WO1999050080A1

WO1999050080A1 - Air suspension device for vehicle

Info

Publication number: WO1999050080A1
Application number: PCT/JP1999/001582
Authority: WO
Inventors: Yuujin Nanbu
Original assignee: Hino Jidosha Kabusiki Kaisha
Priority date: 1998-03-31
Filing date: 1999-03-29
Publication date: 1999-10-07
Also published as: JPH11278030A

Abstract

An air suspension device for vehicle, comprising a first air spring (13) and a second air spring (14) disposed on a chassis frame (12) at the front and rear of an axle (11), an axle housing (17) for holding the axle (11) rotatably on a frame member (16) having a front end connected to the first air spring (13) and a rear end connected to the second air spring (14), an upper rod (21) and a lower rod (22) on end thereof being pivotally supported on the upper and lower parts of the axle housing (17), respectively, and the other end thereof (21, 22) being pivotally supported on the chassis frame (12) at the front and rear of the axle housing (17), respectively, wherein a distance dimension value (A) between the second air spring (14) and the axle (11) is made larger than that (B) between the first air spring (13) and the axle (11), whereby a required strength is decreased so as to reduce the weight of the upper and lower rods and its durability can be increased.

Description

Description Vehicle alarm device Technical field

The present invention relates to an air suspension device for a vehicle using four air springs per shaft. Background art

2. Description of the Related Art Conventionally, there has been known an air suspension pen device in which front and rear ends of left and right erection members whose substantially centers are fixed to left and right lower surfaces of an axle housing are connected to a chassis frame by air springs. As shown in FIG. 3, a first air spring 3 and a second air spring 4 are provided on a chassis frame 2 on the left and right sides of an axle 1 in this device. The front end of the left erection member 6 is attached to the first air spring 3 and the rear end thereof is adhered to the second air spring 4, together with the first and second air springs attached to the right erection member (not shown). Four air springs are used. An axle housing 7 for rotatably holding the axle 1 is mounted substantially at the center of the erection member 6, and the axle 1 is rotated by an output of an engine (not shown) to rotate wheels provided at both ends thereof, thereby allowing the vehicle to rotate. You can now run. By supporting the vehicle body with the air springs 3 and 4, the resonance point on the panel can be set lower and fine vibrations can be absorbed compared to the method in which the vehicle body is supported by metal springs. The ride comfort can be improved.

On the other hand, in such an air suspension device, one end of the upper rod 8 and one end of the lower rod 9 are pivotally supported on the upper and lower parts of the axle housing 7, and the other end of the upper rod 8 and the other end of the lower rod 9 are located forward or forward of the axle housing 7. Each is pivoted to the rear chassis frame 2. The upper rod 8 and the lower rod 9 correspond to the chassis frame 2 of the axle housing 7. To prevent excessive rotation of the axle housing 7 due to the driving torque or the braking torque of the wheels 1a, and to prevent the axle 1 from being tramped. For this reason, the strength of the upper rod 8 and the lower rod 9 is determined by the relationship with the driving torque or braking torque of the wheel 1a, and the upper rod 8 and the lower rod 9 have sufficient safety against the largest possible torque. Designed to.

Here, it is known that the largest torque that can occur is the braking torque during sudden braking while the vehicle is traveling forward, and the braking torque reduces the support load of the first air spring 3 and the second air. The supporting load of the spring 4 increases. That is, the torque expressed by the product of the load applied to the second air spring 4 and the distance between the axle 1, which is the center of rotation, and the second air spring 4, the load applied to the upper rod 8 and the lower rod 9, and the axle 1 The torque expressed by the product of the distance from the upper rod 8 and the lower rod 9 to the upper rod 8 opposes the braking torque generated in the axle housing 7 during sudden braking. Therefore, the upper rod 8 and the lower rod 9 in the conventional air suspension device are designed with sufficient strength to withstand the compressive force or the tensile force applied during sudden braking.

However, if the upper rod 8 and the lower rod 9 are manufactured based on the braking torque at the time of sudden braking, the upper rod 8 and the lower rod 9 are made with a strength higher than that required during normal running, and the weight of the upper rod 8 and the lower rod 9 becomes unnecessarily heavy. There is a problem. That is, the torque expressed by the product of the load applied to the first air spring 3 and the distance between the axle 1 force, which is the center of rotation, and the first air spring 3, and the load applied to the upper rod 8 and the lower rod 9 The torque expressed by the product of the distance from axle 1 and the axle 1 opposes the driving torque during acceleration or constant speed operation of the vehicle. Therefore, in the conventional air suspension device in which the axle housing 7 for rotatably holding the axle 1 is mounted at substantially the center of the erection member 6, the drive torque and the braking torque that the upper rod 8 and the lower rod 9 can compete with are equal, The driving torque during acceleration or constant speed operation is smaller than the braking torque during sudden braking. Therefore, the upper rod 8 and the lower rod 9 designed on the basis of the braking torque have a problem that the strength is more than necessary when the driving torque is based. SUMMARY OF THE INVENTION An object of the present invention is to provide an air suspension device for a vehicle capable of reducing the required strength and reducing the weight of an upper rod and a lower rod and improving the durability thereof. Disclosure of the invention

According to the invention of claim 1, as shown in FIG. 1, a first air spring 13 and a second air spring 14 are disposed on a chassis frame 12 around the axle 11 and the front end is a first air spring. An axle housing 17 for rotatably holding the axle 11 is attached to a bridging member 16 which is bonded to the spring 13 and a rear end of which is bonded to the second air spring 14, and is provided at upper and lower parts of the axle housing 17. One end of the parrod 21 and one end of the lower rod 22 are pivotally supported, respectively, and the other end of the upper rod 21 and the other end of the lower rod 22 are pivotally supported by a chassis frame 12 forward or rearward of the axle housing 17. This is an improvement of the air suspension device.

The characteristic configuration is that the distance dimension value A from the second air spring 14 to the axle 11 is larger than the distance dimension value B from the first air spring 13 to the axle 11.

In the invention according to claim 1, it is represented by the product of the load applied to the second air spring 14 and the distance A between the axle 11 which is the center of rotation of the axle housing 17 and the second air spring 14. Is larger than the torque expressed by the product of the load applied to the first air spring 13 and the distance B between the axle 11 and the first air spring 13. Therefore, it is expressed as the product of the load applied to the upper rod 21 and the lower rod 22 and the distance between the axle 11 and the upper rod 21 and the lower rod 22 to counteract the braking torque during sudden braking. Torque is lower than before. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a side view showing an air suspension device according to an embodiment of the present invention. FIG. 2 is a side view of a tractor that is a vehicle using the device.

FIG. 3 is a side view corresponding to FIG. 1 showing a conventional example. BEST MODE FOR CARRYING OUT THE INVENTION

Next, an embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 2, a tractor, which is a vehicle 10, is provided with a front axle 10a and a rear axle 11 via an air suspension device, and a front axle 10a is provided with a front wheel 1Ob. A rear wheel 11a is attached to the rear axle 11 respectively. A first air spring 13 and a second air spring 14 are disposed on the chassis frame 12 before and after the rear axle 11, and the front end of the mounting member 16 is adhered to the first air spring 13 and The rear end of the erection member 16 is bonded to the second air spring 14. An axle housing 17 for rotatably holding the axle is attached to the erection member 16. The axle housing 17 holds the rear axle 11 in a rotatable manner, and the axle 11 rotates by the output of an engine (not shown) to rotate the rear wheel 11 a provided at the end, thereby rotating the tractor 1. 0 is allowed to run.

As shown in FIG. 1, the first and second air springs 13 and 14 are respectively formed in an upper plate 13a and 14a, a lower plate 13b and 14b, and a cylindrical shape therebetween. Rubber film 13c, 14c. These first and second air springs 13 and 14 are attached to the lower surface of the chassis frame 12 by bonding their upper plates 13a and 14a, respectively. The front end of the bridging member 16 is bonded to the lower plate 13 b of the first air spring 13, and the rear end of the bridging member 16 is bonded to the lower plate 1 bb of the second air spring 14. To attach the axle housing 17 to the erection member 16, attach the mounting ports 19, 19 to the erection member 16 so that the mounting plate 18 and the erection member 16 sandwich the end of the axle housing 17. This is performed by screwing through the mounting plate 18. Compressed air is supplied to the inside of the rubber films 13 (:, 14c) of the first and second air springs 13 and 14, respectively. When the vehicle 10 is traveling, the first and second air springs 13 and 14 generate sudden vibrations generated by unevenness of the road surface, and the compressed air stored in the rubber films 13 c and 14 c. It is configured so that it is not absorbed by the chassis frame 12 and absorbed by the elastic force of the vehicle. Reference numeral 24 denotes a shock absorber for damping sudden vibration.

On the other hand, one end of an upper rod 21 and one end of a lower rod 22 are pivotally supported on the upper and lower portions of the axle housing 17, respectively. One end of the upper rod 21 is pivotally supported on the upper part of the large diameter portion 17a at the center of the axle housing 17, and one end is pivotally supported on the lower part of the bridging member 16 corresponding to the axle housing 17. As a result, one end of the lower rod 22 is indirectly pivotally supported by the lower portion of the axle housing 17. In the present embodiment, the other end of the upper rod 21 and the other end of the lower rod 22 are pivotally supported by a chassis frame 12 located forward of the axle housing 17. The other end of the lower rod 2 2 is pivotally supported by the lower end of the mounting member 23 whose upper end is mounted on the chassis frame 12, and the other end of the upper rod 21 is inside the chassis frame 12 corresponding to the upper end of the mounting member 23. Pivoted on.

The upper rod 21 pulls the upper part of the axle housing 17 toward the front of the vehicle, and the lower rod 22 pushes the lower part of the axle housing 17 toward the rear of the vehicle. It is configured to prohibit rotation as indicated by the dashed arrow in the diagram of FIG. On the other hand, the upper rod 21 pushes the upper part of the axle housing 17 rearward of the vehicle, and the lower rod 22 pulls the lower part of the axle housing 17 forward of the vehicle. It is configured to prohibit rotation as shown by the solid arrow in the figure. A characteristic configuration of the present invention is that the distance A between the second air spring 14 and the axle 11 is formed larger than the distance B between the first air spring 13 and the axle 11.

In the air suspension device configured as described above, when the allowable load that can be supported by the first and second air springs 13 and 14 is equal, the second air spring The torque expressed by the product of the allowable load of the axle housing 17 and the distance A between the axle 11, which is the center of rotation of the axle housing 17, and the second air spring 14 is the torque of the first air spring 13. The torque is larger than the torque expressed by the product of the allowable load and the distance B between the axle 11 and the first air spring 13. The torque expressed by the product of the allowable load of the second air spring 14 and the clearance dimension A, and the load applied to the upper rod 21 and the lower rod 22 and the clearance from the axle 11 to one end of them. The torque represented by the product opposes the braking torque generated in the axle housing 17 during sudden braking. For this reason, by forming the interval dimension A larger than the interval dimension B and increasing the torque expressed by the product of the allowable load of the second air spring 14 and the interval dimension value A, the upper rod 21 and the lower rod 2 are increased. The load applied to 2 is smaller than before. Therefore, the load applied at the time of sudden braking, which is a reference when determining the strength of the upper rod 21 and the lower rod 22, is reduced, and the required strength of the upper rod 21 and the lower rod 22 can be made smaller than before.

On the other hand, the torque expressed by the product of the load applied to the first air spring 13 and the distance B between the axle 11, which is the center of rotation of the axle housing 17, and the first air spring 13, and the upper rod 2 1 The torque expressed by the product of the load applied to the lower rod 22 and the distance between the axle 11 and one end thereof opposes the drive torque generated in the axle housing 17 during acceleration or constant speed operation. . The torque expressed by the product of the allowable load of the first air spring 13 and the clearance dimension value B is smaller than the torque expressed by the product of the allowable load of the second air spring 14 and the clearance dimension value A. . For this reason, the load applied to the upper rod 21 and the lower rod 22 when the driving torque is applied increases compared to the load applied when the same value of the braking torque is applied. The driving torque is not a problem because it is smaller than the braking torque generated during sudden braking.

In the above-described embodiment, the other end of the upper rod 21 and the other end of the lower rod 22 are pivotally supported on the chassis frame 12 in front of the axle housing 17, respectively. Axle at the other end The air suspension device may be pivotally supported on the chassis frame behind the housing. In this case, the load applied to the upper rod and the lower rod is in the opposite direction to the above-described embodiment.

As described above, according to the present invention, the distance between the second air spring at the rear of the axle and the axle is greater than the distance between the first air spring at the front of the axle and the axle. The torque expressed by the product of the load applied to the axle and the distance between the axle and the second air spring is expressed by the product of the load applied to the first air spring and the distance between the axle and the first air spring. Thus, the load applied to the upper rod and the lower rod during sudden braking can be reduced as compared with the conventional case. As a result, it is possible to reduce the weight of the upper rod and the lower rod by designing the strength required by the upper rod and the lower rod to be small, and to improve the durability of the upper rod and the lower rod by reducing the applied load as compared with the conventional case. Can be. Industrial applicability

ADVANTAGE OF THE INVENTION The air suspension device for vehicles of this invention can reduce the weight of the upper rod and lower port of the air suspension device for vehicles using four air springs per axis, and can also improve the durability.

Claims

The scope of the claims

1. A first air spring (13) and a second air spring (14) are disposed on a chassis frame (12) in front and behind an axle (11), and a front end is bonded to the first air spring (13) and a rear end is formed. An axle housing (17) for rotatably holding the axle (11) is attached to a bridging member (16) bonded to the second air spring (14), and upper rods are provided at upper and lower portions of the axle housing (17). (21) and one end of a lower rod (22) are pivotally supported, respectively, and the other end of the upper rod (21) and the other end of the lower rod (22) are forward or rearward of the axle housing (17). In the air suspension devices each pivoted to the frame (12),

The distance dimension (A) from the second air spring (14) to the axle (11) is larger than the distance dimension (B) from the first air spring (13) to the axle (11). A vehicle air suspension device characterized by the above-mentioned.