JP4808604B2 - Arm telescopic structure of work equipment - Google Patents

Description

  The present invention relates to an arm telescopic structure in various working machines such as a building demolition machine, a construction work machine, and a work machine such as agriculture.

  Conventionally, in the above various working machines, an arm is provided via a boom on a pivotable working machine body that is moved by a crawler, the boom and the arm are raised and lowered by a hydraulic cylinder, and a work such as a bucket is performed at the end of the arm. It is known that the attachment is connected.

As such a working machine, for example, a working machine that collects fruits at a high place (see Patent Document 1), a construction machine that includes a bucket for excavation, and the like are known (see Patent Document 2).
JP 2006-061162 A JP 2004-211505 A

  However, as shown in FIG. 5 (A), the conventional telescopic structure of the arm of the work machine is such that the arms 15 and 16 formed in a box-shaped cylinder are expanded and contracted by a hydraulic cylinder or the like. As shown in FIG. 5, most of the arms 17 and 18 are expanded and contracted by a hydraulic cylinder. In such an arm expansion / contraction structure, since it is a sliding structure, it is necessary to form the arm sliding portion smoothly without backlash for smooth expansion and contraction, and to apply a lubricant. Is also required. Therefore, the manufacturing cost is increased because the slide arm is manufactured with high accuracy for manufacturing the telescopic arm. Therefore, the arm telescopic structure of the working machine according to the present invention has been proposed in order to solve such a problem.

  The gist for solving the above-described problems of the arm telescopic structure of the work machine according to the present invention is to provide an extendable mechanism for extending and retracting an arm provided on the tip side of a boom that can be freely raised and lowered in the work machine. However, the base is rotatably connected to the tip of the boom, and the first arm connected to the boom telescopic device is connected to the upper side of the first arm by a parallel link, and can be swung back and forth. And a second arm that is placed on the upper end surface of the first arm when the first arm is extended in the front-rear direction, and the second arm extends and contracts at the lower part of the arm body. In some cases, there are at least two connecting portions that are detachably connected to a mounting portion provided at the distal end portion of the first arm, and at the rear portion of the arm body of the second arm, It is that the hook to be engaged with the positioning pins for the time expansion which is provided spaced at least two positions before and after in the direction of the first arm is provided at the time of contraction.

  In order to oscillate the second arm, a hydraulically driven drive device installed parallel to the parallel link is provided.

  According to the arm telescopic structure of the working machine of the present invention, for example, the first arm and the second arm and the like are divided into a plurality of arms, and the sliding portion is eliminated without causing the arms to slide. This is what we realized. In addition, the length of the arm changes only when it is extended by the parallel link and when it is contracted, and the length does not change steplessly in the middle of the arm. The manufacturing cost is reduced, the assembly period and cost of the working machine are reduced, and the cost of the entire working machine is reduced.

  As shown in FIG. 1, the arm telescopic structure of the working machine according to the present invention is an arm telescopic structure in various working machines such as a building demolition machine, a construction work machine, and a work machine such as agriculture. This work machine 1 is equipped with a work machine main body 2 provided with a crawler 2 a and having an operation chamber 2 b, a boom 3 provided on the work machine main body 2, which can be raised and lowered, and a front end side of the boom 3. And an attachment 5 such as a working bucket that is detachably connected to the tip of the arm 4 by pin coupling or the like.

  Further, as a drive device for raising and lowering the boom 3 and the arm 4, a boom hydraulic cylinder 6, an arm hydraulic cylinder 7, and an attachment 5 hydraulic cylinder 8 are provided.

  The arm 4 is composed of a plurality of arms, a first arm 4a and a second arm 4b placed thereon. The first arm 4a is rotated by pin coupling, with a connecting hole provided in a base portion 4c interposed in a connecting portion 3a in which a hole for a pin is provided at the tip of the boom 3, and a connecting pin inserted therein. The rod tip 7a of the hydraulic cylinder 7, which is an expansion / contraction device for the boom 3, is pin-coupled and rotatably connected.

  The second arm 4b is pin-coupled by parallel links 9a and 9b on the upper side of the first arm 4a and is swingable in the front-rear direction. Further, when the first arm 4a is expanded and contracted by the parallel links 9a and 9b in the front-rear direction, the first arm 4a is placed in contact with the upper end surface of the first arm 4a.

  As shown in FIGS. 1 to 3, the second arm 4b is attached to and detached from the lower portion of the arm body by a pin connection to a connecting portion 4d which is a mounting portion provided at the distal end portion of the first arm 4a. Connecting portions 4e and 4f that are freely connected are formed at two locations. The connecting portions on the second arm 4b side are provided at two or more places in order to stabilize the strength. In this case, a connecting portion is also provided on the first arm 4a side at a position corresponding to the connecting portion.

  Further, as shown in FIG. 3, the positioning pin 4g for expansion and contraction provided at the rear portion of the arm main body of the second arm 4b and spaced apart from the first arm 4a in at least two positions in the front-rear direction during expansion and contraction. A hook 10 to be locked at (4h) is provided. The hook 10 is formed with a claw protruding in the forward direction, and is fixed to the rear portion of the arm body.

  The positioning pins 4g and 4h provided on the first arm 4a side are, for example, the hooks 10 of the hook 10 being locked to the positioning pin 4g and the connecting portion 4d on the first arm side when retracting as shown in FIG. And the connecting portion 4e on the second arm side are connected by a pin. At this time, the other connecting portion 4f on the second arm side may be connected by providing a connecting portion corresponding to the first arm side, or may not be connected. In this way, when the second arm 4b is returned backward and the length of the arm 4 is shortened, the second arm 4b has the connecting portion 4e and the hook 10 connected to the connecting portion 4d of the first arm 4a. And it is locked to the positioning pin 4g and is fixed to the first arm 4a.

  When the arm 4 is extended, as shown in FIGS. 2 to 3, the hook of the hook 10 is locked to the positioning pin 4h on the first arm side, and the connecting portion 4d on the first arm side The connecting portion 4f on the second arm side is connected with a pin. The connecting portion 4e on the second arm side protrudes forward. As described above, when the length of the arm 4 is extended by protruding the second arm 4b forward, the second arm 4b is connected to the connecting portion 4d of the first arm 4a. And is fixed to the first arm 4a by being locked by the positioning pins 4h.

  In the second embodiment of the present invention, as shown in FIG. 4, in order to swing the second arm 4b in the front-rear direction, there is provided a driving device 11 by hydraulic drive installed in parallel with the parallel links 9a, 9b. It is what. Thus, the swinging operation of the second arm 4b can be easily performed by a remote control or the like.

It is a side view at the time of arm contraction which shows the arm expansion-contraction structure of the working machine 1 which concerns on this invention. It is a side view at the time of arm extension which shows the arm expansion-contraction structure of the working machine of the same invention. FIG. 4 is a partially enlarged detail side view showing the structure of the hook 10 of the arm 4. It is explanatory drawing which shows the rocking | fluctuation state of the arm 4 which concerns on 2nd Example. It is explanatory drawing (A) and (B) which show the structure of the arm of the working machine which concerns on a prior art example.

Explanation of symbols

1 working machine,
2 Work implement body,
3 Boom,
4 arms, 4a first arm,
4b second arm, 4c base,
4d connecting part, 4e connecting part,
4f connecting part, 4g, 4h positioning pin,
5 Attachments such as buckets
6 Hydraulic cylinder for boom,
7 Hydraulic cylinder for arm,
8 Hydraulic cylinder for bucket,
9a, 9b parallel links,
10 hooks,
11 Drive device.

Claims (2)

In the telescopic mechanism that expands and contracts the arm that is equipped on the tip side of the boom that can be raised and lowered in the work machine,
The arm is pivotally connected to the front end of the boom while being pivotally connected to the first arm connected to the telescopic device of the boom and a parallel link on the upper side of the first arm. And a second arm that is placed on the upper end surface of the first arm when it is movable and expanded and contracted in the front-rear direction with respect to the first arm,
The second arm has at least two connecting portions that are detachably connected to a mounting portion provided at a distal end portion of the first arm when the second arm is extended and contracted. A hook that is engaged with a positioning pin for expansion and contraction provided at least at two positions in the front-rear direction of the first arm during expansion and contraction.
Arm work telescopic structure characterized by. In order to swing the second arm, a hydraulically driven drive device installed parallel to the parallel link is provided,
The arm telescopic structure of the working machine according to claim 1.

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