JP3488740B2 - Self-propelled crane truck - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-propelled mobile crane used at a construction site or a construction site.

[0002]

2. Description of the Related Art Generally, a large self-propelled mobile crane has an engine for traveling and an engine for crane work, and also has a detachable counterweight for balancing the crane during crane work. There is.

When working on a large site, it may be necessary to move from site to site within the site. When moving on site like this, if the driving engine is not set to a very large one,
Very heavy counterweight needs to be removed. Further, even if the traveling engine can bear the weight of the counterweight, it is not preferable to move the engine with the counterweight attached, because it imposes a great deal of strain on the engine.

However, it is very inefficient to remove the counter weight, which is attached with great care, each time it is moved. Further, depending on the work, it is necessary to move the load while suspending it with a crane, and in this case, it is necessary to carry a counterweight. Therefore, from the point of view of improving work efficiency and ensuring the mobility of the crane, it is extremely convenient to carry out on-site movement with the counter weight attached. In this case, since it moves with a very heavy counterweight attached, it is necessary to increase the driving force accordingly, and it is necessary to increase the engine output.

Therefore, various techniques for increasing the driving force have been conventionally known. For example, Japanese Examined Patent Publication No. 46-30123 discloses a self-propelled crane that drives the drive wheels by adding the output of a crane engine to the output of a traveling engine.

[0006]

However, in the configuration disclosed in Japanese Patent Publication No. 46-30123, only the output of the engine is increased and the number of wheels does not change. Therefore, the weight of the counterweight must be supported by the existing wheels, and if the vehicle is to be run with the counterweight attached, the wheel load will eventually increase. In addition, there is concern about the stability of the traveling vehicle body when moving while the load is suspended.

In order to ensure a stable running even when the load is moved in a suspended state, Japanese Patent Publication Sho 62-946
Japanese Unexamined Patent Publication No. 7 discloses a detachable auxiliary wheel that is grounded when moving on site. Further, this auxiliary wheel can solve the above-mentioned problem of wheel load. However, since the auxiliary wheels are not driving wheels, the driving force becomes insufficient when the vehicle is going to travel with the counterweight attached.

Further, Japanese Patent Application Laid-Open No. 1-285469 discloses an auxiliary wheel which can be driven by itself, but since the auxiliary wheel is not configured to be driven simultaneously with the driving wheel for traveling, In the on-site movement with the load suspended, or the on-site movement with the counterweight mounted, the driving force is still insufficient.

As described above, in the conventional art, the vehicle travels with a stable and sufficient driving force when the load increases, such as an on-site movement with a load suspended or an on-site movement with a counterweight mounted. I couldn't.

The present invention has been made in view of the above circumstances, and an object of the present invention is to sufficiently prevent the engine from being burdened even when the counterweight is mounted and the load is suspended. It is to provide a self-propelled mobile crane that can perform stable traveling with output.

[0011]

In order to solve the above-mentioned problems, the present invention comprises a crane mounted on a swivel provided on a traveling vehicle, and can drive drive wheels provided on the traveling vehicle. A traveling engine and a crane engine capable of driving the crane device separately, and a traveling auxiliary that can be driven simultaneously with the drive wheels driven by the crane engine and driven by the traveling engine. A drive wheel is provided on the traveling vehicle body at a side of the swivel base, and a wheel direction of the traveling auxiliary drive wheel is set at a mounting portion between the traveling auxiliary drive wheel and the traveling vehicle body. It is a self-propelled mobile crane, which is provided with rocking prevention means for restricting it in a traveling direction.

[0012]

In the crane vehicle of the above construction, the output of the traveling engine is supplemented by the crane engine during on-site traveling, so that the engine can be burdened even when traveling under suspended loads where the traveling vehicle body is very heavy. Absent. not only that,
In the case of the above configuration, since the auxiliary drive wheels driven by the crane engine are provided separately from the drive wheels driven by the traveling engine, it is possible to substantially increase the number of drive wheels and reduce the wheel load. It is possible to reduce the number and perform stable driving.

Therefore, in the on-site movement with the counterweight attached or with the load suspended, the corresponding increase in driving force, that is, auxiliary power, can be easily obtained, and the engine load is sufficient. Stable running can be performed with the output. That is, according to the crane vehicle having the above-described configuration, it is possible to easily perform on-site traveling without straining the engine while securing the mobility of the crane.

In addition, the crane engine, which is rarely used when moving on site, is used as auxiliary power for traveling, and the auxiliary drive wheels are driven by this crane engine, that is, the existing device is used. Since it is effectively used, it is not necessary to separately provide an engine for auxiliary drive wheels, and it is possible to prevent the crane vehicle from becoming large in size. Therefore, inconvenient problems in terms of mounting space and cost do not occur.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 schematically shows the overall structure of a self-propelled mobile crane according to an embodiment of the present invention. As shown in the figure, the mobile crane 1 of this embodiment is
Called career. ) 10 and a crane device 12 mounted on the carrier 10. The carrier 10 includes a driver's cab 13 for performing a normal traveling operation. Further, the carrier 10 is provided with a plurality of wheels 15 on both sides thereof. Among these wheels 15, the driven wheel is 15 in the figure.
The drive wheels are shown at 15a and at 15b. And
As shown in detail in FIG. 2, an auxiliary drive wheel 20 to be described later is detachably provided outside the drive wheel 15b in parallel with the drive wheel 15b and overhanging to the side of the carrier 10. The auxiliary drive wheel 20 is, as shown in FIG.
One carrier is provided on each side of the carrier 10.

Outriggers 8 ... Are attached to the front and rear of the carrier 10, respectively. These outriggers 8 ...
Is extended to the side of the carrier 10 through the beam during crane work, and by extending the jack part of the cylinder / piston structure attached to the tip of the beam, the ground plate attached to the lower end of the jack part is extended. The carrier 10 having the crane device 12 is supported by being pressed against the ground.

A swivel base 22 is mounted on a portion of the carrier 10 located just above the drive wheel 15b. A revolving structure 23 having a driver's cab 25 for performing a crane work operation is rotatably mounted on the revolving base 22.

The revolving structure 23 is provided with a counterweight 21 for balancing the crane vehicle 1 during crane work. Further, the telescopic boom 5 is attached to the revolving structure 23 so as to be capable of undulating. The telescopic boom 5 is composed of a plurality of stages of booms that are telescopically connected, and can be extended by a telescopic cylinder (not shown). And revolving structure 2
A hoisting cylinder is bridged between 3 and the lower surface of the base end side boom, and the hoisting cylinder hoists and retracts the telescopic boom 5. Further, a winch (not shown) is provided on the revolving structure 23, and the wire 7 is wound or unwound by the winch. The wire 7 delivered from the winch is wound around a sheave rotatably attached to the boom 5 and hung from the tip of the boom 5. A lifting hook 9 is suspended on the suspended wire.

Therefore, when the wire 7 is wound by the winch while maintaining the extended posture and the raised / lowered posture of the telescopic boom 5, the lifting hook 9 rises toward the tip of the boom 5. Also, when the wire 7 is paid out by the winch,
The lifting hook 9 descends so as to separate from the tip of the boom 5. Therefore, a crane operation can be performed by hooking the luggage 30 on the lifting hook 9.

Next, the connection structure between the carrier 10 and the auxiliary drive wheels 20 will be described in detail. As shown in FIG.
Extension parts 32, 32 extending laterally of the carrier 10 are provided on both sides of a swivel base 22 as a swivel bearing provided on the carrier 10. A beam 34 is detachably attached to the tip of each extension 32. That is, as shown in FIG. 3B, two mounting portions 36, 36 (see FIG. 7) are provided on the lower surface of the beam 34 in a protruding manner, and the mounting receiving portion is also mounted on the lower surface of the extending portion 32. 38
Is projected. Then, as shown in FIG. 7, the mounting receiving portion 38 is positioned so as to be sandwiched by the two mounting portions 36, 36 from both sides.
The pin 37 is inserted into the mounting hole of the mounting hole 36 and the mounting hole of the mounting receiving portion 38. Also, in this state,
Rod-shaped engaging members 35a, 35b provided on the beam 34
Is engaged with, for example, a groove-shaped engaging portion provided in the extending portion 32. That is, the engaging members 35a and 35b are connected to the extension portion 32.
When the mounting portions 36, 36 and the mounting receiving portion 38 are fixed by the pin 37 in a state where the beam 34 and the extending portion 32 are engaged with each other, the beam 34 is surely attached to the extending portion 32. Fixed.

When removing the beam 34 from the extension 32, hold the handle 37a of the pin 37 and hold the pin 3 in place.
When the beam 7 is pulled out and the beam 34 is pulled out in the longitudinal direction of the extending portion 32, the engaging members 35a and 35b with respect to the extending portion 32 are formed.
Is disengaged and the beam 34 is separated from the extension 32 of the swivel base 22, that is, the carrier 10 side.

A jack portion 42 is attached to the tip of the beam 34. The jack portion 42 is composed of a hydraulic cylinder 42a and a hydraulically actuated piston 42b (see FIG. 4A). As shown in FIG. 3B with respect to a mounting portion 45 at the tip of the piston 42b. Ground plate 50
Can be detachably attached, or the auxiliary drive wheel 20 can be detachably attached as shown in FIG. When the ground plate 50 is attached to the tip attachment portion 45 of the piston 42b as shown in FIG. 3B, the jack portion 42 functions as an outrigger as described later. In addition, as shown in FIG.
When the auxiliary drive wheel 20 is attached to the tip attaching portion 45 of 2b, the jack portion 42 functions as a suspension as described later.

As shown by the chain double-dashed line in FIG. 4A, with the auxiliary drive wheel 20 attached to the tip of the piston 42b, the lower part of the auxiliary drive wheel 20 (the auxiliary drive wheel described in detail later) It is also possible to attach the ground plate 50 to the lower part of the axle beam 48 of 20).

As shown in FIG. 4A, the auxiliary drive wheel 2
No. 0 is configured such that two drive-side wheels 51 as double tires and two driven-side wheels 52 as double tires are attached to both sides of an axle beam 48 that constitutes an auxiliary drive wheel main body. Two driving wheels 51
An integral unit composed of a speed reducer 54 and a hydraulic motor 53 is coaxially directly connected to. In this case, the speed reducer 54
Is disposed inside the wheel 51, and the hydraulic motor 53 is housed between the wheels 51 and 51, that is, inside the wheel. The details of the hydraulic circuit including the hydraulic motor 53 will be described later.

As shown in FIG. 6, the axle beam 48 constituting the main body of the auxiliary drive wheel 20 has a shape in which the letter V is widened outward, and the axle beams 56 of the driven wheels 52, 52 are provided on both sides thereof. The drive side wheels 51, and the flange 57 of the 51 are attached. The flanges 57 of the drive wheels 51, 51 are provided with a mounting hole 58 for mounting an integrated unit including the speed reducer 54 and the hydraulic motor 53, and a large number of screw holes 59 into which mounting screws are screwed. Has been.

Further, a hemispherical fitting hole 61 into which the tip mounting portion 45 of the piston 42a of the jack portion 42 is fitted is formed on the upper surface of the axle beam 48 substantially in the center thereof. The tip end spherical portion of the mounting portion 45 of the piston 42a is fitted into the fitting hole 61 and is fixed by a fixing member (not shown), so that the tip end of the piston 42a is attached to the axle beam 48. In addition, a mounting hole 62 for fitting the ground plate 50 and mounting it with a pin (not shown) is formed on the lower surface of the center portion of the axle beam 48.

As shown in FIG. 5, a stay 67 extends from the substantially central portion of the axle beam 48 perpendicularly to the longitudinal direction of the axle beam 48. A receiving member 68 is provided at the tip of the stay 67, and a rod-shaped restricting member 40 (see FIG. 3B) vertically protruding from the lower surface of the beam 32 is fitted into the receiving member 68. An insertion hole 69 to be inserted is formed. The restriction member 40 and the stay 6
The receiving member 68 of 7 constitutes a swing preventing mechanism for preventing the swing of the auxiliary drive wheel 20, and when the auxiliary drive wheel 20 is assembled to the carrier 10 via the jack portion 42 and the beam 34. 8, connected to each other in the state shown in FIG. 8 to perform a rocking preventive function for restricting the direction of the wheels of the auxiliary drive wheels 20 in the longitudinal direction of the carrier 10, and to rotate the cylinder 42a having a seal structure weak against rotation. Prevents directional forces from acting.

By the way, the mobile crane 1 of the present embodiment is equipped with a crane engine used during crane work in addition to the traveling engine, and the auxiliary drive wheels 20 having the above-described structure are driven by the power of the crane engine. Driven. The configuration is schematically shown in FIG.

As shown, the carrier 10 is provided with a running engine 100. Running engine 100
Is driven by the drive wheel 15 via the propeller shaft 101.
Then, the driving wheel 15b is rotated and driven. Also,
The revolving structure 23 is provided with an engine 102 dedicated to the crane and a hydraulic pump 79 driven by the crane engine 102. This hydraulic pump 79 has a drive side wheel 51 of the auxiliary drive wheel 20 via a hydraulic pipe 104.
Is connected to a hydraulic motor 53 provided in the. Therefore, the hydraulic engine 1 is operated by the crane engine 102.
When 03 is driven, oil is sent to the hydraulic motor 53 via the pipe 104, and the hydraulic motor 53 is driven. As a result, the drive side wheels 51 of the auxiliary drive wheels 20 are rotationally driven.

An electromagnetically operated directional control valve 75 is provided in the middle of the hydraulic pipe 104. This directional valve 7
5 is switched by a switching signal of a forward / backward changeover switch 86 (installed in the cab 13) for controlling forward / backward movement of the auxiliary drive wheel 20. Therefore, the electric lines indicated by B and C in the figure are the forward / reverse selector switches 8
6 and the directional control valve 75 are electrically connected. When the direction switching valve 75 is switched by the forward / reverse switching switch 86, the direction of oil flow through the hydraulic pipe 104 is switched, and the hydraulic motor 53 is rotated forward / reversely, so that the drive-side wheel 51 of the auxiliary drive wheel 20 moves forward. It is rotated or rotated backward.

A hydraulic circuit is shown in FIG. In the figure, the hydraulic motor drive circuit 130 for driving the hydraulic motor 53 described above, and the jack portion 4 as a hydraulic cylinder.
A suspension circuit 131 that operates 2 to cause the jack portion 42 to function as a suspension of the auxiliary drive wheel 20, and an outrigger circuit that causes the jack portion 42 to operate to cause the jack portion 42 to function as an outrigger. And 132 are shown.

First, the hydraulic motor drive circuit 130 will be described. The hydraulic motor drive circuit 130 is provided with the hydraulic pump 79 driven by the above-described crane engine 102 and the hydraulic pipe 104 for sending the oil discharged by the hydraulic pump 79 toward the hydraulic motor 53. As described above, the direction switching valve 75 is provided in the middle of the hydraulic pipe 104. This directional valve 75
Is a neutral position for sending oil toward a crane circuit for driving the crane device, a forward rotation position for sending oil in a forward direction for operating the hydraulic motor 53 so that the auxiliary drive wheel 20 drives forward, and the auxiliary drive wheel 20. Can be switched to a reverse rotation position in which oil is fed in the reverse rotation direction in which the hydraulic motor 53 is operated so as to drive backward.

The switching operation of the direction switching valve 75 is performed by the forward / reverse switching switch 86 described above. The forward / backward changeover switch 86 has a forward / backward changeover circuit 86a shown by a chain line in the figure. FIG. 11 shows details of the forward / reverse switching circuit 86a.

According to the forward / reverse switching circuit 86a shown in FIG. 11, the auxiliary drive wheels 20 can be driven forward or backward by either automatic or manual operation. Therefore, the forward / reverse switching circuit 86a is provided with an automatic / manual switching switch 92. An electric line (a) connected to the power source on the carrier 10 side is connected to the automatic / manual changeover switch 92 through an electric line 98,
When the operator switches the automatic / manual switch 92 to automatic, the automatic mode is set. In this automatic mode,
When the operator sets the transmission to low (low speed gear), the detection means (not shown) detects this and the mission switch 9
1 is turned on. As a result, the electric line 98 is electrically connected to the first automatic mode electric line 93 via the automatic / manual changeover switch 92 and the mission switch 91. Therefore, the control signal accompanying this is sent to the direction switching valve 75 via the electric line (b), and the direction switching valve 75 is switched to the normal position described above. This allows
The auxiliary drive wheel 20 is rotationally driven in the forward direction.

Further, in this automatic mode, when the operator sets the transmission to the back, the signal of the back lamp 90 is transmitted to the second automatic mode electric line 95 via the signal line 94 and the automatic / manual changeover switch 92. Sent. Then, this signal is sent to the directional control valve 7 via the electric line (C).
5 to switch the directional control valve 75 to the above-mentioned reverse rotation position. Therefore, the auxiliary drive wheel 20 is rotationally driven in the backward direction.

On the other hand, when the operator switches the automatic / manual switch 92 to manual, the manual mode electric line 99 and the electric line 98 are electrically connected and the manual mode is set. In this manual mode, when the operator switches the manual switch 93 to the forward position, the manual mode electric line 99 and the electric line 97 are electrically connected. Therefore, the control signal accompanying this is sent to the direction switching valve 75 via the electric line (b), and the direction switching valve 75 is switched to the normal position. As a result, the auxiliary drive wheel 20 is rotationally driven in the forward direction.

When the operator switches the manual switch 93 to the reverse position, the manual mode electric line 99 and the electric line 96 are electrically connected. Therefore, the control signal accompanying this is sent to the directional control valve 75 via the electric line (C).
And the direction switching valve 75 is switched to the reverse rotation position.
As a result, the auxiliary drive wheel 20 is rotationally driven in the backward direction.

On the other hand, the hydraulic motor 53 is provided on the two drive wheels 51, 51 of the auxiliary drive wheel 20 as described above, and one auxiliary drive wheel 20 is provided on each side of the carrier 10. Therefore, a total of four hydraulic motors 53 are installed. Therefore, four hydraulic motors 53 are shown in the hydraulic circuit shown in FIG.

Four hydraulic circuits 105 (105a, 105a, 105b, 105) arranged on the auxiliary drive wheel 20 side
Each of b) is detachably connected to the hydraulic pipe 104 via a coupler 71. As shown, the four hydraulic circuits 105 are connected in parallel with each other. That is, the hydraulic circuits 105a, 105a of the auxiliary drive wheels 20 mounted on one side of the carrier 10 and the hydraulic circuits 105b, 105b of the auxiliary drive wheels 20 mounted on the other side of the carrier 10.
Are connected in parallel with each other, and the hydraulic circuit 105
a, 105a and hydraulic circuits 105b, 105b are also connected in parallel with each other.

Next, the suspension circuit 131 that causes the jack portion 42 to function as the suspension of the auxiliary drive wheel 20 will be described. The suspension circuit 131 includes the above-described crane engine 102.
Hydraulic pump 81 driven by
The oil discharged by the cylinder 4 of the jack 42
A hydraulic pipe 150 for sending into 2a is provided. A direction switching valve 77 is provided in the middle of the hydraulic pipe 150. The direction switching valve 77 can switch between a crane position that sends oil toward the crane circuit that drives the crane device 12 and a cylinder position that sends oil toward the inside of the cylinder 42a. The switching operation of the direction switching valve 77 is performed by the suspension switch 80 provided in the cab 13 of the carrier 10. That is, when the operator turns on the suspension switch 80, the direction switching valve 77 switches to the cylinder position, and the oil from the hydraulic pump 81 is supplied into the hydraulic cylinder 42a.

On the other hand, the hydraulic pipe 152 arranged on the side of the jack portion 42 is detachably connected to the hydraulic pipe 150 via the coupler 71. A branch pipe 171 having a relief valve 170 is connected in the middle of the hydraulic pipe 150. As a result, for example, the weight of the vehicle body is maintained in the hydraulic pipe 150 at a constant pressure that can support the weight of the vehicle body in cooperation with other wheels. As a result, the pressing force of the piston 42b that presses the auxiliary drive wheel 20 downward can maintain the ground output of the auxiliary drive wheel 20 at least to such an extent that the vehicle body is not lifted. Therefore, the jack portion 42 is
The function as a suspension is sufficiently fulfilled, and an excessive load is not applied to the auxiliary drive wheels 20. A branch pipe 72 communicating with, for example, the accumulator 70 is connected in the middle of the hydraulic pipe 152. Accumulator 70
Is installed on the side of the beam 34, for example, as shown in FIG.

Next, the outrigger circuit 132 that causes the jack portion 42 to function as an outrigger will be described. The outrigger circuit 132 is provided with a hydraulic pump 82 and a hydraulic pipe 161 for sending the oil discharged by the hydraulic pump 82 into the cylinder 42a of the jack portion 42. Since the crane engine 102 is used to drive the crane device 12 when the jack portion 42 is used as an outrigger, the hydraulic pump 82 is driven by the traveling engine 100.

A direction switching valve 76 is provided in the middle of the hydraulic pipe 161. The direction switching valve 76 sends the oil to the hydraulic circuit for traveling and the piston 42b.
Neutral position to maintain the protruding position of the piston 4
It is possible to switch between an extruding position for sending oil in the direction of pushing out 2b and a retracting position for sending oil in the direction of retracting the piston 42b into the cylinder 42a. Such a switching operation of the direction switching valve 76 is performed by a switching switch (not shown).

Further, the hydraulic pipe 160 arranged on the jack portion 42 side is detachably connected to the hydraulic pipe 161 via a coupler 71. The hydraulic pipe 161 is provided with a check valve 85 for maintaining the protruding position of the piston 42b and maintaining the ground output as an outrigger. The check valve 85 is opened by a pilot signal when the piston 42b is pulled back into the cylinder 42a.

As described above, the crane vehicle 1 of this embodiment is provided with the crane engine 102 in addition to the traveling engine 100.
The auxiliary drive wheel 20 driven by the power of 2 can be detachably attached to the carrier 10.

Therefore, during normal road traveling, the traveling engine 1 is operated in a lightweight state with the auxiliary drive wheels 20 removed.
The vehicle can be driven by the drive wheels 15b driven by 00, and the auxiliary drive wheels 20 are attached to the crane engine 1 when moving from site to site in a large site.
The auxiliary drive wheel 20 driven by the power of 02 and the drive wheel 15b driven by the traveling engine 100 can perform on-site traveling.

It is desirable from the standpoint of work efficiency that the counterweight 21 is mounted without removing the counterweight 21 while traveling on site. In particular, when the on-site traveling is performed with the load being suspended by the crane device (the state shown in FIG. 1), the counterweight 21 needs to be mounted. As described above, it is very difficult to drive only the traveling engine 100 when the carrier 10 is heavily loaded.
It will be a great burden to

However, the mobile crane 1 of this embodiment
Is used by the crane engine 102 to supplement the output of the traveling engine 100 during traveling on site.
No heavy load is applied to the engine even when traveling with a suspended load that requires a large amount of weight. Not only that, but in the case of the present embodiment, since the drive wheels 15b driven by the traveling engine 100 are provided with the drive wheels 20 driven by the crane engine 102, the number of drive wheels is substantially reduced. The number of wheels can be increased and the wheel load can be reduced to allow stable traveling.

Therefore, when the counter weight 21 is attached or the load is suspended in the field, a corresponding increase in driving force, that is, auxiliary power can be easily obtained, and the engine is not burdened. It can run with various outputs.

That is, according to the mobile crane 1 of the present embodiment, it is possible to easily perform on-site traveling without straining the engine in a state where the mobility of the crane is secured, and to carry out normal road traveling. , Auxiliary drive wheel 20
Can be removed to reduce the weight.

The crane engine 102, which is rarely used when moving on site, is used as auxiliary power for traveling, and the auxiliary drive wheels 20 are driven by this engine 102.
Is used, that is, because the existing device is effectively used, it is not necessary to separately provide a drive engine for the auxiliary drive wheels 20, and it is possible to prevent the crane vehicle 1 from becoming large in size. be able to. Therefore, inconvenient problems in terms of mounting space and cost do not occur.

In the mobile crane 1 of this embodiment, the auxiliary drive wheels 20 are not steered, that is, the drive wheels 1.
Since it is provided in the vicinity of 5b, specifically on the left and right of the carrier 10 in parallel with the drive wheels 15b, a steering device for the auxiliary drive wheels 20 is not necessary, and the auxiliary drive wheels 20 hardly slip.

Furthermore, in the mobile crane 1 of this embodiment, the auxiliary drive wheels 20 can be automatically operated in association with the low speed or reverse operation of the transmission. As described above, the on-site movement performed with the weight suspended and the carrier weight mounted is usually performed at a low speed (it is impossible at a high gear position). Therefore, automation can be easily achieved by setting the auxiliary drive wheels 20 to move forward with the low speed gear (low gear).

Further, the mobile crane 1 of this embodiment is provided with a swing preventing mechanism for preventing swing of the auxiliary drive wheels 20.
That is, the direction of the wheels of the auxiliary drive wheels 20 can be restricted in the longitudinal direction of the carrier 10 by the restriction member 40 and the receiving member 68 of the stay 67. Therefore, stable running can be obtained even when the auxiliary drive wheels 20 are used.

On the other hand, the four hydraulic circuits 105a for driving the auxiliary drive wheels 20 of this embodiment are connected in parallel with each other. In a general vehicle, a non-steered wheel is provided with a differential gear, but in the present embodiment, four hydraulic circuits 105a are connected in parallel with each other, and therefore, due to hydraulic characteristics, when the crane vehicle is turning. If resistance is applied to either the left or right wheel of the carrier 10, this wheel rotates at low speed and the wheel on the other side rotates at high speed, and the hydraulic circuit itself functions as a differential gear.

Further, in this embodiment, since the hydraulic motor 53 is housed between the wheels 51, that is, inside the wheels, the hydraulic motor 53 does not project to the side of the wheels, and the double tire is substantially used. Will be possible.

Further, in the present embodiment, the jack portion 42 of the cylinder / piston structure is connected to the relief valve 170 so that the weight of the vehicle body is maintained at a constant pressure that can be supported in cooperation with other wheels, and the suspension is maintained. It has the function as. Furthermore, when traveling, the relief valve 17
With 0, the auxiliary drive wheel 20 is constantly adjusted by the jack portion 42 so that the ground output thereof does not lift the vehicle body at least by itself. Therefore, it is possible to prevent the auxiliary drive wheel 20 from being damaged due to overload.

Further, a ground plate can be attached to the lower end of the jack portion 42 of the cylinder / piston structure. Therefore, the jack portion 42 can function as an outrigger during crane work. In particular, the jack portion 42
Since the crane device is installed in the part where
The largest deflection. Therefore, providing an outrigger at this portion is extremely useful for performing stable work.

The running engine 100 is usually
It is connected to the pump via the TO. In this case, the PTO is also turned on and off when the clutch is turned on and off, so that stable pump drive cannot be obtained. Therefore, in the present embodiment, the jack portion 42 is connected to the hydraulic pump 81 driven by the crane engine 102 in order to obtain a stable pump drive and a stable suspension function.

Further, in this embodiment, the auxiliary drive wheel 20 is used.
Is merely detachably attached, but the auxiliary drive wheel 20 is attached to the carrier 10 so as to be able to move up and down so that the position of the auxiliary drive wheel 20 can be changed between a grounded state and a non-grounded state. It may be. Needless to say, the present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the scope of the invention.

[0061]

As described above, according to the self-propelled mobile crane of the present invention, sufficient output can be obtained without burdening the engine even when the counterweight is mounted and the load is suspended. Can run stably

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a mobile crane according to an embodiment of the present invention.

FIG. 2 is a plan view of a carrier portion of the mobile crane of FIG.

3A is a plan view of an auxiliary drive wheel connecting portion installed in a swivel base portion of the crane vehicle of FIG. 1, and FIG. 3B is a side view of FIG.

4A is a front view of an auxiliary drive wheel attached to a jack portion of a cylinder / piston structure, and FIG. 4B is a sectional view showing an internal structure of a drive side wheel of the auxiliary drive wheel.

5A is a plan view of an auxiliary drive wheel main body for mounting wheels, and FIG. 5B is a sectional view taken along line BB of FIG. 5A.

6 is a side view of the auxiliary drive wheel body of FIG.

7 is a cross-sectional view taken along the line AA of FIG. 3 (b).

FIG. 8 is a perspective view showing a state in which auxiliary drive wheels are attached to the carrier.

FIG. 9 is a schematic diagram schematically showing a hydraulic circuit that drives an auxiliary drive wheel and a drive wheel.

FIG. 10 is a circuit diagram of a hydraulic circuit that drives auxiliary driving wheels and a jack portion.

FIG. 11 is an electric circuit diagram for electrically controlling a directional control valve provided in a hydraulic circuit of auxiliary drive wheels.

[Explanation of symbols]

1 ... mobile crane, 10 ... carrier (driving vehicle), 12 ...
Crane device, 15b ... drive wheels, 20 ... auxiliary drive wheels, 4
2 ... jack part, 100 ... running engine, 102 ... crane engine.

Claims (4)

(57) [Claims] 1. A traveling engine equipped with a crane device mounted on a swivel provided on a traveling vehicle body and capable of driving drive wheels provided on the traveling vehicle body, and a crane engine capable of driving the crane device. And a driving auxiliary drive wheel that is separately provided and is capable of being driven simultaneously with the drive wheels driven by the crane engine and driven by the traveling engine. And a rocking preventing means for restricting the wheel direction of the traveling auxiliary drive wheel in the traveling direction of the traveling vehicle body is provided at a mounting portion between the traveling auxiliary drive wheel and the traveling vehicle body. Mobile crane. 2. The self-propelled mobile crane according to claim 1, wherein the traveling auxiliary drive wheels are detachably attached to the traveling vehicle body. 3. The self-propelled mobile crane according to claim 1, wherein the traveling auxiliary drive wheels are provided in the vicinity of wheels which are not steered. 4. The traveling auxiliary drive wheel is attached to the traveling vehicle body through a hydraulically operated jack portion having a piston / cylinder structure, and is vertically movable in accordance with the amount of movement of the piston of the jack portion. The self-propelled mobile crane according to claim 1 or 3, wherein