod for guiding the upper end of the spring along the lower surface of the cab;
Cab suspension device characterized in that it comprises a. In the cab suspension apparatus according to claim 1 or 2 ,
The cab suspension device is characterized in that the adjustment rod is rotatable by a motor . The cab suspension device according to any one of claims 1 to 3 ,
The cab suspension device is characterized in that the spring is an air spring .

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