JPH0512164B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a vehicle height adjustment device, and more particularly to a vehicle height adjustment device suitable for route buses, trucks, etc. that uses flat leaf springs instead of air springs or coil springs.

BACKGROUND OF THE INVENTION Generally, leaf springs of a vehicle are bent due to changes in the load and unevenness of the road surface, and the height of the vehicle changes.
When the height of a vehicle changes in this way, for example, in the case of a route bus or a truck, if the height of the vehicle when the vehicle is empty, that is, the minimum ground clearance, is set low, the minimum ground clearance becomes more likely to hit the road surface when the vehicle is loaded. , the minimum ground clearance when empty had to be set high. However, increasing the minimum ground clearance when the vehicle is empty deteriorates the ease of getting on and off the vehicle in the case of buses, etc., and in the case of trucks, it not only deteriorates the ease of cargo handling but also deteriorates the stability when driving at high speeds. There is a point. For this reason, it is possible to use air springs that can keep the vehicle height constant regardless of the vehicle's loading status, but since the lateral rigidity of air springs is inherently low, reinforcement parts such as lateral rods, radius rods, and torque rods are required. This increases weight and costs, making it difficult to use for route buses and trucks. In addition, with conventional leaf springs, the support part from the car body is fixed or supported by a support mechanism that allows only circular arc movement within a certain range. It was impossible to make any adjustments.

Furthermore, Japanese Utility Model Application No. 59-43202 discloses a ground clearance adjustment device for a vehicle, but this conventional example has a pair of shackles that support the ends of a leaf spring, and the pair of shackles are connected by a shackle pin. A hydraulic cylinder is connected between them to form a triangular shape, and the hydraulic cylinder is expanded and contracted to change the opening angle of the pair of shackles and move the ends of the leaf springs up and down. Since the vehicle height is changed, maintenance of the vehicle height depends entirely on the hydraulic lock of the hydraulic cylinder, and the load applied to the end of the leaf spring is always acting on the hydraulic cylinder, and the hydraulic Since the lock is incomplete, there is a risk that the height of the vehicle may change unexpectedly while the vehicle is running or stopped, and there is also a risk that the strength of the shaft portion may be reduced.

Further, Japanese Patent Application Laid-Open No. 59-100005 discloses a leaf suspension device, but in this conventional example, a spring bracket supporting the end of a leaf spring is shaped like a cam, and this is rotated to move the vehicle. There are two types: one that adjusts the vehicle height, and one that adjusts the vehicle height by rotating the spring bracket itself, but neither of these have a structure to ensure that the vehicle height is maintained, and these do not allow There was also a risk that the vehicle height would change unexpectedly while the vehicle was stopped.

Purpose The present invention has been made in order to eliminate the drawbacks of the prior art described above, and its purpose is to make the leaf spring support part of the leaf spring support mechanism relative to the vehicle body vertically movable with respect to the vehicle body. The purpose of this invention is to make it possible to adjust the vehicle height of a vehicle that uses only leaf springs with an extremely simple configuration, and to make it possible to adjust the vehicle height of a vehicle using only leaf springs with an extremely simple configuration. The purpose is to make the ground clearance low so that it does not hinder the running of the vehicle when it is loaded. Another objective is to obtain a vehicle height adjustment device that has the same vehicle height adjustment function as an air spring without using an expensive air spring, and thereby achieves cost reduction and weight reduction. It is to be. Another object of the present invention is to provide an operating mechanism for tightening or loosening a fastening element that fastens and fixes a spring bracket to a chassis frame. The actuating mechanism tightens the fastening element to prevent the spring bracket from moving up and down to prevent the vehicle height from changing inadvertently while the vehicle is running or stopped, and when changing the vehicle height, the fastening element By loosening the hydraulic cylinder with an operating mechanism, the load on the hydraulic cylinder is reduced, and the vehicle height can be changed with a small amount of force.

Summary In summary, the present invention is used in a vehicle suspension system in which a support mechanism is provided in a part of a vehicle body and a leaf spring is supported by the support mechanism, and the leaf spring support portion of the support mechanism is connected to the vehicle body. In a vehicle height adjustment device that is provided with a vertically movable support part vertical mechanism, a guide part is provided in the vertical direction on the chassis frame, and a spring bracket that supports the end of a leaf spring is vertically movable in the guide part. A fastening element is provided for attaching the spring bracket to the chassis frame and tightening and fixing the spring bracket to the chassis frame, a vertical operating mechanism for moving the spring bracket up and down, and an operating mechanism for tightening or loosening the fastening element. It is something to do.

Configuration The present invention will be described below based on embodiments shown in the drawings. What is shown in FIGS. 1 and 2 is a reference example of the present invention, and a part of the vehicle body 1, for example, a chassis frame 2, is provided with a support mechanism 3, and the support mechanism 3 allows the leaf spring 4 to be A vehicle suspension system 5 is shown supporting a vehicle. In the suspension device 5,
A support part vertical mechanism 8 is provided in which the leaf spring support part 6 of the support mechanism 3 is configured to be movable up and down with respect to the vehicle body 1. The above basic configuration is also common to the first embodiment of the present invention shown in FIG. 3, the second embodiment of the present invention shown in FIG. 4, and the reference example shown in FIG. 5, so the same parts are used. The same reference numerals are used in the drawings, and some explanations will be omitted.

In the reference example, the support part 6 is the shackle 10.
The support part vertical mechanism 8 is equipped with a shackle length variable mechanism 11 that makes the length of the shackle variable. The leaf spring 4 has a U bolt 12 in the center.
It is tightened and fixed to the axle 14 via the pad 13, and the centerpiece 1 is attached to the uppermost spring plate 15.
5a and 15b are formed, and the centerpiece 15a is a spring bracket 1 fixed to the chassis frame 2.
6 via a spring pin 18.

The variable shaft length mechanism 11 includes a shaft 10 which is pivotally connected via a pin 20 to a spring bracket 19 having an elongated hole 10a and fixed to the chassis frame 2, and is configured to be able to swing integrally with the shaft. A hydraulic cylinder 21 whose base end 21a is pivotally connected to a pin 20, and a spring pin 23 which is pivotally connected to one end of a piston rod 22 of the hydraulic cylinder and slidably accommodated in the elongated hole 10a of the shackle 10, are installed. The eyepiece 15b is pivotally attached to a spring pin 23 of the square piece. Although not shown, the hydraulic cylinder 21 may be connected to a hydraulic pump via a leveling valve that detects the vehicle height and supplies or discharges pressure oil, or may be manually operated to supply hydraulic pressure. Alternatively, it may be connected to a hydraulic pump via a manually operated device such that it can be discharged.

In the first embodiment of the invention shown in FIG.
The support part 6 is a spring bracket 25, and the support part vertical mechanism 8 is a spring bracket 25.
Fastening elements that tighten the bolts and nuts 26
The spring bracket 25 is made up of an operating mechanism 28 that tightens or loosens the spring bracket 25, and a vertical operating mechanism 29 that moves the spring bracket 25 up and down with respect to the vehicle body 1. In the operating mechanism 28, a hydraulic cylinder 30 is connected to the chassis frame 2.
A link 32 is connected to the piston rod 31, and another link 27 is connected to the link.
are connected to each other, and a tightening lever 33 fixed to a nut 26a is connected to each link.
The nut 26a is adapted to tighten the spring bracket 25 via a washer 34.
The spring bracket 25 is provided with a pair of elongated holes 25a in the vertical direction, and a bolt 26b integral with the chassis frame 2 is engaged with the elongated holes. The chassis frame 2 is provided with a pair of guide portions 2a that guide the spring bracket 25 in the vertical direction.

The vertical operation mechanism 29 employs a hydraulic cylinder 17 fixed to the chassis frame 2, a spring bracket 25 is fixed to its piston rod 35, and the center portion 4a of the leaf spring 4 is pivoted to a spring pin 36. There is.

As in the first embodiment, the hydraulic cylinders 30 and 17 may be connected to a hydraulic pump via a leveling valve, or may be connected to a hydraulic pump via a manual operating device, although illustration is omitted. good. Although only the left side of the leaf spring 4 is shown in FIG. 3, the right side also has a similar configuration.

In the second embodiment shown in FIG. 4, the operating mechanism 28 and the vertical operating mechanism 29 include a hydraulic cylinder 3
0, 17 are replaced with electric motors 36, 37, respectively, and the rotating shafts 36a, 37a of the respective electric motors are
This embodiment differs from the second embodiment in that sliders 38 and 39 with square cross sections are used, which are screwed into feed screws 36b and 37b, respectively, which are integral with the sliders, and a link 32 or a spring bracket 6 is connected to the sliders. Since the other parts are the same as those in the first embodiment, the same parts are given the same reference numerals in the drawings and their explanation will be omitted.

The sliders 38 and 39 each have a hole 40 with a square cross section.
The electric motors 36 and 41 are housed in sleeves 40 and 41 having grooves a and 41a, and the sleeves are fixed to the chassis frame 2, and the electric motors 36 and 37 are fixed to the sleeves, respectively.

In the reference example shown in FIG. 5, the support part 6 is
Auxiliary spring 43 attached to the top of the main spring 42
A pair of sliding seats 44 support the upper surface 43a of the slider, and the support part up-and-down mechanism 8 includes a sliding seat up-and-down operation mechanism 45 that moves the sliding seats up and down. Vertical operation mechanism 4
5 employs a hydraulic cylinder 46, and a sliding seat 44 is fixed to a piston rod 48. Note that the spring plate 50 of the stacked leaf spring 49 consisting of the main spring 42 and the auxiliary spring 43 has an eye portion 50a pivoted to a spring pin 52 of a spring bracket 51 fixed to the chassis frame 2, and an end portion 50b of the spring plate 50 of the stacked leaf spring 49. It is supported by a shaft 53 which is pivotally connected to the chassis frame 2 so as to be swingable.

In this case as well, the hydraulic cylinder 46 may be connected to a hydraulic pump via a leveling valve or via a manual operating device.

Effects The present invention is configured as described above, and its effects will be explained below. 1 and 2, when pressure oil is supplied from the hydraulic pump to the hydraulic cylinder 21 via a leveling valve or a manual operating device, the piston rod 22 protrudes downward and the square piece 24 moves into the elongated hole 10a of the shaft 10. The spring pin 23 moves along the two arcs A and B shown in FIG. 1, and stops at the intersection P of these arcs. Note that the arc A is centered on the pin 20, and the arc B is centered on the spring pin 18. This movement of the spring pin 23 is the same as a change in the length of the shackle 10, and the axle 14 moves in an arc C with the spring pin 18 in the middle, as shown by the imaginary line in FIG. descend along. As a result, the vehicle height becomes higher.

Further, when the piston rod 22 of the hydraulic cylinder 21 is retracted, the spring pin 23 rises and the axle 14 also rises, so that the vehicle height is lowered. In this way, the vehicle height can be changed by automatically or manually changing the length of the shank 10 through the action of the variable shank length mechanism 11.

In FIG. 3, since pressure oil is supplied to the upper side of the piston (not shown) of the hydraulic cylinder 17 and the oil is locked, the piston rod 35 can support a part of the vehicle weight, and the hydraulic cylinder 30 Pressure oil is also constantly supplied to the left side of the piston (not shown), so the piston rod 31 protrudes to the right, rotates the lever 33 clockwise in the figure via links 32 and 33, and rotates the nut 26a.
The spring bracket 25 is pressed and fixed to the chassis frame 2 via the washer 34. As a result, the spring bracket 25 is integrated with the chassis frame 2, and the spring pin 3
6 is kept at a constant height and the vehicle height does not change.

When pressure oil is supplied to the right side of the piston 30 from a leveling valve (not shown) or a manual operation device (not shown), the piston rod 31 is pulled to the left and the lever 33 is rotated counterclockwise in the figure. The nut 26a is loosened. Even in this case, the spring bracket 25 does not move because the hydraulic cylinder 17 is in the oil lock state, but when pressure oil is further supplied to the upper side of the piston of the hydraulic cylinder 17, the piston rod 35 protrudes downward to overcome the weight of the vehicle, and the spring bracket 25 descends,
The spring pin 36 also lowers, and the vehicle height becomes higher.
At this time, the spring bracket 25 is attached to the guide 2a.
Since it descends while being guided by, it does not fall down on the way and descends smoothly. Further, the bolt 26b rises relative to the elongated hole 25a, and the length of the elongated hole determines the maximum value of vehicle height adjustment. The same thing is done on the right side of the leaf spring 4, the leaf spring 4 descends without tilting, the vehicle height rises, and when a predetermined value is reached, the piston rod 35 stops, the hydraulic cylinder 17 is oil-locked, and then the hydraulic The cylinder 30 operates, the piston rod 31 protrudes to the right again, and the lever 33 rotates clockwise to tighten the nut 26a, so the spring bracket 25 is fixed to the chassis frame 2, and the vehicle height is then kept constant. dripping

In addition, when lowering the vehicle height, the hydraulic cylinder 17
The piston rod 35 of the vehicle is pulled upward, the spring bracket 25 is raised, the spring pin 36 is raised, the vehicle height is lowered, and the other functions operate in the same manner as described above to maintain the desired vehicle height.

In FIG. 4, when raising the vehicle height, the electric motor 36 rotates in a direction to pull the slider 38 to the left, and the slider 38 moves to the left by rotation of the feed screw 36b. The lever 33 rotates counterclockwise in the figure, the nut 26a is loosened, the electric motor 37 rotates, the slider 39 is lowered by the feed screw 37b, and the spring bracket 2
5 overcomes the weight of the vehicle and descends, the vehicle height increases, the electric motor 37 stops, the electric motor 36 rotates in the opposite direction to the above, the slider 38 protrudes to the right, and the nut 26a tightens. The spring bracket 25 is held in place and the vehicle height is maintained at the desired height. When lowering the vehicle height, the electric motor 37 rotates in the opposite direction to the above, the spring bracket 25 rises, and the vehicle height lowers. Such vehicle height adjustment can be done automatically or manually using the electric motor 36,
37 can be activated.

In FIG. 5, when pressure oil is supplied to the hydraulic cylinder 46 and the piston rod 48 descends, the sliding seat 44 descends and the auxiliary spring 4
The timing of contact with the upper surface 43a of 3 becomes earlier, and when contact occurs, the spring constant of the entire stacked leaf spring 49 increases rapidly, so the deflection is reduced and the vehicle height is increased accordingly. Furthermore, when the hydraulic cylinder 46 acts in the opposite direction, the sliding seat 44 retreats upward, so the timing at which it contacts the upper surface 43a of the auxiliary spring 43 is delayed, the amount of deflection of the stacked leaf spring 49 increases, and the sliding seat 44 moves upward. The height decreases.

As described above, according to the present invention, the vehicle height of the vehicle can be changed automatically or manually in any of the embodiments.

Effects Since the present invention is constructed and operates as described above, the leaf spring support part of the leaf spring support mechanism for the car body is configured to be movable up and down with respect to the car body, resulting in an extremely simple structure. Therefore, it has the effect of adjusting the vehicle height of a vehicle that uses only leaf springs, and as a result, it is possible to lower the minimum ground clearance of a bus or a truck when the vehicle is empty without hindering the running of the vehicle when the vehicle is loaded. You can get the desired effect. Further, it is possible to obtain a vehicle height adjustment device having a vehicle height adjustment function similar to that of an air spring without employing an expensive air spring, which has the effect of reducing costs and weight. Furthermore, since an operating mechanism is provided that tightens or loosens the fastening element that tightens and fixes the spring bracket to the chassis frame, the operating mechanism can be used to maintain the vehicle height at a constant value without changing the vehicle height. Since the fastening element can be tightened, the spring bracket does not move up and down, which has the effect of preventing the vehicle height from changing involuntarily while the vehicle is running or stopped, and when changing the vehicle height. By loosening the fastening element using the actuating mechanism, the load on the hydraulic cylinder can be reduced and the vehicle height can be changed with a small force, which is an extremely excellent effect.

[Brief explanation of the drawing]

The drawings relate to reference examples and embodiments of the present invention.
The figure is a side view of a suspension system equipped with a vehicle height adjustment device according to a reference example, FIG. 2 is a schematic side view illustrating the operation of the device shown in FIG. 1, and FIG. 3 is a vehicle height adjustment device according to the first embodiment. FIG. 4 is a partial vertical sectional side view of a vehicle height adjustment device according to a second embodiment, and FIG. 5 is a side view of a suspension system equipped with a vehicle height adjustment device according to a reference example. 1 is a vehicle body, 2 is a chassis frame which is an example of a part of the vehicle body, 2a is a guide portion, 3 is a support mechanism, 4 is a leaf spring, 5 is a suspension device, 6 is a support portion, 8 is a support portion vertical mechanism, 10 1 is a shaft, 11 is a variable shaft length mechanism, 25 is a spring bracket, 26 is a bolt/nut which is an example of a fastening element, 28 is an actuation mechanism, 29 is a vertical actuation mechanism, 42 is a main spring, 43
43a is an auxiliary spring, 43a is an upper surface, 44 is a sliding seat, and 45 is a sliding seat vertical movement mechanism.

Claims (1)

[Claims] 1 Used in a vehicle suspension system in which a support mechanism is provided in a part of the vehicle body and a leaf spring is supported by the support mechanism, and the leaf spring support portion of the support mechanism is configured to be movable up and down with respect to the vehicle body. In a vehicle height adjustment device provided with a support part vertical mechanism, a guide part is provided in the chassis frame in the vertical direction, and a spring bracket that supports the end of a leaf spring is attached to the guide part so as to be vertically movable, and the spring A vehicle height adjustment device comprising a fastening element that tightens and fixes the bracket to the chassis frame, a vertical operating mechanism that moves the spring bracket up and down, and an operating mechanism that tightens or loosens the fastening element.