JP4483701B2 - Hydraulic suspension system for multi-axis vehicles - Google Patents

Description

  The present invention relates to a hydraulic suspension device for a multi-axle vehicle having three or more axles such as a large crane vehicle.

  Conventionally, as a hydraulic suspension device for multi-axle vehicles, hydraulic cylinders that support sprung loads are provided on both the left and right sides of each axle, and an accumulator is connected to this hydraulic cylinder to exert its anti-vibration function. There is known one that can adjust the vehicle height by controlling the hydraulic pressure supplied from the power source. In this type of hydraulic suspension device, particularly in the case of a multi-axle vehicle, the expansion side oil chambers and the contraction side oil chambers of the hydraulic cylinders of a plurality of adjacent axles are communicated with each other through a communication oil passage. Of these, it is common to configure a so-called parallel circuit in which a communication oil passage that communicates between the extension-side oil chambers communicates with one accumulator. The reason for configuring this parallel circuit is to reduce the number of accumulators and to prevent the wheels from greatly bouncing and concentrating the load when the wheels run on the road surface protrusions.

  By the way, in a multi-axle vehicle, it may be desired to appropriately distribute the axle load of each axle (the sum of loads supported by the left and right wheels) for each axle. For example, in order to meet safety standards for traveling of a bridge or the like, it is desired to increase the axle weight of the foremost axle and the rearmost axle and to reduce the axle weight of the intermediate axle. Also, if the unsprung load of each axle varies depending on the presence or absence of a drive unit, etc., to ensure running stability, the sprung load of the axle with a large unsprung load is reduced and the sprung of the axle with a small unsprung load is secured. It is desired to increase the load so that the axle weight of each axle is equal.

Conventionally, in order to meet such demands, in particular for adapting to safety standards for traveling such as bridges, as disclosed in Patent Document 1, the inner diameter and the rod diameter of the hydraulic cylinder of each axle are disclosed. Is known to have such a dimension that the axle weight (correctly sprung load) supported by the intermediate axle hydraulic cylinder is smaller than the axle weight supported by the front and rear axle hydraulic cylinders. Yes. In this patent document 1, it is not necessary to use a closed circuit that connects the hydraulic cylinder of the intermediate axle and the accumulator as a circuit independent of the hydraulic cylinder of the foremost axle or the rearmost axle. In particular, there is an advantage that it can be applied to a three-axis or four-axis vehicle having a small number of axes.
JP 2004-114901 A

  However, in the thing of the said patent document 1, since it is necessary to adjust a shaft load using the difference in the internal diameter of a hydraulic cylinder, and the dimension of a rod diameter, according to an adjustment value, several types of hydraulic cylinders from which a dimension differs are included. There is a problem that costs such as component costs and management costs increase. Further, the increase in the number of parts is disadvantageous in terms of maintenance.

  Further, when the unsprung load of each axle varies depending on the presence or absence of a drive device, etc., it is necessary to finely adjust the axle load in order to equalize the axle load. In the axle load adjustment, the seals and bearings built into the hydraulic cylinder are usually fixed in size (5 mm to 10 mm pitch). Therefore, when fine axle load adjustment is performed, not only the hydraulic cylinder but also the built in it. Also, the seals and bearings to be manufactured must be designed and manufactured independently, and there is a problem that the cost is greatly increased.

  The present invention has been made in view of the above points, and the object of the present invention is to adjust the axle load by simple means, which is excellent in terms of cost and maintenance, and is fine without causing a significant increase in cost. It is an object of the present invention to provide a hydraulic suspension device for a multi-axis vehicle that can adjust the axle load and has excellent practicality.

To solve the above problems, the invention according to claim 1 to 3, as either a hydraulic suspension system of multi-axis vehicle, supports a sprung weight on left and right sides of the axles of a vehicle having three or more axes of the axle It is premised that a hydraulic cylinder is provided, and that the expansion side oil chambers and the contraction side oil chambers of the hydraulic cylinders of a plurality of adjacent axles communicate with each other via the extension side communication oil passage and the contraction side communication oil passage, respectively. . The mounting angle of the hydraulic cylinder is provided differently for each axle.

  In this configuration, even if the thrust of the hydraulic cylinder is the same, the mounting angle differs for each axle, so the sprung load transmitted to each axle via the hydraulic cylinder also differs for each axle. The axle weight of each axle to which unsprung load is applied can be adjusted appropriately. Moreover, when changing the mounting angle of the hydraulic cylinder for each axle, it is only necessary to change the dimensions of the bracket etc. for mounting the hydraulic cylinder, so parts cost and management compared to changing the inner diameter of the hydraulic cylinder, etc. Costs such as expenses can be reduced. Further, since the number of parts is reduced, it is advantageous in terms of maintenance. Furthermore, fine axial load adjustment can be easily performed.

The invention according to claim 1 is, as one aspect, that the mounting angle of the hydraulic cylinder is determined based on the sprung load supported by the hydraulic cylinder of the front axle and the hydraulic cylinder of the rear axle. The structure is provided differently for each axle so as to be smaller. In this configuration, due to the difference in the mounting angle of the hydraulic cylinder, the sprung load transmitted to the foremost axle and the rearmost axle is increased, and the axial load is increased, and the sprung load transmitted to the intermediate axle is decreased. It can be adapted to the safety standards when traveling such as bridges.

In another aspect of the invention according to claim 2, when the unsprung load of each axle is different depending on the presence or absence of a drive device, the mounting angle of the hydraulic cylinder is supported by the hydraulic cylinder of the axle having a large unsprung load. A structure is provided in which the sprung load is different for each axle so that the sprung load is smaller than the sprung load supported by the hydraulic cylinder of the axle with a small unsprung load. In this configuration, the sprung load transmitted to the axle with a large unsprung load decreases due to the difference in the mounting angle of the hydraulic cylinder, and the sprung load transmitted to the axle with a small unsprung load increases. The shaft weight can be adjusted to be uniform.

The invention according to claim 3, as well another embodiment, the type of request sprung load tires required for each axle, vary depending on the configuration of the size or pneumatic, the mounting angle of the hydraulic cylinder, on the request spring It is configured to be provided differently for each axle so that the actual sprung load supported by the hydraulic cylinder of the axle with a large load is larger than the actual sprung load supported by the hydraulic cylinder of the axle with a small required spring load. . In this configuration, the actual spring load supported by the hydraulic cylinder of the axle having a large required spring load is increased due to the difference in the mounting angle of the hydraulic cylinder, and the actual spring supported by the hydraulic cylinder of the axle having a small required spring load. Since the upper load becomes small, the actual sprung load can be easily and reliably adjusted without changing the size of the hydraulic cylinder as in the prior art in accordance with the required sprung load required for each axle.

The inventions according to claims 4 and 5 both provide a more specific form in the case where the mounting angle of the hydraulic cylinder is provided differently for each axle. That is, the invention according to claim 4 attaches the hydraulic cylinders on the left and right sides of each axle so as to be inclined in an octagon or an inverted octagon symmetrically with respect to the vertical line when viewed in the vehicle longitudinal direction. Different configuration for each axle. According to a fifth aspect of the present invention, the hydraulic cylinder is mounted with an inclination with respect to a vertical line when viewed from the side of the vehicle, and the inclination angle is different for each axle. Here, the inclination angle includes zero.

  As described above, according to the hydraulic suspension device for a multi-axis vehicle according to the present invention, the axle load of each axle can be adjusted appropriately depending on the difference in the mounting angle of the hydraulic cylinder. This is also advantageous in terms of maintenance. In addition, fine axial weight adjustment can be easily performed, and an effect excellent in practicality can be obtained.

In particular, in the invention according to claim 1 , due to the difference in the mounting angle of the hydraulic cylinder, the sprung load transmitted to the foremost axle and the rearmost axle and hence the axle load increases, and the sprung load and the shaft transmitted to the intermediate axle are increased. Since the weight is reduced, it can be adapted to safety standards when traveling such as bridges.

In the invention according to claim 2 , the sprung load transmitted to the axle having a large unsprung load decreases due to the difference in the mounting angle of the hydraulic cylinder, and the sprung load transmitted to the axle having a small unsprung load increases. Therefore, the axle load of each axle can be adjusted to be equal.

Further, in the invention according to claim 3 , even when the required spring load required for each axle varies depending on the type, size or air pressure setting of the tire, the actual spring load is calculated depending on the mounting angle of the hydraulic cylinder. It can be easily and reliably adjusted according to the load, and can be easily implemented.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments that are the best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 shows a truck crane A as a multi-axle vehicle equipped with a hydraulic suspension device according to a first embodiment of the present invention. Reference numeral 1 denotes a truck carrier. The chamber 2 is provided, and the track carrier 1 is provided with a first axle 3a, a second axle 3b, a third axle 3c, and a fourth axle 3d in order from the front side. Reference numeral 4 denotes an upper swing body that is mounted on the track carrier 1 so as to be capable of swinging. The upper swing body 4 is provided with a telescopic boom 5 and an operation cab 6.

  As shown in FIGS. 2 and 3, each of the axles 3a to 3d includes left and right wheels 7 and 7 that are driven to rotate as drive wheels by receiving power from a drive system (not shown). An axle housing 8 is disposed between the wheels 7 and 7 and disposed in the vehicle width direction and accommodates an axle shaft (not shown). Each of the axles 3a to 3d is attached to a carrier frame 9 that is a strength member of the track carrier 1 by using a hydraulic suspension device 10 as a suspension device.

  The hydraulic suspension device 10 includes two left and right hydraulic cylinders 11 and 11 for supporting the sprung loads provided on the left and right sides of the axle housing 8 and the torque generated in the axle housing 8 for each of the axles 3a to 3d. One upper torque rod 12 and two left and right lower torque rods 13 and 13 for supporting the reaction force, and a lateral rod 14 for suppressing the roll of the track carrier 1 are provided. Each hydraulic cylinder 11 is arranged on the side of the carrier frame 9 with the rod 11f facing down, and the upper end of each hydraulic cylinder 11 on the head 11e side is connected to the carrier frame 9 via the mounting bracket 16. The lower end, which is the end on the rod 11 f side, is connected to the axle housing 8.

  4 shows a hydraulic circuit of the hydraulic suspension device 10, wherein 11a is a hydraulic cylinder on the right side of the first axle 3a, 11b is a hydraulic cylinder on the right side of the second axle 3b, 11c is a hydraulic cylinder on the right side of the third axle 3c, 11d is a hydraulic cylinder on the right side of the fourth axle 3d.

  Among the four hydraulic cylinders 11a to 11d on the right side, the extension side oil chamber 21 of the first axle hydraulic cylinder 11a and the extension side oil chamber 21 of the second axle hydraulic cylinder 11b are connected via the extension side communication oil passage 23. The extension-side oil chamber 21 of the three-axle hydraulic cylinder 11c and the extension-side oil chamber 21 of the fourth axle hydraulic cylinder 11d are communicated with each other via an extension-side communication oil passage 24. Further, the contraction side oil chamber 22 of the first axle hydraulic cylinder 11a and the contraction side oil chamber 22 of the second axle hydraulic cylinder 11b are connected via a contraction side communication oil passage 25 to the contraction side oil chamber of the third axle hydraulic cylinder 11c. 22 and the contraction-side oil chamber 22 of the fourth axle hydraulic cylinder 11d communicate with each other via a contraction-side communication oil passage 26.

  The extension side communication oil passages 23 and 24 are connected to accumulators 31 and 32 via double pilot check valves 27 and 28 and accumulator oil passages 29 and 30, respectively. A switching valve (not shown) is connected to each double pilot check valve 27, 28 via a pilot oil passage 33, 34, and a pilot is connected to each double pilot check valve 27, 28 by switching the switching valve to the open position. When the hydraulic pressure is applied, the double pilot check valves 27 and 28 are opened.

  Reference numerals 35 and 36 denote vehicle height adjusting electromagnetic switching valves connected to the accumulators 31 and 32 through supply / discharge oil passages 37 and 38 and pilot check valves 39 and 40, respectively. , 36 are in the lower position as shown in the drawing, the oil supply / discharge oil passages 37, 38 are connected to the tank port T, and the pilot check valves 39, 40 are closed. When the double pilot check valves 27 and 28 are opened in this state, the extension side oil chamber 21 of the first axle hydraulic cylinder 11a and the extension side oil chamber 21 of the second axle hydraulic cylinder 11b are transferred to the accumulator 31 and the third axle hydraulic pressure. The extension-side oil chamber 21 of the cylinder 11c and the extension-side oil chamber 21 of the fourth axle hydraulic cylinder 11d communicate with the accumulator 32 to form a closed circuit, thereby achieving a vibration-proof function.

  On the other hand, when the electromagnetic switching valves 35 and 36 are switched to position C with the double pilot check valves 27 and 28 opened, the hydraulic oil from the pump port P is supplied to the pilot check valves 39 and 40, the supply / discharge oil passage 37, 38, through the accumulator oil passages 29, 30 and the double pilot check valves 27, 28, flows into the extension side oil chambers 21 of the hydraulic cylinders 11a to 11d, and the hydraulic cylinders 11a to 11d extend to raise the vehicle height. Do. Further, when the electromagnetic switching valves 35 and 36 are switched to the A position with the double pilot check valves 27 and 28 opened, the hydraulic oil in the extension side oil chambers 21 of the hydraulic cylinders 11a to 11d is double pilot check valve. 27, 28, accumulator oil passages 29, 30, supply / discharge oil passages 37, 38 and pilot check valves 39, 40, and flow out to the tank port T to reduce the hydraulic cylinders 11a to 11d and lower the vehicle height. Do.

  In FIG. 4, reference numeral 41 denotes a first communicating passage between the contraction side communication passage 25 between the first and second axle hydraulic cylinders 11a and 11b and the expansion side communication passage 24 between the third and fourth axle hydraulic cylinders 11c and 11d. The first cross oil passage 42 communicates the expansion side communication passage 23 between the first and second axle hydraulic cylinders 11a and 11b and the contraction side communication passage 26 between the third and fourth axle hydraulic cylinders 11c and 11d. Cross passage. Further, FIG. 4 shows only the right four hydraulic cylinders 11a to 11d and their peripheral configurations in the hydraulic circuit of the hydraulic suspension device 10, but the left four hydraulic cylinders 11a to 11d and their peripheral configurations are also the same. It has become.

  In the hydraulic suspension apparatus 10 configured as described above, if all the hydraulic cylinders 11 of the axles 3a to 3d have the same dimensions and the same mounting state, the transmission is transmitted to the axles 3a to 3d via the hydraulic cylinder 11. The sprung load is the same as when the sprung load is directly transmitted to each axle 3a-3d without passing through the hydraulic cylinder 11, and the axle weight of each axle 3a-3d cannot be adjusted. In the case of this embodiment, in order to conform to safety standards at the time of traveling such as a bridge, the mounting angle of the hydraulic cylinder 11 is different for each of the axles 3a to 3d, and the second axle 3b and the third axle 3c, which are intermediate axles. The sprung load supported by the hydraulic cylinders 11 (11b, 11c) is supported by the hydraulic cylinders 11 (11a, 11d) of the first axle 3a, which is the front axle, and the fourth axle 3d, which is the rear axle. It is provided so as to be smaller than the sprung weight to.

  That is, in the first axle 4a and the fourth axle 3d, as shown in FIG. 2, the left and right hydraulic cylinders 11, 11 are symmetrical and parallel to the vertical line when viewed in the vehicle longitudinal direction (in other words, vertical). The sprung load is transmitted to the axle 3a or 3d with 100% of the thrust of each hydraulic cylinder 11. On the other hand, in the second axle 3b and the third axle 3c, as shown in FIG. 3, the two left and right hydraulic cylinders 11 and 11 are tilted at a predetermined angle .alpha. The sprung load is transmitted to the axle 3b or 3c by the cos α times the thrust of each hydraulic cylinder 11. When viewed from the side of the vehicle body, the hydraulic cylinder 11 is attached in the vertical state with the same axles 3a to 3d as shown in FIG.

  Therefore, in the first embodiment, the mounting angle of the hydraulic cylinder 11 is different for each of the axles 3a to 3d, and the sprung load supported by the hydraulic cylinders 11 of the second axle 3b and the third axle 3c is the first axle. 3a and the fourth axle 3d are smaller than the sprung load supported by the respective hydraulic cylinders 11, so that the axle load of the second and third axles 3b and 3c is reduced, and the shafts of the first and fourth axles 3a and 3d are reduced. The weight can be increased, and it can be adapted to safety standards when traveling such as bridges.

  In addition, when the mounting angle of the hydraulic cylinder 11 is changed for each of the axles 3a to 3d, it is only necessary to change the dimensions of the mounting bracket 16 and the like for mounting the hydraulic cylinder 11, so that the inner diameter of the hydraulic cylinder 11 is conventionally known. Costs such as component costs and management costs can be reduced as compared with the case of changing the above. Further, since the number of parts is reduced, it is advantageous in terms of maintenance. Furthermore, since fine adjustment of the axial load can be easily performed, it has an effect of excellent practicality.

  FIG. 5 shows a truck crane B provided with a hydraulic suspension device according to a second embodiment of the present invention. The configuration of the truck crane B is the same as that of the truck crane A of the first embodiment except for the following points including the hydraulic suspension device 10. Is omitted.

  In the case of the first embodiment, when the mounting angle of the hydraulic cylinder 11 (11a to 11d) is set differently for each of the axles 3a to 3d in order to conform to safety standards at the time of traveling such as a bridge, it is viewed from the front and rear direction of the vehicle. The mounting angle of the hydraulic cylinders 11 is different, but in the case of the second embodiment, the mounting angles of the hydraulic cylinders 11a to 11d as viewed from the side of the vehicle are different.

  That is, as shown in detail in FIG. 6, the hydraulic cylinder 11a of the first axle 3a and the hydraulic cylinder 11d of the fourth axle 3d are both mounted in a vertical state when viewed from the side of the vehicle. , 11d, the sprung load is transmitted to the axle 3a or 3d with 100% of the thrust. On the other hand, the hydraulic cylinder 11b of the second axle 3b and the hydraulic cylinder 11c of the third axle 3c are both inclined at a predetermined angle β with respect to the vertical line, with the upper side (head 11e) side rearward or forward relative to the vertical line. The sprung load is transmitted to the axle 3b or 3c with the cos β times the thrust of each of the hydraulic cylinders 11b and 11c.

  In the second embodiment, as in the case of the first embodiment, the axle load of the second and third axles 3b and 3c is reduced by the difference in the mounting angle of the hydraulic cylinder 11, and the first and first axles are reduced. Since the axle weight of the four axles 3a and 3d can be increased, it can be adapted to safety standards for traveling such as bridges, and in addition, costs such as component costs and management costs can be reduced. Of course, it has such effects as.

  FIG. 7 shows a truck crane C provided with a hydraulic suspension device according to a third embodiment of the present invention. In the case of the third embodiment, the configuration of the drive system of the truck crane C is different from that in the case of the first embodiment.

  That is, in FIG. 7, 51 is an engine mounted on the track carrier 1, 52 is a transmission connected to the engine 51, 53 is an auxiliary for distributing power transmitted from the transmission 52 via the propeller shaft 54. A transmission 55 is a differential gear provided on the second axle 3 b (specifically, the axle housing 8). The differential gear 55 transmits one power distributed by the sub-transmission 53 via the propeller shaft 56. It is for distributing and transmitting to the left and right wheels 7 of the second axle 3b via a receiving and axle shaft (not shown).

  Reference numeral 57 denotes a differential gear provided on the third axle 3c. The differential gear 57 receives the other power distributed by the auxiliary transmission 53 via the propeller shaft 58, and the right and left of the third axle 3c. This is for distributing and transmitting to the wheel 7 and the fourth axle 4c side. 59 is a differential gear provided on the fourth axle 3d, and this differential gear 59 transmits the power transmitted through the differential gear 57 on the third axle 3c side to the left and right wheels 7 of the fourth axle 3d. It is for distributing and transmitting. As described above, of the four axles 3a to 3d, the wheels 7 of the second axle 3b, the third axle 3c, and the fourth axle 3d are rotationally driven as drive wheels. In addition, the other structure of the truck crane C is substantially the same as that of the truck crane A of the first embodiment, and the same members are denoted by the same reference numerals and description thereof is omitted.

  In the case of the drive system as described above, the first axle 3a is lighter because there is no driving device such as a differential gear, and the unsprung load, which is its weight, is reduced, whereas the second to fourth axles 3b to 3d. Are heavier due to the presence of driving devices such as differential gears 55, 57 and 59, and the unsprung load increases. In the third embodiment, when the unsprung loads of the axles 3a to 3d are different from each other, the mounting angle of the hydraulic cylinder 11 is adjusted to make the axle weights of the axles 3a to 3d uniform. The sprung load supported by the hydraulic cylinder 11 of the first axle 3a having a small unsprung load is supported by the hydraulic cylinder 11 of the second to fourth axles 3b to 3d having a large unsprung load. It is provided to be smaller than the load.

  That is, in the first axle 3a, the two left and right hydraulic cylinders 11 and 11 are perpendicular to the vertical line when viewed in the vehicle longitudinal direction, as in the first axle 4a and the fourth axle 3d in the first embodiment shown in FIG. They are mounted symmetrically and parallel to each other, and the sprung load is transmitted to the axle 3a with 100% of the thrust of each hydraulic cylinder 11. On the other hand, in the second to fourth axles 3b to 3d, the two left and right hydraulic cylinders 11 and 11 are seen in the vehicle front-rear direction as in the second axle 3b and the third axle 3c in the first embodiment shown in FIG. In this case, it is attached in a C-shape symmetrically with respect to the vertical line and inclined at a predetermined angle α, and the sprung load is transmitted to the axles 3b to 3d by cos α times the thrust of each hydraulic cylinder 11. ing.

  Therefore, in the third embodiment, the mounting angle of the hydraulic cylinder 11 is different for each of the axles 3a to 3d, and the sprung load supported by the hydraulic cylinders 11 of the second to fourth axles 3b to 3d having a large unsprung load. And the sprung load supported by the hydraulic cylinder 11 of the first axle 3a having a small unsprung load is increased, so that the axle weights of the axles 3a to 3d can be adjusted to be equal.

  Moreover, as in the case of the first embodiment, when the mounting angle of the hydraulic cylinder 11 is changed for each of the axles 3a to 3d, it is sufficient to simply change the dimensions of the mounting bracket 16 and the like for mounting the hydraulic cylinder 11. Thus, it is possible to reduce costs such as parts cost and management cost, and there are advantages such as being advantageous in terms of maintenance.

  FIG. 8 shows a truck crane D provided with a hydraulic suspension device according to a fourth embodiment of the present invention. In the case of the fourth embodiment, among the four axles 3a to 3d, the size of each wheel 7a of the first axle 3a and the fourth axle 3d (and thus the tire constituting the main part) is set large, and the middle The size of each wheel 7b of the 2nd axle 3b and the 3rd axle 3c which are axles is set up small.

  Further, the required sprung load, which is the sprung load required for each of the axles 3a to 3d, differs depending on the size of the wheels 7a, 7b, and the required sprung load for the first axle 4a and the fourth axle 3d where the wheel 7a is large. The required sprung load is small in the second axle 3b and the third axle 3c having a large wheel 7b and a small size.

  In order to match the actual sprung load with such a required sprung load, the mounting angles of the hydraulic cylinders 11a to 11d are provided differently for each of the axles 3a to 3d. In particular, in the case of the present embodiment, as in the case of the second embodiment, the mounting angles of the hydraulic cylinders 11a to 11d as seen from the side of the vehicle are different for each axle 3a to 3d, and the axle has a large required spring load. In the first axle 3a and the fourth axle 3d, the hydraulic cylinders 11a and 11d are mounted in a vertical state so that the actual sprung load supported by the hydraulic cylinders 11a and 11d is increased, while the required sprung load is small. In the second axle 3b and the third axle 3c, which are axles, the hydraulic cylinders 11b and 11c are inclined upward or backward with respect to the vertical line so that the actual sprung load supported by the hydraulic cylinders 11b and 11c is reduced. Attached. In addition, the other structure of the truck crane D is the same as the case of the truck crane A of 1st Embodiment, The same code | symbol is attached | subjected to the same member and the description is abbreviate | omitted.

  Therefore, in the fourth embodiment, when the required sprung load required for each of the axles 3a to 3d varies depending on the size of the wheels 7a and 7b, the first axle 4a and the fourth axle 3d having a large required sprung load are used. The hydraulic cylinders 11a and 11d are mounted in a vertical state so that the actual sprung load supported by the hydraulic cylinders 11a and 11d is increased, and the hydraulic cylinder 11b is used for the second and third axles 3b and 3c having a small required spring load. Since the hydraulic cylinders 11b and 11c are attached to be inclined with respect to the vertical line so that the actual sprung load supported by the cylinders 11c is reduced, each of the hydraulic cylinders 11a to 11d can be changed without changing the size of the hydraulic cylinders 11a to 11d as in the prior art. The actual sprung load on the axles 3a to 3d can be easily and reliably adjusted to the required sprung load.

  The present invention is not limited to the first to fourth embodiments, but includes various other embodiments. For example, in the first embodiment, when the mounting angle of the hydraulic cylinder 11 is set differently for each of the axles 3a to 3d, the mounting angle of the hydraulic cylinder 11 as viewed from the vehicle front-rear direction is different. In the second embodiment, Although the mounting angle of the hydraulic cylinder 11 as viewed from the side of the vehicle is different, the present invention may combine both of them, and the same effect can be achieved.

  In the first embodiment, when the mounting angle of the hydraulic cylinder 11 as viewed from the front-rear direction of the vehicle is provided differently for each of the axles 3a to 3d, the two left and right hydraulic cylinders 11 and 11 are symmetrical with respect to the vertical line. However, in the present invention, the left and right hydraulic cylinders 11 and 11 of all the axles 3a to 3d are horizontally or symmetrically shaped symmetrically with respect to the vertical line. The tilt angle α may be set differently for each of the axles 3a to 3d.

  Further, in the second embodiment, when the mounting angle of the hydraulic cylinder 11 as viewed from the side of the vehicle is provided differently for each of the axles 3a to 3d, the hydraulic cylinders 11a to 11d of the axles 3a to 3d are placed in a vertical state or Although attached with inclination with respect to the vertical line, in the present invention, the hydraulic cylinders 11a to 11d are attached with inclination with respect to the vertical line on all the axles 3a to 3d, and the inclination angle β is different for each of the axles 3a to 3d. You may do it.

  In addition, in each of the above embodiments, the case where the present invention is applied to the truck cranes A to D having the four axles 3a to 3d has been described. However, the present invention is not limited to this case, and three or more axles are used. The present invention can be widely applied to a hydraulic suspension device for a multi-axis vehicle.

1 is a side view of a truck crane according to a first embodiment of the present invention. It is the arrow line view seen along the XX line of FIG. It is the arrow line view seen along the YY line of FIG. It is a hydraulic circuit diagram of a hydraulic suspension device. FIG. 3 is a view corresponding to FIG. 1 showing a second embodiment. It is a schematic diagram which shows the attachment state seen from the vehicle body side of the hydraulic cylinder of each axle of a hydraulic suspension apparatus. It is a side view seeing through and showing a part (drive system) of a truck crane concerning a 3rd embodiment. FIG. 10 is a view corresponding to FIG. 1 and showing a fourth embodiment.

Explanation of symbols

A, B, C, D Truck crane 3a, 3b, 3c, 3d Axle 7, 7a, 7b Wheel (tire)
DESCRIPTION OF SYMBOLS 10 Hydraulic suspension apparatus 11 Hydraulic cylinder 11a Hydraulic cylinder of 1st axle 11b Hydraulic cylinder of 2nd axle 11c Hydraulic cylinder of 3rd axle 11d Hydraulic cylinder of 4th axle 21 Expansion side oil chamber 22 Contraction side oil chamber 23, 24 Extension side Connection oil passage 25, 26 Contraction side communication oil passage 55, 57, 59 Differential gear (drive device)
α, β Hydraulic cylinder tilt angle

Claims (5)

Hydraulic cylinders that support sprung loads are provided on the left and right sides of each axle of a vehicle having three or more axles, and the expansion side oil chambers and the contraction side oil chambers of the hydraulic cylinders of a plurality of adjacent axles are In a hydraulic suspension device for a multi-axis vehicle that is in communication with each other via an extension side communication oil passage and a contraction side communication oil passage,
The mounting angle of the hydraulic cylinder is different for each axle so that the sprung load supported by the hydraulic cylinder of the intermediate axle is smaller than the sprung load supported by the hydraulic cylinder of the front axle and the rear axle. A hydraulic suspension device for a multi-axis vehicle. Hydraulic cylinders that support sprung loads are provided on the left and right sides of each axle of a vehicle having three or more axles, and the expansion side oil chambers and the contraction side oil chambers of the hydraulic cylinders of a plurality of adjacent axles are In a hydraulic suspension device for a multi-axis vehicle that is in communication with each other via an extension side communication oil passage and a contraction side communication oil passage,
When the unsprung load of each axle differs depending on the presence or absence of a drive device, the mounting angle of the hydraulic cylinder is such that the axle spring cylinder with a large unsprung load supports the unsprung load with a small unsprung load. A hydraulic suspension device for a multi- axle vehicle, wherein the suspension is provided differently for each axle so as to be smaller than the sprung load supported by the vehicle. Hydraulic cylinders that support sprung loads are provided on the left and right sides of each axle of a vehicle having three or more axles, and the expansion side oil chambers and the contraction side oil chambers of the hydraulic cylinders of a plurality of adjacent axles are In a hydraulic suspension device for a multi-axis vehicle that is in communication with each other via an extension side communication oil passage and a contraction side communication oil passage,
If the required sprung load required for each axle differs depending on the type, size or air pressure setting of the tire, the mounting angle of the hydraulic cylinder is the actual sprung mass supported by the hydraulic cylinder of the axle with the large required sprung load. A hydraulic suspension device for a multi- axle vehicle, wherein the load is provided differently for each axle so that the load is larger than an actual sprung load supported by a hydraulic cylinder of an axle having a small required spring load . The hydraulic cylinders on both the left and right sides of the axles are mounted so as to be inclined in an octagon or an inverted octagon symmetrically with respect to the vertical line when viewed in the vehicle longitudinal direction, and the inclination angle differs for each axle. The hydraulic suspension device for a multi-axis vehicle according to any one of claims 1 to 3 . The multi-axis according to any one of claims 1 to 4, wherein the hydraulic cylinder is mounted to be inclined with respect to a vertical line when viewed from the side of the vehicle, and the inclination angle is different for each axle. Hydraulic suspension device for vehicles.

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