JP3612882B2 - Shovel loader lift arm stopper mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a stopper mechanism for a lift arm in an excavator loader, and more particularly, to a stopper mechanism for locking a lift arm pivotally attached to a main body portion of the shovel loader at a raised position.
[0002]
[Prior art]
As a conventional shovel loader, as shown in FIG. 8, a reach arm 32 is pivotally mounted on the lower front side of the vehicle main body 31, and a tip of the reach arm 32 is formed in a bifurcated portion, between the bifurcated portions 32a and 32a. The lift arm 33 is pivotally mounted, and the positions slightly above the lower end of the reach arm 32 and slightly distal from the base end of the lift arm 33 are pivotally attached to the reach cylinder (not shown) and the lift cylinder 34, respectively. It is known that the lift arm 33 moves up and down as the cylinders expand and contract. Further, the conventional shovel loader has a cylindrical holder 35 attached to the approximate center of the reach arm 32 as a stopper mechanism of the lift arm 33, and a cylindrical stopper pin 36 is housed inside the holder 35. It has a structure in which two insertion holes 32b and 32b are formed in the bifurcated portions 32a and 32a at the tip of the reach arm 32. When the lift arm 33 is kept lifted at the time of inspection and maintenance, as shown in FIG. 9, the stopper pin 36 is lifted by using the insertion holes 32b and 32b of the bifurcated portions 32a and 32a. The lift arm 33 is suspended so that the lift arm 33 is not lowered even if an oil leak or the like occurs in the hydraulic circuit of the reach cylinder or the lift cylinder 34.
[0003]
[Problems to be solved by the invention]
However, in the conventional lift arm stopper mechanism, when the lift arm 33 is locked in the raised position, the stopper pin 36 is removed from the holder 35 and inserted into the through holes 32b and 32b of the bifurcated portions 32a and 32a. The work was very troublesome. Further, the stopper pin 36 may be dropped and damaged during the locking operation. Furthermore, since the stopper pin 36 is provided separately from the vehicle body 31 of the shovel loader, it may be lost when it is pulled out from the insertion holes 32b, 32b of the bifurcated portions 32a, 32a and is lost. .
[0004]
An object of the present invention is to solve the problems of the conventional lift arm stopper mechanism and to provide a highly functional stopper mechanism that can lock the lift arm in the raised position very easily without any inconvenience. Is to provide.
[0005]
[Means for Solving the Problems]
Among the present inventions, the configuration of the first invention is a stopper mechanism for locking the lift arm of the shovel loader in the raised position, and the base end is pivotally attached to the main body of the shovel loader and the tip is bifurcated. And a reach arm having a contact portion below the bifurcated portion and having a proximal end of the lift arm pivoted between the bifurcated portions, and a bifurcated portion of the lift arm base. A shaft member penetrating the pivot arm at the lower end of the pivot arm so as to cross the pivot range of the lift arm, and an inner and outer portion of the pivot range of the lift arm along the axial direction of the shaft member. And a fixed member that is positioned below the lift arm that is in the raised position and prevents the lift arm from rotating downward when moved within the pivot range of the lift arm. The fixing member is polygonal When the lift arm is lowered after being moved into the rotation range of the lift arm along the axial direction of the shaft member, the shaft member penetrates perpendicularly to the bottom surface of the polygonal column. The upper and lower side surfaces are sandwiched between the lower surface of the lift arm and the contact portion in a state where the lift arm and the contact portion are in contact with each other, and the downward rotation of the lift arm in the raised position is prevented. It is in.
[0008]
According to a second aspect of the present invention, in the first aspect , the shaft member has a thread groove on an outer periphery and is pivotally attached to the bifurcated portion, and the fixing member is a thread groove. The fixing member is externally fitted to the shaft member in a state in which the screw groove on the outer periphery of the shaft member is screwed into the screw groove of the insertion hole. It is to move with rotation.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a stopper mechanism for a lift arm of the present invention will be described in detail with reference to the drawings.
[0010]
FIG. 1 shows an excavator loader provided with a stopper mechanism for a lift arm (FIG. 1 shows a state where the lift arm is raised). Two reach arms 2, 2 are pivotally attached to the lower front side of the vehicle body 1, and are arranged parallel to the vehicle width direction from the lower end of the vehicle body 1 upward. . Each reach arm 2 is pivotally attached to the tip of a reach cylinder (not shown) at a position slightly on the tip side from the base end, and a flat contact portion 2a is formed at the tip. The connecting pieces 2b and 2b are joined to the left and right of the portion 2a to form a bifurcated shape. A cargo handling pin 3 is penetrated at the upper ends of the connecting pieces 2b, 2b, which are the forked portions, and the base end of the lift arm 4 and the intermediate portion of the bell crank 5 are pivotally attached between the connecting pieces 2b, 2b. It is in the state that was done. Further, mainly on the pivot arm of the lift arm 4 at the tip of the reach arm 2, the connecting pieces 2b and 2b, the shaft member 11 penetrating the connecting pieces 2b and 2b, and the shaft member 11 are externally fitted. A stopper mechanism including a stopper piece 21 as a fixed member is provided. The lift arm 4 is pivotally attached to the tip of the lift cylinder 6 at a position slightly distal to the base end, and a bucket 7 is pivotally attached to the tip. Further, in the bell crank 5, a reach arm rod 8 is pivotally attached to a rear portion of the lower end, and a lift arm rod 9 is pivotally attached to an upper end portion.
[0011]
On the other hand, FIG. 2 is an enlarged view of the peripheral portion of the connecting piece 2b, 2b at the tip of the reach arm 2. FIG. 3 shows the peripheral portion of the connecting piece 2b, 2b in the axial direction of the cargo handling pin 3. It shows the state of being cut. In this embodiment, the base end of the lift arm 4 is pivotally attached to the innermost position (right side in FIG. 5) in the vehicle width direction between the connecting pieces 2b and 2b. The middle part is pivotally attached. A spacer 10 is loosely fitted outside the intermediate portion of the bell crank 5.
[0012]
Moreover, the shaft member 11 is penetrated below the penetration part of the cargo handling pin 3 of the connection pieces 2b and 2b. FIG. 4 shows the shaft member 11, and the shaft member 11 has a tip formed with a smaller diameter than the main body portion 12, and a screw groove 14 is screwed on the outer periphery on the front side of the small diameter portion 13. . A knob 15 is provided at the base end, and a thread groove 16 is threaded on the outer periphery of the main body 12 except for a portion adjacent to the knob 15. As shown in FIG. 3, the shaft member 11 slides the smooth portion 17a of the small diameter portion 13 and the smooth portion 17b adjacent to the knob 16 onto the wall surfaces of the pivot holes 18 and 18 formed in the connecting pieces 2b and 2b. In a state of being in contact with each other, it is suspended so as to pass through the connecting pieces 2b, 2b, and the thread groove 14 at the tip is screwed to the nut 20 via the washer 19, so that it can rotate freely. .
[0013]
Furthermore, a stopper piece 21 as a fixing member is fitted on the shaft member 11. In this embodiment, the stopper piece 21 is formed in a triangular prism shape in a polygonal column, and an insertion hole is formed perpendicularly to the bottom surface of the triangular column, and the screw hole of the shaft member 11 is formed in the insertion hole. A thread groove having the same pitch as 16 is threaded. Then, the screw groove of the insertion hole is screwed into the screw groove 16 of the shaft member 11 and the lower surface is fitted to the outer side of the shaft member 11 with the lower surface in contact with the contact portion 2a at the tip of the reach arm 2. Has been.
[0014]
The function of the lift arm stopper mechanism in the shovel loader configured as described above will be described below. In a normal state, as shown in FIG. 5A, the stopper piece 21 is disposed outside the rotation range of the lift arm 4 that is the release position (that is, the position where the lift arm 4 does not contact even if the lift arm 4 rotates). . When locking the lift arm 4 in the raised position, first, the reach cylinder is contracted by operating an operation switch (not shown) installed on the front panel (not shown) of the driver seat of the excavator loader. In this state, the lift cylinder 6 is extended to raise the lift arm 4. And after raising the lift arm 4 to a predetermined position, the shaft member 11 is rotated using the knob 15. When the shaft member 11 is rotated, the stopper piece 21 slides on the contact portion 2a with the rotation of the stopper piece 21, and the lift arm 4 that is the lock position is rotated along the axial direction of the shaft member 11. It moves to within the movement range (that is, the lower position of the lift arm 4) (see FIG. 5B). Thereafter, the lift arm 4 is slowly lowered, and the lower surface of the lift arm 4 is brought into contact with the upper surface of the stopper piece 21.
[0015]
The excavator loader is configured so that the hydraulic circuit of the reach cylinder and the lift cylinder 6 is cut off and the lift arm 4 is not lowered unless the operation switch is operated with the lift arm 4 raised. As described above, if the stopper piece 21 is moved to the rotation range of the lift arm 4, even if a situation such as oil leakage occurs in the hydraulic circuit, the stopper piece 21 is Is held between the lower surface of the lift arm 4 and the contact portion 2a of the reach arm 2 so as to ensure that the lift arm 4 is pivoted downward. To stop.
[0016]
When it is desired to freely rotate the lift arm 4 again, the shaft member 11 is rotated in the opposite direction using the knob 15. When the shaft member 11 is rotated in the opposite direction, the stopper piece 21 slides the lower surface on the contact portion 2a along with the rotation, and the lift arm 4 moves along the axial direction of the shaft member 11. Since it moves out of the rotation range, the lift arm 4 is in a freely rotatable state (see FIG. 5A).
[0017]
Since the lift arm stopper mechanism of the embodiment is configured as described above, if the stopper piece 21 is moved within the rotation range of the lift arm 4, there should be a situation such as oil leakage in the hydraulic circuit. Even if it occurs, the lift arm 4 can be reliably locked in the raised position. Further, since the stopper piece 21 is integrally incorporated in the vehicle body 1, the stopper pin may be dropped during the locking operation or the removed stopper pin may be lost as in the conventional stopper mechanism. There is no. Furthermore, since the stopper piece 21 can be easily moved to the rotation range of the lift arm 4 simply by rotating the shaft member 11 using the knob 15, the locking operation is very easy. On the other hand, the stopper piece 21 is formed in a triangular prism shape, penetrates the shaft member 11 perpendicularly to the bottom surface of the triangular prism, and the upper and lower side surfaces are in contact with the lower surface of the lift arm 4 and the contact portion 2a. In this state, the lift arm 4 is sandwiched between the lower surface of the lift arm 4 and the contact portion 2a to prevent the lift arm 4 in the raised position from rotating downward, so that the load of the lift arm 4 is received in a large area. Therefore, the lift arm having a larger load can be reliably locked.
[0018]
The configuration of the lift arm stopper mechanism of the present invention and the configuration of the shovel loader on which the stopper mechanism is mounted are not limited to the above-described embodiments, and the shape of the reach arm, shaft member, stopper piece The structure, the structure of the connection structure of each arm in the shovel loader, and the like can be changed as appropriate.
[0019]
For example, the shaft member does not have a structure with a knob, but can have a structure in which a handle 22 is integrally attached to one end of the shaft member 11 'as shown in FIG. When such a configuration is adopted, there is an advantage that the stopper piece 21 can be easily moved by rotating the handle 22. Moreover, it can also be set as the structure which attaches a motor etc. to a shaft member and moves a stopper piece by forward / reverse rotation of a motor. On the other hand, as shown in FIG. 7, the shaft member 11 ″ is joined to the connecting pieces 2b and 2b without screwing the inside of the insertion hole of the main body portion 12 ″ and the stopper piece 21 ″ of the shaft member 11 ″, and the stopper piece 21 ″. It is also possible to make it a structure which moves by sliding along the outer periphery of the main-body part 12 '' of the shaft member 11 ''. When such a structure is adopted, the manufacturing cost becomes low. There is a merit.
[0020]
In addition, in the above embodiment, the stopper mechanism provided at the base end of the lift arm on one side has been described. However, the stopper mechanism can also be provided at the base ends of the lift arms on the left and right sides of the vehicle body. The shovel loader referred to in the present invention is not limited to a work vehicle in which a bucket is pivotally attached to the tip of a lift arm, and various operations can be performed by rotating a reach arm, a lift arm, and the like. Such a general working vehicle is included, and the stopper mechanism of the present invention can be widely applied to other working vehicles other than the shovel loader.
[0021]
The fixing member (stopper piece) is not limited to a polygonal prism including a triangular prism, and has any other shape that has a portion that abuts against the lower surface of the lift arm and the abutting portion and that can be displaced along the shaft member. May be. For example, the shape etc. which provided the latching member which prevents a rotation at the time of the movement along an axis | shaft and the axis | shaft to a sphere etc. are mentioned. Further, the part where the fixing member contacts the lift arm and the reach arm may be any part. The shape need not be flat.
[0022]
Further, the reach arm is not limited to the one having a bifurcated tip. For example, the reach arm may have a shape in which the two plate members are fixed so as to have a constant interval. Alternatively, a single rod-shaped member may be used, and the tip of the lift arm may be supported by a cantilever structure. However, in this case, the shaft member also has a cantilever structure.
[0023]
【The invention's effect】
According to the stopper mechanism of the first invention, when the fixing member is moved within the rotation range of the lift arm, the lift arm should be in the raised position even if an oil leak occurs in the hydraulic circuit. Ru can be locked securely. Further, since the fixing member is integrally incorporated in the vehicle main body with a very rational structure, it is possible to prevent a situation where the fixing member is dropped or lost during the locking operation, and the manufacturing is facilitated. Further, the polygonal columnar fixing member is sandwiched between the lower surface of the lift arm and the contact portion with the upper and lower side surfaces in contact with the lower surface of the lift arm and the contact portion, and below the lift arm in the raised position. Since the lift arm receives the load of the lift arm in a larger area than the stopper pin of the conventional stopper mechanism, the reliability of the lock function of the lift arm is further enhanced.
[0026]
According to the stopper mechanism of the second aspect of the invention, the fixing member can be easily moved simply by rotating the shaft member, so that the lift arm can be locked / released very easily.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a shovel loader.
FIG. 2 is an explanatory view showing an enlarged peripheral portion of a connecting piece.
FIG. 3 is an explanatory view showing a state in which a peripheral portion of a connecting piece is cut in the axial direction of a cargo handling pin.
FIG. 4 is an explanatory view showing a shaft member.
FIG. 5 is an explanatory diagram showing functions of a stopper mechanism.
FIG. 6 is an explanatory view showing a modified example of the stopper mechanism.
FIG. 7 is an explanatory view showing a modified example of the stopper mechanism.
FIG. 8 is an explanatory view showing a conventional shovel loader.
FIG. 9 is an explanatory view showing a mounting state of a stopper pin in a conventional shovel loader.
[Explanation of symbols]
1 .... vehicle body, 2 .... reach arm, 2a ... contact part, 2b ... connecting piece, 3 .... loading pin, 4 .... lift arm, 5 .... bell crank, 6 .... lift cylinder, 7 · · Bucket, 8 · · Reach arm rod, 9 · · Lift arm rod, 10 · · Spacer, 11, 11 ', 11 "· · Shaft member, 12, 12" · · Body portion, 13 · · Small diameter portion, 14 .. Thread groove, 15 .. Knob, 16 .. Thread groove, 17 a, 17 b.. Smooth portion, 18 .. Pivoting hole, 19 .. Washer, 20 .. Nut, 21, 21 ". , 22 .. Handle, 31 .. Vehicle body, 32 .. Reach arm, 32 a .. Bifurcated portion, 32 b .. Insertion hole, 33 .. Lift arm, 34 .. Lift cylinder, 35. Stopper pin.

Claims (2)

A stopper mechanism for locking the lift arm of the shovel loader in the raised position,
The base end is pivotally attached to the main body portion of the shovel loader and the tip is formed in a bifurcated portion, and has a contact portion below the bifurcated portion, and the proximal end of the lift arm is between the bifurcated portions. The reach arm that is pivotally mounted, the shaft member that is the bifurcated portion, below the pivotally mounted portion of the lift arm base end, and that penetrates the rotation range of the lift arm, and the shaft member, It is fitted to the inside and outside of the rotation range of the lift arm so as to be movable along the axial direction of the shaft member, and is positioned below the lift arm when it is moved into the rotation range of the lift arm. And a fixing member that prevents the lift arm from turning downward,
The fixed member is formed in a polygonal column shape, and the shaft member is vertically passed through the bottom surface of the polygonal column, and then lifted along the axial direction of the shaft member within the rotation range of the lift arm. When the arm is lowered, it is sandwiched between the lower surface of the lift arm and the abutting portion with the upper and lower side surfaces abutted on the lift arm and the abutting portion, and moves downward to the lift arm in the raised position. A stopper mechanism for a lift arm of an excavator loader characterized in that it prevents rotation . The shaft member has a screw groove on the outer periphery, and is pivotally attached to the bifurcated portion, and the fixing member has an insertion hole provided with a screw groove,
The fixing member is externally fitted to the shaft member in a state in which the screw groove on the outer periphery of the shaft member is screwed into the screw groove of the insertion hole, and moves as the shaft member rotates. The stopper mechanism of the lift arm of the excavator loader according to Item 1 .

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