JP7172489B2 - Boom support base - Google Patents

Description

The present invention relates to a boom support base. More particularly, it relates to a boom support base that supports a boom and a hoisting cylinder for hoisting the boom.

As for a boom support base for construction machinery, there is a prior art disclosed in Patent Document 1.
This prior art, as shown in FIG. 6, has an upper swivel base 102 mounted on the traveling device of the aerial work vehicle. 107 are mounted at intervals. Mounting frames 113, 113 for the pair of luffing cylinders 105 are mounted spaced between the boom mounting frames 107, 107. As shown in FIG. Cylindrical bosses 117 , 117 are attached to the inside of the mounting frames 113 , 113 . The mounting frames 113, 113 are triangular plates that are triangular in side view. The hoisting cylinder 105 is supported by a pin 118 passed through a pair of mounting frames 103 and 103 and a pair of bosses 117 and 117 . The bases of the triangles of the mounting frames 113, 113 are fixed to the upper surface of the swivel base 102 by welding or the like.

In the prior art described above, when the hoisting cylinder 105 is extended while the boom is in a nearly horizontal state, a force that pushes the mounting frame 113 backward acts. An external force is applied in the direction that the part is torn off from the swivel base 2 . The mounting frame 113 is likely to be damaged by this large external force.
Since the mounting frames 113, 113 are each a single plate, they have less area to support the load applied by the luffing cylinder 105. FIG. Therefore, the cylindrical bosses 117, 117 are attached. Although this makes it possible to increase the support area for the pin 118 that supports the base end portion 116 of the hoisting cylinder 105, the route from the pin 118 to the swivel base 102 is limited. The support area cannot be increased.

Therefore, a boom support base 200 as shown in FIG. 5 has been developed.
The boom support base 200 also serves as a swivel base of the mobile crane, and is a member that supports the boom and the hoisting cylinder. The illustrated boom support base 200 has a bottom plate 201 and a pair of side plates 202, 202 (only the back side is illustrated and the front side is omitted). A pin support structure 210 is mounted on the bottom plate 201 . The pin support structure 210 consists of a pair of cylindrical bosses 211 and a support base 212 supporting the cylindrical bosses 211 . The support base 212 is fixed to the upper surface of the bottom plate 201, and the two cylindrical bosses 211 are extended to abut on the left and right side plates 202, 202 while leaving a mounting space for the base of the hoisting cylinder.

As described above, an attempt has been made to make the cylindrical boss 211 longer and reach the side plates 202, 202 so that the pin support structure 210 supports the load applied from the hoisting cylinder.
However, according to this structure, not only the cylindrical boss 211 becomes long, but also the support pin to be passed through the boss 211 becomes long, which causes problems such as a considerable increase in weight and an increase in the number of parts.

JP-A-2000-255999

SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to provide a boom support base that can disperse the load applied from the hoisting cylinder, reduce the weight of the pin support structure, and reduce the number of parts.

A boom support base according to a first aspect of the invention is a boom support base that supports a boom and a hoisting cylinder for hoisting the boom, wherein a pin support structure for supporting a base end of the hoisting cylinder comprises a boom supporting base. It is provided on a base, and the pin support structure consists of a mounting frame made of a thick plate and a bottom receiving plate that supports the mounting frame from below , and the mounting frame comprises a main frame member and a reinforcing frame member. The reinforcing frame member has a lower edge that protrudes downward from the lower surface of the bottom receiving plate, and the bottom receiving plate extends from the lower edge of the reinforcing frame member. It is characterized by being welded to the side surface of the part .
A boom support base according to a second aspect of the invention is characterized in that, in the boom support base of the first aspect, the bottom support plate comprises a horizontal horizontal support plate portion and an inclined tilt support plate portion.
A boom support base according to a third aspect of the invention is characterized in that, in the second aspect of the invention, the inclined receiving plate portion comprises a first inclined portion with a shallow inclination angle and a second inclined portion with a deep inclination angle.

According to the 1st invention, there exist the following effects.
a) When the load applied by the luffing cylinder is transmitted to the boom support base, the load is transmitted to the bottom plate through the mounting frame, so that the load can be received by a large area of the bottom plate. Effective load distribution. In addition, since the pin support structure can be constructed only by the plate material consisting of the mounting frame and the bottom receiving plate, the weight can be reduced. Furthermore , since no cylindrical boss is used as in the prior art, the number of parts can be reduced.
b) Since the mounting frame has a double thick plate structure in which the main frame member and the reinforcing frame member are superimposed, the contact area with the support pin of the hoisting cylinder increases, reducing the surface pressure and damaging the mounting frame. can support the load without
c) Since the lower edge of the reinforcing frame member abuts the end surface of the bottom receiving plate, the bottom receiving plate can be welded firmly, and the mounting frame including the reinforcing frame member can be supported so as not to fall down, thereby preventing damage to the mounting frame. more effective.
According to the second invention, when the hoisting cylinder is upright, the load is mainly received by the horizontal receiving plate portion, and when the hoisting cylinder is laid down, the rearward load can be received mainly by the inclined receiving plate portion. It has a high load bearing capacity because it is received at an angle close to a right angle.
According to the third aspect of the invention, while the hoisting angle of the hoisting cylinder changes, the ratio of the load sharing between the first sloping portion with a shallow angle and the second slanting portion with a deep angle changes. High load bearing capacity can be maintained even at an angle.

It is a perspective view of boom support base 1 concerning one embodiment of the present invention. 4 is a plan view of the pin support structure 10; FIG. 4 is a front view of the pin support structure 10; FIG. 2 is a side view of pin support structure 10. FIG. 1 is a perspective view of a conventional boom support base; FIG. FIG. 10 is a side view (A view) and a plan view (B view) showing the boom support base described in Patent Document 1;

Next, embodiments of the present invention will be described with reference to the drawings.
The boom support base of the present invention includes those mounted on a moving body such as a vehicle body and a hull as well as those mounted on a fixed base. It also includes those in which the boom support base itself rotates and those in which it does not rotate.
In the following embodiments, an example in which a boom support base is applied to a swivel base having a swivel function in construction machines such as crane trucks and aerial work vehicles will be described.

A boom support base 1 in FIG. 1 comprises a bottom plate 2 and a pair of side plates 3, 3 (only the back side is shown and the front side is omitted). The front part (the left part in the figure) of the boom support base 1 is a swivel unit fixing part 1A fixed to the swivel bearing unit on the traveling vehicle body, and the rear part (the right part in the figure) is the boom ( (illustration omitted) is a boom fixing portion 1C that supports the base portion of the boom with a pin. An intermediate portion of the boom support base 1 is a hoisting cylinder attachment portion 1B to which a pin support structure 10 for supporting the hoisting cylinder is attached.

A bottom plate 2 of the fixed portion 1A is made of a horizontal plate material. Here, the term "horizontal" refers to horizontal when a vehicle is normally used on a horizontal and flat road.
The bottom plate 2 of the boom mounting portion 1C is inclined so as to rise toward the rear end. The side plates 3, 3 of the boom mounting portion 1C are formed with pin holes 4, 4 for inserting pins for mounting a boom (not shown).

Next, the pin support structure 10 will be described with reference to FIGS. 1 to 4. FIG.
The pin support structure 10 consists of a mounting frame 20 and a bottom plate 30 .
The mounting frame 20 includes a main frame member 21 and a reinforcing frame member 22 which are integrally fixed by welding or the like with their side surfaces overlapping each other. With such a two-ply structure, the mounting frame 20 has a double thick plate structure made of metal.

The main frame member 21 is composed of a substantially rectangular main body portion 21a and leg portions 21b extending forward from the main body portion 21a. The reinforcing frame member 22 has a substantially quadrilateral shape with a triangular portion protruding forward and downward at the front lower end.
The body portion 21a and the reinforcing frame member 22 configured as described above are formed with pin holes 23 through which support pins for supporting the base portion of the hoisting cylinder are inserted. 3 shows a state in which the support pin 6 is passed through the pin hole 23. As shown in FIG.

The bottom receiving plate 30 is composed of a horizontal receiving plate portion 31 and an inclined receiving plate portion 32 . The horizontal receiving plate portion 31 is a substantially horizontal receiving plate portion, and the inclined receiving plate portion 32 is inclined downward in the front direction.
The inclined receiving plate portion 32 is composed of a first inclined portion 33 and a second inclined portion 34 . The rear end of the first inclined portion 33 continues to the front end of the horizontal receiving plate portion 31 , and the rear end of the second inclined portion 34 continues to the front end of the first inclined portion 33 . The inclination of the inclined receiving plate portion 32 is such that the front is downward, the inclination angle of the first inclined portion 33 is shallow, and the inclination angle of the second inclined portion 34 is deep. With such a structure, the bottom receiving plate 30 has an arch shape that is convex upward.

When viewed from the front, the bottom receiving plate 30 is divided into three parts as shown in FIG. The first part 30A is between the pair of mounting frames 20,20. The second part 30B is between one mounting frame 20 and one side plate 3, and the third part 30C is between the other mounting frame 20 and the other side plate 3. As shown in FIG.
The bottom receiving plates 30 of the first to third parts are all welded to the pair of mounting frames 20 and 20 and also welded to the pair of side plates 3 and 3 of the boom support base 1 .

The bottom receiving plate 30 of the first part 30A and the bottom receiving plate 30 of the third part 30C are welded to the reinforcing frame member 22 outside the main frame member 21. As shown in FIG.
More specifically, the lower edge of the reinforcing frame member 22 penetrates below the lower surface of the bottom receiving plate 30, and the end surface of the bottom receiving plate 30 is abutted against the side surface of the lower edge and welded. ing.
In FIGS. 2 and 3, the welded portion of the horizontal receiving plate portion 31 and the inclined receiving plate portion 32 shows the groove before welding, and does not show the build-up after welding.

In the first part 30</b>A of the bottom receiving plate 30 , a reinforcing plate 36 is welded to the upper surface of the portion from the upper surface of the horizontal receiving plate portion 31 to the first inclined portion 33 .
The reinforcing plate 36 is also fixed by welding to the mounting frame 20 (directly to the main frame member 21).
Since the reinforcing plate 36 is attached to the upper surface of the bottom receiving plate 30 in this manner, the strength of the bottom receiving plate 30 is also increased.

The bottom receiving plate 30 is a member that also serves as the bottom plate of the boom support base 1 . Therefore, the front edge of the bottom plate portion 30 is welded in a state of being connected to the bottom plate 2 of the rotating unit fixing portion 1A. Further, the rear edge of the bottom plate portion 30 is welded so as to be connected to the bottom plate 2 of the boom fixing portion 1C. The bottom receiving plate 30 has an arch-shaped plate structure when viewed from the side by having the inclined receiving plate portion 32 that protrudes upward as described above. Therefore, the structure has a large resistance to loads from above or obliquely above.

The lower edge of the reinforcing frame member 22 constituting the mounting frame 20 penetrates the lower surface of the bottom receiving plate 30 and extends slightly downward as described above. The mounting frames 20, 20 are both sandwiched between the bottom receiving plate 30 and the reinforcing plate 36 from both left and right sides. For this reason, the mounting frames 20, 20 are structured such that they are less likely to fall in either the left or right direction, and can easily be maintained in an upright state.

The rear end portion of the main frame portion 21a of the main frame member 21 constituting the mounting frame 20 is cut obliquely, and is welded in contact with the bottom plate 2 of the boom mounting portion 1B.
The tip bottom of the leg 21 of the main frame member 21 is welded while being inserted into the upper surface of the box-shaped base 25 . This box-shaped base 25 is a member configured as a thick plate in the rotating unit fixing portion 1A.

Based on FIG. 4, the function of the pin support structure 1 according to this embodiment will be described. 4 shows only the base end portion of the hoisting cylinder 5. As shown in FIG.
When the hoisting cylinder 5 is extended, the boom (not shown) can be raised from a nearly horizontal state to a nearly vertical standing state, and the hoisting cylinder 5 itself is similarly raised.
When the hoisting cylinder 5 is contracted, the boom can be lowered from the upright state to the laid down state, and the hoisting cylinder 5 also performs the similar motion.
In the figure, the symbol V indicates the erected state of the hoisting cylinder 5, and the symbol H indicates the collapsed state of the hoisting cylinder 5. As shown in FIG.

As shown in FIG. 4, when the hoisting cylinder 5 is upright (in the V direction), a downward load W1 acts. The load W1 is received by the bottom receiving plate 30 as a whole, and since the bottom receiving plate 30 has an arch shape that is convex upward, it has high durability against the external force from above. Therefore, the load from the luffing cylinder 5 can be supported without damaging the pin support structure 1 .

When the hoisting cylinder 5 is in a horizontal state (H direction), a rearward and horizontal load W2 acts. The load W2 is mainly received by the first inclined portion 33 and the second inclined portion 34 of the bottom receiving plate 30. Since the inclined receiving plate portion 32 receives the load W2 while facing the load W2, the endurance is increased. high and not easily damaged.

Since the lower edge of the reinforcing frame member 22 is below the lower surface of the bottom receiving plate 30 , the end surfaces of the horizontal receiving plate portion 31 and the inclined receiving plate portion 32 are welded to the side surfaces of the reinforcing frame member 22 . This doubles the welding area compared to the case where the lower end surface of the reinforcing frame member 22 is welded to the upper surface of the bottom receiving plate 30 . Therefore, even if the lateral load W2 from the hoisting cylinder 5 is received, damage such as the mounting frame 20 being peeled off from the upper surface of the bottom receiving plate 30 is unlikely to occur.

The boom support base 1 of this embodiment has the following advantages.
(1) Since the mounting frame 20 has a double thick plate structure in which the main frame member 21 and the reinforcing frame member 22 are superimposed, the contact area with the support pin of the hoisting cylinder 5 is increased and the surface pressure is reduced. The load can be supported without damaging the mounting frame 20. - 特許庁
(2) Since the lower edge of the reinforcing frame member 22 abuts the end surface of the bottom receiving plate 30, the bottom receiving plate 30 can be welded firmly and the mounting frame including the reinforcing frame member can be supported so as not to fall down. The effect of preventing damage to the mounting frame is enhanced.
(3) When the hoisting cylinder 5 stands upright, the load is mainly received by the horizontal receiving plate portion 31, and when the hoisting cylinder 5 is laid down, the rearward load can be received mainly by the inclined receiving plate portion 32. It has a high load bearing capacity because it is received at an angle close to a right angle.
(4) While the hoisting angle of the hoisting cylinder 5 is changing, the ratio of load sharing between the first sloping portion 33 with a shallow angle and the second sloping portion 34 with a deep angle changes. High load bearing capacity can be maintained even at an angle.

Including the effects (1) to (4) above, the boom support base 1 of the present invention has the following effects.
When transmitting the load applied by the hoisting cylinder 5 to the boom support base 1, the load is transmitted to the bottom receiving plate 30 via the mounting frame 20, so that the load can be received by a wide area of the bottom receiving plate 30. , load balancing can be performed effectively. Further, since the pin support structure 10 can be made of a plate material including the mounting frame 20 and the bottom receiving plate 30, the weight can be reduced.
Moreover, since there is no need to use a cylindrical boss or a long support pin as in the prior art, the weight reduction effect is great and the number of parts can be reduced.

Reference Signs List 1 boom support base 2 bottom plate 3 side plate 4 pin hole 5 hoisting cylinder 10 pin support structure 20 mounting frame 21 main frame material 22 reinforcing frame material 23 pin hole 30 bottom receiving plate 31 horizontal receiving plate portion 32 inclined receiving plate portion 33 first Inclined portion 34 Second inclined portion 36 Reinforcing plate

Claims (3)

A boom support base that supports a boom and a hoisting cylinder for hoisting the boom,
A pin support structure for pin-supporting the base end of the hoisting cylinder is provided on the boom support base,
The pin support structure comprises a mounting frame made of a thick plate and a bottom receiving plate that supports the mounting frame from below ,
The mounting frame is composed of a main frame member and a reinforcing frame member, which are fixed with their side surfaces overlapping each other,
The reinforcing frame member has a lower edge that protrudes downward from the lower surface of the bottom receiving plate, and the bottom receiving plate is welded to the side surface of the lower edge of the reinforcing frame member.
A boom support base, characterized by : 2. The boom support base according to claim 1 , wherein said bottom support plate comprises a horizontal horizontal support plate portion and an inclined tilt support plate portion. 3. The boom support base according to claim 2 , wherein the inclined receiving plate portion comprises a first inclined portion with a shallow angle of inclination and a second inclined portion with a large angle of inclination.

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