JPH11301974A - Self-propelled crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To construct a power transmission system from an engine to a differential gear by a small number of part items and at low costs, and to provide a compact and strong layout. SOLUTION: A self-propelled crane is constructed in such a manner that power from an engine 30 is transmitted through a transmission 34 to a differential gear 36. The differential gear 36 and a wheel 18R are connected to each other so as to be moved up and down relative to each other, and then the output shaft of the transmission 34 is directly connected to the input shaft of the differential gear 36. More preferably, the engine 30 or a torque converter 32 is disposed in a position directly above the differential gear 36 by directly connecting the input shaft of the transmission 34 to the output shaft thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-propelled crane provided with running wheels.

[0002]

2. Description of the Related Art An example of a conventional self-propelled crane is shown in FIGS.
As shown in FIG.

This self-propelled crane has a lower traveling body 100 capable of traveling on a road and an upper revolving body 102 having a boom or the like.
And The lower traveling structure 100 includes a body frame 104 extending in the front-rear direction, and the upper revolving structure 102 is installed on a central portion of the body frame 104 in the front-rear direction so as to be able to turn.

The rear part of the body frame 104 is shown in FIG.
(A) As shown in FIG.
5 and between these branch portions 105, the engine 110
And a torque converter 112 connected to the output shaft thereof. A cooler 111 is provided behind the engine 110. The cooler 111 cools engine cooling water, hydraulic oil for the torque converter 112, hydraulic oil and lubricating oil for the transmission 114 described later, and hydraulic oil for driving a boom, an outrigger jack, and the like.

The output shaft of the torque converter 112 faces forward, and the universal joint and the drive shaft 113
Is connected to an input shaft of a transmission (transmission and distribution machine) 114 on the front side. The transmission 114 is fixed in a downward recess 104a formed at the center of the body frame 104, and its output shaft projects forward and backward from the transmission case. A front protruding portion of the output shaft is connected to the front axle 106 via a universal joint and a drive shaft 116 extending in the vehicle longitudinal direction, while a rear projecting portion is connected to the universal joint and the drive shaft 11 extending in the vehicle longitudinal direction.
8 to the rear axle 108.

Each of the axles 106 and 108 is formed by connecting a cylindrical housing 123 extending in the left-right direction and a pair of left and right wheel supporting portions 124 for rotatably supporting a rotating shaft of the wheels 122, and is integrated. Yes, housing 123
Inside, a central differential connected to the drive shaft 116 (118) and a transmission shaft connecting the left and right output shafts of the differential and the rotating shaft of the wheels 122 are inserted. A body frame 104 is disposed on the axles 106 and 108, and the body frame 104 and the axles 106 and 108 are connected via a buffer cylinder 120 that can expand and contract in a substantially vertical direction. The axles 106 and 108 are suspended so that they can move up and down relatively.

[0007]

In the self-propelled crane shown in FIGS. 10 to 12, the rear differential gear and the rear wheel 18R are integrated as an axle 108. The differential gear and the transmission 114 must be connected via a drive shaft 118 so as to be relatively movable in the vertical direction so that the differential gear can move up and down together with the wheels. From this relationship, there are the following disadvantages.

[0008] Three drive shafts 113, 116, and 118 must be used to transmit the output of the engine 110 to each of the differential gears 106 and 108, which is uneconomical.

Due to the drive shaft 113 interposed between the engine 110 and the transmission 114, the transmission 114 is disposed at a position considerably ahead of the engine 110, that is, at a position near the center of the vehicle body. In addition, the upper swing body 102 is mounted on this portion, and the largest bending moment acts on the crane work due to structural strength.
For this reason, in this part, the shape of the body frame 104 must be complicated and large in order to secure rigidity and strength, such as increasing the cross-sectional shape of the body frame 104 in the vertical direction as shown in FIG. . Further, the place where the transmission 114 is arranged is a place where piping and wiring are most complicated, and the layout is not easy.

The drive shafts 113, 11
8, the transmission 114 can be moved closer to the rear axle 108 (that is, the rear side).
The shorter the drive shaft 118, the larger the deflection angle of the drive shaft 118 when the rear axle 108 moves up and down, and the greater the load on the universal joints at both ends. Therefore, there is a limit to the shortening of the drive shaft 118. .

For the above reasons, the transmission 114
Is located in front of the transmission 1
The distance between 14 and engine 110 also increases. Accordingly, the hydraulic piping connecting the torque converter 112 and the transmission 114 and the hydraulic piping connecting the transmission 114 and the cooler 111 which is an oil cooler become longer,
There are inconveniences that are complicated.

An object of the present invention is to provide a self-propelled crane that can solve these problems.

[0013]

According to the present invention, there is provided a self-propelled crane in which the power of an engine is transmitted to a differential via a transmission. The wheels are connected so as to be vertically displaceable relative to each other, and the input shaft of the differential device is directly connected to the output shaft of the transmission.

According to this structure, since the output shaft of the transmission is directly connected to the input shaft of the differential device, a required drive shaft is required as compared with a conventional case where a drive shaft is interposed between both shafts. Decrease in number. Also, since the distance between the transmission and the differential is reduced, the position of the transmission is accordingly
From the center in the front-rear direction of the vehicle body, which is strict in structural strength and the layout of piping and wiring is difficult, the vehicle will be displaced to the differential device side (for example, the rear side when connected to the rear differential device). In addition, since the differential device and the wheels are relatively vertically movably connected, the input shaft of the differential device and the output shaft of the transmission are directly connected (that is, the differential device and the transmission are relatively moved). There is no problem even if the connection is made impossible.

Here, "directly connecting the output shaft of the transmission and the input shaft of the differential device" means that both shafts are directly connected by a coupling or the like, or both shafts are constituted by a single shaft. Things are also included. In the latter case, the number of parts can be further reduced,
The distance between the transmission and the differential can be further reduced.

Further, an output shaft of the engine or an output shaft of a torque converter connected to the output shaft is directly connected to an input shaft of the transmission, and the engine or the torque converter is disposed directly above the differential device. Then, the power transmission system can be made more compact, and the number of drive shafts required can be further reduced. Further, since the distance between the engine and the transmission is reduced, it is possible to shorten the piping connecting the transmission to the engine or the torque converter and the piping connecting the transmission to the oil cooler behind the engine. .

Also in this case, if the output shaft of the engine or the output shaft of the torque converter connected to the output shaft and the input shaft of the transmission are constituted by a single shaft, the number of parts can be further reduced, The distance between the transmission and the engine or the torque converter can be further reduced.

In some cases, a hydraulic pump driven by engine power is connected to the engine, the torque converter, or the transmission. In this case, the hydraulic pump must be arranged at a position parallel to the transmission. Thereby, the entire structure can be made more compact.

Further, when the transmission is directly connected to an engine or a torque converter, the crane body frame is formed with a branch portion that branches left and right, and the engine, the transmission, and the differential gear are interposed between the branch portions. By arranging the device, the entire power transmission system can be arranged without inconvenience while keeping the height of the body frame low.

In this case, the differential device is fixed to the vehicle body frame side, and one end of a transmission shaft extending in the left-right direction is connected to the left and right output shafts of the differential device so that the relative angle can be changed. If the wheels are connected to the other end so that the relative angle can be changed, and these transmission shafts are arranged so that the transmission shafts penetrate each branch portion in the left-right direction, they are integrated in the left-right direction as in the related art. Body frame can be placed lower relative to the differential, compared to one that places the body frame on a lifted axle, thereby lowering the center of gravity of the entire crane and reducing its height be able to. Further, only the wheels and the wheel supporting portions are suspended from the vehicle body frame, and the suspension weight is smaller than that of a conventional system in which the entire axle is suspended on the vehicle body frame. Moreover, since the transmission shaft only penetrates the vehicle body frame instead of penetrating the entire axle including the cylindrical housing through the vehicle body frame, manufacturing is simple, and the through holes provided in the vehicle body frame can be small, There is no significant decrease in rigidity.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described with reference to the drawings.

The wheel crane (self-propelled crane) shown in FIGS. 1 to 3 includes a lower traveling body 10 that can travel on a road. The lower traveling structure 10 includes a body frame 12 extending in the front-rear direction, and an upper revolving structure 20 is supported at an intermediate portion in the front-rear direction of the body frame 12 via a ring-shaped bearing 11 so as to be rotatable around a vertical axis. A driver's cab 25 and a swing frame 21 are installed on the upper swing body 20, and a boom 23 is supported on the swing frame 21 via a horizontal boom foot pin 22 so that the boom 23 can be raised and lowered. It is driven in the undulating direction by the expansion and contraction of the.

The front portion 14 of the body frame 12 has a relatively long box-shaped cross section in a relatively small height direction.
As shown in FIG. 3 and FIG. 3, the rear portion is a bifurcated bifurcated branching portion 16 having a vertically long box-shaped cross-section. Further, a front wheel 18F and a rear wheel 18R are provided on the left and right sides of the body frame 12.

As a power transmission system, an engine 30, a torque converter 32, and a transmission (transmission and distribution machine) as shown in FIG.
34 and a rear differential gear (rear differential device) 36 are provided, and a front differential gear 38 is provided at the front portion 14 of the vehicle body frame 12. Then, the rotation output of the engine 30 is input to the transmission 34 via the torque converter 32,
The transmission 34 distributes the gears to front and rear differential gears 36 and 38.

As shown in FIG. 2, the engine 30, the torque converter 32, the transmission 34, and the rear differential gear 36 are all disposed between the two branch portions 16. The engine 30 is fixed to the body frame 12 via a bracket (not shown) with its output shaft facing forward. The torque converter 32 is directly connected to the engine output shaft, and a rear differential gear 36 is located directly below the torque converter 32. The rear differential gear 36 is connected and fixed to the lower part of both branch portions 16 via left and right brackets 37. I have.

As shown in FIGS. 1 to 5, a plurality of hydraulic pumps 40, which are rotationally driven using engine power, are connected to the torque converter 32.
With 0, hydraulic oil for driving the boom and the outrigger jack is sent under pressure. The two hydraulic pumps 40 are fixed to the front side of the torque converter 32 so as to protrude from the front side, and are provided at the upper end of the transmission 34 in a compact arrangement.

As a characteristic of this crane, the output shaft of the torque converter 32 and the input shaft of the transmission 34 are constituted by a single shaft 33.
2 is transmitted to the transmission 34 via the shaft 33 as it is. Further, the rear output shaft of the transmission 34 and the input shaft of the rear differential gear 36 are also constituted by a single shaft 35,
The rotational output of the transmission 34 is transmitted to the differential gear 36 via the shaft 35 as it is. On the other hand, a front output shaft 46 of the transmission 34 is connected via a universal joint 48 to a rear end of a drive shaft 47 running in the front-rear direction below the center of the body frame 12 so as to be variable in relative angle. The front end of 47 is connected to the input shaft of the front differential gear 38 via a universal joint 49 so that the relative angle can be changed. The front differential gear 38 is fixed in a recess formed on the lower surface of the frame front portion 14.

As described above, the output shaft of the torque converter 32 and the input shaft of the transmission 34 may be constituted by a single shaft 33, or the output shaft of the transmission 34 and the input shaft of the rear differential gear 36 may be formed simply. Instead of using a single shaft 35, the output shaft of the torque converter 32 and the input shaft of the transmission 34 are directly connected by coupling or the like, or the transmission 34
Similarly, the output shaft and the input shaft of the rear differential gear 36 may be directly connected to each other, so that the number of parts can be reduced and the layout can be made compact.

However, if the shaft is unified as described above, the number of parts can be further reduced, and the distance between the torque converter and the transmission and the distance between the transmission and the rear differential gear can be further reduced. The housing of the torque converter and the housing of the transmission can be integrated,
It is also possible to integrate the housing of the transmission and the housing of the rear differential gear.

Drive shafts (transmission shafts) 5 are connected to the left and right output shafts of the front and rear differential gears 36 and 38 via universal joints 51 (only FIGS. 3 and 5 are shown).
The inside ends of the zeros are connected to be variable in relative angle. On the other hand, the rotation shafts of the front wheel 18F and the rear wheel 18R are rotatably supported by the wheel support 19, and the outer end of the drive shaft 50 is connected to these rotation shafts via a universal joint 52 so that the relative angle can be varied. It is connected so that it becomes.

Here, the rear differential gear 36
The drive shaft 50 connected to the output shaft of FIG.
As shown in (a), the drive shaft 50 that penetrates through holes 16 a provided in the inner and outer walls of the branch portion 16 in the left-right direction and is connected to the output shaft of the front differential gear 36, Passing below.

Each wheel supporting portion 19 is connected to a branch portion 16 and a front portion 14 of the vehicle body frame 12 via a buffer cylinder 70 so as to be relatively vertically movable. As shown in FIG. 2, each buffer cylinder 70 has a large-diameter cylinder main body 71 and a telescopic rod 72 extending upward from a piston inserted into the cylinder main body 71. The upper end of the telescoping rod 72 is rotatably connected to the distal end of a bracket 58 fixed to the upper surface of the branch portion 16 via a pin 59 in the front-rear direction of the vehicle body. The buffer cylinder 70 as a whole has a posture in which its upper end is slightly inclined inward, and the center axis of the cylinder substantially coincides with the steering rotation center of the wheels 18F, 18R.

As described above, in the structure according to this embodiment, the output shaft of the torque converter 32 and the input shaft of the transmission 34 are constituted by the single shaft 33, and the output shaft of the transmission 34 and the rear differential gear 36 Since the input shaft and the single shaft 35 are configured, a single shaft 35 is used, and compared with the conventional structure in which the drive shafts are used to connect the respective shafts as in the conventional structure illustrated in FIGS.
The number of parts can be reduced, and compact arrangement is possible. Further, as a result of reducing the distance between the rear differential gear 36 and the transmission 34, the position of the transmission 34 can be shifted rearward from the conventional center position in the vehicle longitudinal direction, and the strength load on the body frame 12 at the center position is reduced. In addition to being able to reduce the power, it is possible to arrange the transmission 34 together with the engine 30 and the rear differential gear 36 between the branch portions 16, and the layout of the power transmission system becomes ideal.

Further, in this embodiment, only the differential gears 36, 38 of the axle are fixed to the body frame 12 side, and the differential gears 36, 3
8 and the wheels 18F and 18R are connected by the drive shaft 50 so as to be relatively displaceable, so that the vehicle body is further mounted on an axle integrated as a whole by using a large-diameter cylindrical housing as in the related art. The height dimension and the boom height dimension of the body frame 12 can be effectively reduced as compared with those supporting the frame. In particular, as shown in FIG. 2A, a transmission 34 and a rear differential gear 36 are arranged together with the engine 30 between the branch portions 16 so that a drive shaft 50 connected to the differential gear 36 penetrates the branch portion 16. Then, the height position of the body frame 12 can be further lowered.

In this structure, as shown in FIG. 7, two brackets 58 on the vehicle body frame 12 are arranged at predetermined intervals in the front-rear direction, and pins 59 are fixed so as to pass through these brackets 58. On the other hand, a through hole 72a having a diameter larger than that of the pin 59 is provided at the upper end of the telescopic rod 72, and a spherical bearing 90 is interposed between the inner peripheral surface of the through hole 72a and the outer peripheral surface of the pin 59. ing. The spherical bearing 90 has an outer portion 91 fixed to the inner peripheral surface of the through hole 72a.
And an inner portion 92 fixed on the outer peripheral surface of the pin 59, and these are in contact with each other by a spherical surface. Therefore, the relative angle between the bracket 58 and the telescopic rod 72 is variable in any direction.

On the other hand, the lower surface of the wheel support 19 and the branch 16
Is connected via a swing arm 80 to the lower surface of the. The swing arm 80 includes a ring-shaped base 81 and the base 81.
And an arm body 82 extending bifurcated from front to back.
The base 81 is connected to the lower surface of the wheel support 19 so that the relative angle can be changed by a spherical bearing 83 similar to the spherical bearing 90, while the end of each arm body 82 is connected to the pin 8.
4 and a spherical bearing similar to the spherical bearing 90 (not shown)
Is connected to the lower surface of the branching portion 16a via a through hole so that the relative angle can be changed. The buffer cylinder 70 is disposed so that the straight line connecting the spherical bearing 83 and the spherical bearing 90, the central axis of the buffer cylinder 70, and the steering rotation central axis substantially match.

According to this structure, since the swing arm 80 restricts the horizontal displacement of the wheel 18R (also the wheel 18F) with respect to the vehicle body frame 12, it acts on the buffer cylinder 70 accordingly. Bending load is reduced,
The strength load on the buffer cylinder 70 is reduced.

However, in the present invention, regardless of the specific suspension structure, for example, as shown in FIG. 8, the branch portion 16 is disposed above both drive shafts 50, and the cylinder body of the cushioning cylinder 60 is provided in the branch portion 16. Fix 61,
Telescopic rod 62 extending downward from cylinder body 61
May be connected to the wheel support 19.

However, in this structure, the body frame 12
And the wheel supporting portion 19 are connected only by the buffer cylinder 70, so that the strength load on the buffer cylinder 70 is relatively large. However, the structure shown in FIGS. Thereby, the strength load on the buffer cylinder 70 can be reduced.

Here, the reason why the directions of the buffer cylinders 70 and 60 are changed between the structure shown in FIG. 6 and the structure shown in FIG. 8 is in consideration of the difference in bending moment distribution in the structure. It is. That is, in the structure shown in FIG. 8, the wheel support portion 19 is supported only by the buffer cylinder 60, and the buffer cylinder 60 is in a cantilevered state as shown in FIG. The bending moment M of the cylinder 60 increases as it approaches the fixed end (upper end). Therefore, the cylinder main body 61 having higher bending rigidity than the telescopic rod 62 is disposed above. On the other hand, in the structure shown in FIG. 6, as shown in FIG. 9 (b), both ends are in a state of a simple support beam in which both ends are variably supported by spherical bearings 90 and 83, and an intermediate portion thereof is provided. Since the bending moment M is connected to the drive shaft 50 via the universal joint 52, the bending moment M is a maximum value Mmax on the wheel axle.
And gradually decreases upward from this position.
Therefore, the telescopic rod 72 faces upward with the strong cylinder body 71 facing downward.

In the latter case, the cylinder body 71 is fixed to the wheel supporting portion 19 and rotates with the wheel supporting portion 19, so that the oil that passes through the head side chamber and the rod side chamber to the telescopic rod 72 that does not rotate the steering wheel is provided. If a path is formed and a pipe 79 as shown in FIG. 6A is connected to the head side port and the rod side port which are the outer openings, the connection reliability can be improved.

The present invention is not limited to such an embodiment, but may take the following forms as examples.

(1) FIG. 1 and the like show the case where the engine 30 and the transmission 34 are mounted on the rear part of the body frame 12, but the present invention can be applied to the case where these are mounted on the front part. It is. In this case, an installation space for the engine 30 and the transmission 34 is secured by making the front portion of the body frame 12 a branch portion, and the output shaft of the transmission 34 is directly connected to the input shaft of the front differential gear 38. do it.

(2) Although FIG. 1 and the like show a four-wheeled self-propelled crane, in the present invention, for example, a six-wheeled crane may be used regardless of the number of wheels. In this case as well, which wheel the input shaft of the differential device is directly connected to the output shaft of the transmission may be appropriately determined according to the specific structure of the vehicle.

(3) Between the engine 30 and the torque converter 32 and the transmission 34, they may be connected via a drive shaft as in the prior art. However, if a direct connection structure as described above is used, the structure becomes more compact by reducing the distance between the engine / torque converter and the transmission, and the piping connecting the engine and the torque converter to the transmission is shortened to reduce the structure. The advantage that can be simplified is obtained.

The engine 30 has a torque converter 3
In the power transmission system in which the transmission 2 is not connected, the output shaft of the engine 30 and the input shaft of the transmission 34 may be directly connected.

[0047]

As described above, according to the present invention, in a self-propelled crane in which the power of an engine is transmitted to a differential via a transmission, the differential and wheels can be relatively displaced in the vertical direction. As well as the input shaft of this differential and the output shaft of the transmission are directly connected. The number of drive shafts required is reduced, thereby making it possible to reduce the cost of the entire crane, and by reducing the distance between the transmission and the differential, the differential can be removed from the center position in the longitudinal direction of the vehicle body. Thus, there is an effect that a preferable layout can be realized in terms of structural strength and piping and wiring.

[Brief description of the drawings]

FIG. 1 is a side view of a self-propelled crane according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a plan view of an upper swing body of the self-propelled crane.

FIG. 4 is a side view of a power transmission system provided at a rear portion of the self-propelled crane.

FIG. 5 is a skeleton diagram showing an internal structure of the power transmission system.

FIG. 6A is a cross-sectional view showing a modified example of the suspension structure in the self-propelled crane, and FIG. 6B is a bottom view thereof.

FIG. 7 is a sectional view showing a spherical bearing provided in the suspension structure of FIG. 6;

FIG. 8 is a sectional view showing a modification of the suspension structure of the self-propelled crane.

9A is a bending moment diagram for the shock absorbing cylinder shown in FIG. 8, and FIG. 9B is a bending moment diagram for the shock absorbing cylinder shown in FIG.

FIG. 10 is a side view showing an example of a conventional self-propelled crane.

11 is a side view showing a drive transmission system mounted on a rear part of the self-propelled crane according to FIG.

12A is a sectional view taken along line XIIA-XIIA in FIG.
FIG. 11B is a sectional view taken along line XIIB-XIIB in FIG. 10.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Lower traveling body 12 Body frame 16 Branch part 18F, 18R Wheel 20 Upper revolving structure 30 Engine 32 Torque converter 33, 35 Single shaft 34 Transmission (transmission and distribution machine) 36, 38 Differential gear (differential device) ) 50 Drive shaft (transmission shaft) 51, 52 Universal joint

Claims (7)

[Claims] 1. A self-propelled crane in which power of an engine is transmitted to a differential via a transmission, wherein the differential and wheels are connected so as to be vertically displaceable relative to each other. A self-propelled crane, wherein an input shaft of a differential device is directly connected to an output shaft of the transmission. 2. The self-propelled crane according to claim 1, wherein the output shaft of the transmission and the input shaft of the differential are constituted by a single shaft. 3. The self-propelled crane according to claim 1, wherein an output shaft of the engine or an output shaft of a torque converter connected to the output shaft is directly connected to an input shaft of the transmission. Alternatively, a self-propelled crane in which a torque converter is disposed immediately above the differential device. 4. The self-propelled crane according to claim 3, wherein the output shaft of the engine or the output shaft of the torque converter connected to the output shaft and the input shaft of the transmission are formed as a single shaft. A self-propelled crane characterized by the following. 5. The self-propelled crane according to claim 3, wherein a hydraulic pump driven by the power of the engine is disposed at a position in line with the transmission. 6. The self-propelled crane according to any one of claims 3 to 5, wherein a branching portion that branches right and left is formed on a body frame of the crane, and the engine, the transmission, and the branching portion are provided between the branching portions. A self-propelled crane characterized by disposing a differential. 7. The self-propelled crane according to claim 6, wherein the differential device is fixed to the vehicle body frame side, and one end of a transmission shaft extending in a left-right direction to a left-right output shaft of the differential device is variable in relative angle. And the wheels are connected to the other ends of these transmission shafts so that the relative angle can be changed, and the transmission shafts are arranged such that the transmission shafts pass through the respective branch portions in the left-right direction. A self-propelled crane characterized by the following.