JPH09301682A - Boom head housing mechanism of mobile crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To house a boom head in the side of a boom, further ensure sufficiently the front view of field from a cab in the housing and provide sufficiently large approach angle. SOLUTION: In a boom head housing mechanism of a mobile crane for housing the boom head 25 provided on the tip of a boom 18b to be pivoted to the boom 18b in the side of the boom 18b are provide a pivot 35 having the upper end inclined toward the tip side of the boom 18b to make a predetermined angle θ to the axis Z perpendicular to the longitudinal axis of the boom 18b, while pivotably supporting the boom head 25, and pivotal means 65, 68a, 68b to pivot the boom head 25 about the pivot 35.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boom head retracting mechanism for retracting a boom head provided at the tip of a boom of a self-propelled crane to the side of the boom.

[0002]

2. Description of the Related Art Generally, a self-propelled crane is provided with a telescopic boom. As shown in (a) of FIG. 7, the boom 102 is movably attached to a revolving structure 101 that is rotatably mounted on a vehicle body 100 of a self-propelled crane, and is mounted by a telescopic cylinder (not shown). It is designed to be expanded and contracted.

A boom head 103 having a plurality of sheaves 107 for hanging a wire 106 on the tip of the boom 102 to suspend the wire 106.
Is protruding. Generally, the boom 102 is in a state of protruding from the front end of the vehicle body 100 even when the boom 102 is retracted and stored. Therefore, the total length L of the crane vehicle is equal to the boom 1
The size of the boom head 103 protruding from the end of 02,
That is, it is determined by the protruding length of the boom head 103 protruding forward from the tip of the boom 102.

The boom head 103 has a plurality of sheaves 1 such as sheaves for winding multiple ropes and auxiliary sheaves for single rope work.
Because of the necessity of arranging 07 ..., In general, they protrude below the lower surface of the boom 102. Therefore, particularly in the case of a self-propelled crane that travels with the tip end side of the boom 102 tilted downward as shown in FIG. The angle α formed by the straight line connecting the ground contact portion with the ground 105 (hereinafter, this angle α is referred to as the approach angle) is the boom head 1.
It is determined by the position and size of 03.

[0005]

Such a boom head 103 protruding forward from the tip of the boom 102 extends the effective length of the boom 102, and as described above, the total length L of the crane vehicle and the approach angle α. Is a component that can specify

Therefore, even if the boom head 103 increases the effective length of the boom 102, the boom head 103 is placed in front of the vehicle body 100, that is, the boom 10.
If it extends too far in front of 2, there is a risk that the boom head 103 will collide with a preceding vehicle or an obstacle when the crane moves. In particular, at a narrow bend in the road, the boom head 103 easily interferes with an obstacle, which may impair smooth running.

The boom head 103 is attached to the boom 102.
If you push it downwards from the bottom of the boom,
In a self-propelled crane that travels with the tip end of 02 tilted downward, the approach angle α becomes small, and the boom head 103 interferes with the sloped surface of the slope when climbing, and the climbing is not possible. May be disturbed.

Therefore, in Japanese Utility Model Laid-Open No. 56-162289, it is possible to avoid interference with obstacles by increasing the effective length of the telescopic boom 102 and shortening the total length L of the crane vehicle as much as possible during traveling. In addition, the boom head 103 is rotated to be stored on the side of the boom 102. That is, as shown in (b) of FIG. 7, the boom head 103 is located in a state of being projected from the tip of the boom 102 as shown by a chain double-dashed line in the figure when in use.
During traveling of the crane, it is rotated and stored on the side of the boom 102 as shown by the solid line in the figure.

However, in Japanese Utility Model Laid-Open No. 56-162289, the boom head 103 projects downward from the lower surface of the boom 102 even when the boom head 103 is stored laterally of the boom 102. There is. Therefore, the visibility from the front of the driver's cab is poor, and particularly in the case of a self-propelled crane that travels with the tip end side of the boom 102 tilted downward, the approach angle α can be set large. difficult.

The present invention has been made by paying attention to the above circumstances, and an object of the present invention is that the boom head can be retracted to the side of the boom, and the front view from the driver's cab can be stored when the boom head is retracted. (EN) It is possible to provide a boom head retracting mechanism for a self-propelled crane that can be sufficiently secured and can have a sufficiently large approach angle.

[0011]

In order to solve the above-mentioned problems, the present invention relates to a self-propelled crane in which a boom head provided at the tip of the boom is rotated with respect to the boom to be stored on the side of the boom. In the boom head storage mechanism of No. 2, the boom is fixed to the tip of the boom, and the upper end of the boom head is inclined toward the tip of the boom so as to form a predetermined angle with the axis perpendicular to the longitudinal axis of the boom. It comprises a rotating shaft for rotatably supporting the boom head, and rotating means for rotating the boom head about the rotating shaft.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a wheel crane (rough terrain crane) 1. The wheel crane 1 includes a combined operation cab (hereinafter referred to as a cab) 14 that can perform both crane work and traveling operation, and travels with the boom 18 tilted to a lower side of the cab 14 to travel. You can As a result, a sufficient lateral field of view can be ensured during traveling, and the center of gravity of the vehicle body can be lowered, so that the stability of the vehicle body during traveling can be improved.

The wheel crane 1 is also provided with a carrier 10 as a traveling vehicle body, and a swivel base 12 is mounted on the carrier 10. A revolving structure 16 having a cab 14 and a telescopic boom 18 is mounted on the revolving base 12.
Is rotatably mounted. In this case, telescopic boom 1
8 is composed of a plurality of stages of booms connected to each other in an extendable and contractible manner, and can be extended by an extendable cylinder (not shown). It is designed to be undulated.

Outriggers 26 are attached to both front and rear sides of the carrier 10. These outriggers 26 project a beam to the side of the carrier 10 during crane work, and a cylinder attached to the tip of the beam.
By extending the jack portion 26a of the piston structure, the ground plate attached to the lower end of the jack portion 26a is pressed against the ground to support the carrier 10.

A winch (not shown) is provided on the revolving structure 16, and the wire 22 is provided by the winch.
Are wound up or unwound. The wire 22 drawn out from the winch is the boom 1
8 (The most advanced boom 18 located at the most tip side in the extended state)
After being engaged with the upper first sheave 32 attached to the boom head 25 located at the tip of b), the lower second sheave 33 also attached to the boom head 25 and the load hanging hook are attached. A multi-line winding is performed between the sheave of a hook block (not shown) that is provided, and the load hanging hook can be hung vertically from the tip of the boom 18. It should be noted that in the state shown in FIG. 1, the boom head 25 is stored by the boom head storage mechanism, which will be described later, until the tip of the boom head 25 faces the base end side of the boom 18 and is stored laterally of the boom 18. ing.

A sheave bracket 15 having an auxiliary sheave 34 is preferably provided at the tip of the boom head 25 so as to be capable of projecting and retracting. Therefore, particularly during light load crane work, it is possible to carry out the single rope crane work with a high hoisting speed by hanging the separate rope ropes hung on the first sheave 32 of the boom head 25 around the auxiliary sheave 34. Becomes

A jib 60 for supplementing the length of the telescopic boom 18 is stored on the side surface of the base end side boom 18a. The jib 60 is composed of a pair of leg portions 61, 61 connected by a plurality of connecting portions.
Reference numeral 61 extends in a bifurcated shape toward the base end side of the jib 60. That is, the jib 60 is formed in a taper shape from the base end side toward the tip end side, and has a substantially flat V shape as a whole.
It is shaped like a letter (ladder). And the jib 60
It is stored in a fixed state along the side surface of the boom 18 (18a) in a state in which the base end side is directed to the tip end side of the boom 18 and the legs 61, 61 are horizontally positioned with respect to each other. ing.

The sheave shafts 33a, 33a of the second sheave 33 are projected on both sides of the boom head 25, and the jib 60 has a leg portion 61, 61 whose tip ends (jib 6).
The concave engaging portions 62, 62 formed at the base end (0) are extended to the tip of the boom 18 while being engaged with the sheave shafts 33a, 33a (see FIG. 2). In the state shown in FIG. 1, the jib 60
Is shown in a state where it is moved from the retracted position along the side surface of the boom 18 to the tip end side of the boom 18 and the engaging portions 62, 62 thereof are engaged with the sheave shafts 33a, 33a.

As shown in FIGS. 2 to 4, the boom head 25 is attached to the most advanced boom 18b so as to be rotatable about a rotation shaft 35. Specifically, the rotating shaft 35
Is fixed to the side end of a tip member 49 provided at the tip of the most advanced boom 18b in a state of being inclined toward the front of the boom 18, and the tip of the boom head 25 is located at the base end side of the boom 18. When rotating the rotation shaft 35 so as to face the boom 18 and positioning it on the side of the boom 18, the boom head 25
A predetermined angle θ is set with respect to the straight line Z perpendicular to the longitudinal axis direction of the boom 18 so that the tip of the boom is directed obliquely upward with respect to the longitudinal axis direction of the boom 18 (in the state of FIG. 1). I am doing it. Then, with respect to the rotating shaft 35, the connecting portion 2 provided at one end of the base end of the boom head 25.
5a is rotatably attached.

In order to rotate the boom head 25 about the rotating shaft 35, a hydraulic cylinder 65 is provided inside the most advanced boom 18a. This hydraulic cylinder 65
Operates the link mechanism 68 connected to the boom head 25 to rotate the boom head 25 about the rotation shaft 35.

As specifically shown in FIG. 3, which is a view taken along the line A--A of FIG. 2, the connecting portion 2 is provided at the base end of the boom head 25.
A bracket 90 is provided inside 5a, and the bracket 90 and the hydraulic cylinder 65 are connected by a link mechanism 68. Specifically, the link mechanism 68
Is a long rectangular first link 68a whose one end is rotatably connected to the bracket 90 of the boom head 25 through a swivel shaft 91, and a swivel shaft 92 is provided at the other end of the first link 68a. The second link 68b has a substantially triangular second link 68b, one end of which is rotatably connected to the other end of the second link 68b, and the other end of the second link 68b supports the hydraulic cylinder 65.
9 is rotatably connected via a swivel shaft 93. The rod portion of the hydraulic cylinder 65 is connected to the middle portion of the second link 68b via the turning shaft 94. In this case, the turning shafts 92, 93, 94 are located near the vertices of the triangle of the second link 68b.

Therefore, the rotary shaft 35 and the hydraulic cylinder 6
According to such a boom head storage mechanism including the link mechanism 68 and the link mechanism 68, when the hydraulic cylinder 65 is extended from the state of the dashed line in FIGS. The boom head 25 is pushed forward, and the boom head 25 is rotated about the rotation shaft 35.
Rotates. Then, when the rod portion of the hydraulic cylinder 65 is extended by a predetermined amount, the link mechanism 68 is fully extended, and the boom head 25 is in a state in which its tip is directed toward the base end side of the boom 18 and the length of the boom 18 is long. The boom 18 is stored on the side of the boom 18 in a state of being directed obliquely upward with respect to the axial direction (a state shown by solid lines in FIGS. 1 and 4).

From this stored state, the hydraulic cylinder 65
When the boom head 25 is pulled toward the tip side of the boom 18 via the link mechanism 68 by contracting the rod portion of the boom head 25, the boom head 25 rotates about the rotation shaft 35 to reach the tip of the most advanced boom 18b. The boom head 25 is located (indicated by a chain line in FIGS. 2, 3, and 4). In this state,
When the fixing pin 51 is inserted into, for example, the fixing hole 53 provided at the other end of the boom head 25, the boom head 25 is fixed in a state of protruding to the tip of the most advanced boom 18b. Note that the hydraulic cylinder 65 and the link mechanism 68 are not shown in FIG. 4 for simplicity.

Further, when the boom head 25 is rotated about the rotating shaft 35 inclined forward of the boom 18 as described above, the boom head 25 is moved to the most advanced boom 18b.
In the state in which the boom head 25 projects to the tip end of the boom head 25, the tip end of the boom head 25 is directed obliquely downward with respect to the longitudinal axis direction of the boom 18. Therefore, when the jib 60 is also attached with its engaging portions 62, 62 engaged with the sheave shafts 33a, 33a of the second sheave 33, as shown by the alternate long and short dash line in FIG. It will be oriented obliquely downward with respect to the axial direction. Therefore, depending on the length, the tension rod 70 that connects the tip of the jib 60 and the tip of the boom head 25 and exerts a projecting tension on the jib 60 is located near the first sheave 32 depending on the length. It becomes impossible to connect to the part of the boom head 25.

Therefore, in this embodiment, a separate fixing link body 75 is provided in the boom head 25 so as to be capable of projecting and retracting, and one end of the tension rod 70 can be fixed to this fixing link body 75. That is, the fixing link body 7
5 indicates three link portions 75, as indicated by a chain double-dashed line in the figure.
a, 75b, 75c. One end of the first link portion 75a is rotatably attached to a portion of the boom head 25 located near the second sheave 33. The other end of the first link portion 75a is provided with a first fixing portion 82 to which one end of the tension rod 70 is detachably fixed. At the other end of the first link portion 75a, an extension portion 59 that extends laterally from here is formed, and at the extension portion 59, one end of the second link portion 75b is provided via the swivel shaft 83. Are rotatably connected. Second link part 75
The other end of b is connected to the third link portion 75 via the turning shaft 85.
It is pivotally connected to a portion near one end of c. A second fixing portion 84, which is detachably fixed to the support body 55 fixed to the boom head 25, is provided at one end of the third link portion 75c located near the swivel shaft 85. Further, the other end of the third link portion 75c is connected to the first sheave 32
Is rotatably connected to the sheave shaft 86.

The second fixing portion 84 is formed, for example, as a pin insertion hole, and this pin insertion hole and the support member 5, for example.
By inserting the fixing pin 58 into the insertion hole of No. 5, the fixing link body 75 is held in the contracted storage state shown by the chain double-dashed line in the figure. Further, when the fixing link body 75 in the retracted and retracted state shown by the chain double-dashed line in the figure is pulled out forward, for example, manually, the fixing link body 75 is stretched so as to form a triangle as shown by the solid line in the figure. Will be issued. Further, in this projecting state, the first fixing portion 82 for fixing the tension rod, which is provided at the end of the first link portion 75a, projects in front of the boom head 25 as a vertex of a triangle. Therefore, in this state, the tension rod 70 whose one end is fixed to the tip of the jib 60 which is directed obliquely downward with respect to the longitudinal axis direction of the boom 18 as shown by the dashed line in the figure.
The other end of can be fixed to the first fixing portion 82.

The tension rod 70 is removed from the state in which the jib 60 together with the tension rod 70 are projected to the front of the boom 18 in this way, and the boom head 2 is removed.
When 5 is rotated about the rotation shaft 35 as described above and stored in the side of the boom 18 in the upper inclined state (state of FIG. 1), the jib 60 attached to the boom head 25 also moves together with the boom head 25. It rotates and is positioned on the side of the boom 18 in an upper inclined state (see FIGS. 1 and 4). Accordingly, the jib 60 can be easily and smoothly stored on the side of the boom, and the jib 60 can be arranged on the upper side of the boom side surface. When the jib 60 in the storage position on the side of the boom 18 is extended to the tip side of the boom 18, the jib 60 is stored with the boom head 25 on the side of the boom as shown in FIG. Of the engaging portions 62, 62 and the sheave shafts 33a, 33
After engaging with a, the boom head 25 may be rotated together with the jib 60 toward the tip of the boom 18. In this case, by inserting the retaining pin 99 into the engaging portions 62, 62, the sheave shaft 33 of the jib 60 is inserted.
It is prevented from coming off from a and 33a.

As described above, according to this embodiment, the boom head 25 is rotated about the rotation shaft 35 with respect to the boom 18 from the state shown in FIG.
As shown in FIG. 5B, the boom 18 can be stored laterally. Therefore, the total length of the mobile crane is L
(See (a) of FIG. 5) to L ′ (see (b) of FIG. 5), and as a result, the boom head 25 collides with a preceding vehicle or an obstacle when the crane vehicle moves. It is possible to avoid the danger of the occurrence of a traffic accident, or to allow the mobile crane to smoothly pass through a narrow corner.

Further, in the present embodiment, the boom head 25
As described above, since the rotation shaft 35 of the is inclined toward the front of the boom 18, the boom head 25 is moved to the position shown in FIG.
It can be stored on the side of the boom 18 while being tilted upward as shown in FIG. As a result, the boom head 25 can be stored in the lower side of the boom 18 without largely protruding, and as a result, the approach angle can be increased by α.
(See (a) of FIG. 5) to α ′ (see (b) of FIG. 5).

In this way, the boom head 25 is attached to the boom 1
The fact that the boom 18 can be stored in the upper tilted state without being largely projected to the lower side is particularly useful in a crane vehicle that travels with the boom 18 lying above the cab 14 as shown in FIG. That is, in the mobile crane as shown in FIG. 6, when the boom head 25 is moved from the projecting state shown in FIG. 6A to the stored state shown in FIG. 6B,
The visibility from the cab 14 is not obstructed by the boom head 25, and safety during traveling is ensured. For example, as in the conventional example shown in FIG. 7B, the boom head 103
Since the amount of protrusion of the boom head 103 to the lower side of the boom 102 does not change when the boom is rotated about an axis substantially perpendicular to the longitudinal axis direction of the boom 102, depending on the amount of protrusion of the boom head 103, the amount of protrusion from the cab 14 may vary. Sight is boom head 10
May be blocked by 3. On the other hand, in the present embodiment, the boom shaft 25 can be stored in a state of being tilted upward by the tilt shaft 35 to reduce or eliminate the amount of protrusion of the boom head 25 to the lower side of the boom. A good view from can be secured.

Further, in the present embodiment, the boom head 25
Since the jib 60 is attached using the sheave shaft 33a, that is, the jib attachment portion is provided on the boom head 25, the boom head 25 can be simply rotated about the rotation shaft 35. The jib 60 attached to the boom can be rotated together with the boom head 25 to be positioned on the side of the boom 18 in an upper inclined state. Therefore, the jib 60 can be easily and smoothly stored on the side of the boom, and the jib 60 can be stored while being inclined relatively to the side of the boom. Also,
Since the jib 60 can be stored on the side of the boom 18, the jib 6
Compared with the case where 0 is stored in the lower surface of the boom 18, the boom fall position during traveling can be lowered, and as a result, the center of gravity of the boom 18 is lowered, and stability during traveling can be improved. Of course, since the jib 60 is not stored on the lower surface of the boom 18, the visibility from the cab is good.

Further, in the present embodiment, the boom head 25
The hydraulic cylinder 65 for rotating the telescopic boom 18
Since it is arranged in the inner space of the most advanced boom 18b located on the innermost side of the hydraulic cylinder 65, damage to the hydraulic cylinder 65 due to collision with an obstacle can be prevented. Further, since it is not necessary to secure a mounting space for the hydraulic cylinder 65 outside the boom 18, the space can be effectively used and the degree of freedom in design is improved.

Further, in this embodiment, the boom head 2
5, the link body 75 for fixing the tension rod is provided so as to be capable of projecting and retracting. Therefore, there is an inconvenience caused by tilting the rotating shaft 35, that is, depending on the length, the tension rod 70 is moved to the boom head 25. The inconvenience that it cannot be attached can be eliminated. In the case of this embodiment, the link body 75 forms a triangle in the projecting state, which is very advantageous in terms of strength. Further, in the present embodiment, the link body 75 is manually extended, but this may be automatically performed using a hydraulic cylinder or the like.

[0034]

As described above, according to the boom head retracting mechanism of the present invention, the boom head can be retracted to the side of the boom, and at the time of retracting the boom head, the front view from the cab is sufficiently secured. Yes, the approach angle can be made sufficiently large.

[Brief description of drawings]

FIG. 1 is an overall view of a wheel crane including a boom head storage mechanism according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of the boom head storage mechanism according to the embodiment of the present invention.

FIG. 3 is a view taken in the direction of arrow AA in FIG.

FIG. 4 is a plan view of a boom tip portion where a boom head is located.

FIG. 5 is an explanatory diagram for explaining the operation of the boom head retracting mechanism according to the embodiment of the present invention, in which (a) is a boom head retracting mechanism provided on a wheel crane and the boom head is attached to the tip of the boom. FIG. 7B is a diagram showing a state in which the boom head is stored, and FIG. 9B is a diagram showing a state in which the boom head is stored in the side of the boom by the boom head storing mechanism from the state of FIG.

FIG. 6 is an explanatory diagram for explaining the operation of the boom head storage mechanism according to the embodiment of the present invention, in which FIG. 6 (a) is provided in a crane vehicle that travels with the boom lying down above the cab. The figure which shows the state where the boom head was located at the tip of the boom by the boom head storage mechanism, and the figure which shows the state which stored the boom head to the side of the boom by the boom head storage mechanism from the state of (a). is there.

FIG. 7 (a) is a schematic side view of a wheel crane,
(B) shows a state in which the boom head is located at the tip of the boom and a state in which the boom head is stored at the side of the boom by a conventional boom head storage mechanism provided in a crane vehicle traveling with the boom lying down above the cab. FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Wheel crane 18 (18a, 18b) ... Boom 25 ... Boom head 35 ... Rotating shaft 65 ... Hydraulic cylinder (rotating means) 68 ... Link mechanism (rotating means)

Claims (3)

[Claims] 1. A boom head retracting mechanism for a self-propelled crane in which a boom head provided at the tip of a boom is rotated with respect to the boom and retracted to the side of the boom. And a boom axis that tilts the upper end of the boom head toward the tip side of the boom so as to form a predetermined angle with the axis perpendicular to the longitudinal axis of the A boom head retracting mechanism for a self-propelled crane, comprising: a rotating unit that rotates the rotating shaft around the rotating shaft. 2. The self-propelled device according to claim 1, wherein the rotating means comprises a hydraulic cylinder installed on the boom, and a link mechanism connecting the telescopic rod of the hydraulic cylinder and the boom head. Boom crane retractor for mobile cranes. 3. A boom head is provided with a mounting portion for mounting a jib that supplements the length of the boom, and a boom head has a fixing means for fixing the other end of a tension rod whose one end is connected to the tip of the jib. The boom head retracting mechanism for the self-propelled crane according to claim 1, wherein the boom head retracting mechanism is provided so as to be capable of projecting and retracting freely.