JP4932674B2 - Natural fall prevention device for construction machinery - Google Patents

Description

  The present invention relates to a construction machine that includes a slide arm that is slidable on an arm and controls the position of the slide arm using a hydraulic cylinder.

Conventionally, in a slide arm mechanism such as a construction machine in which a slidable slide arm is provided on the arm and the position of the slide arm is controlled using a hydraulic cylinder, a lock device is provided on the slide arm. A slide arm mechanism is known (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 9-53608

  However, in the configuration described in Patent Document 1, since a hydraulic pressure is used for the locking operation of the locking device, a circuit for guiding the hydraulic pressure to the locking device is required. For this reason, there exists a disadvantageous aspect that a structure becomes complicated and cost becomes high.

  Therefore, an object of the present invention is to provide a construction machine that can prevent the slide arm from extending due to an oil leak in the hydraulic cylinder with a simple configuration.

In order to achieve the above object, the present invention is a construction machine comprising a slide arm slidable on an arm and controlling the position of the slide arm using a hydraulic cylinder,
The width gradually increases from the tip and exceeds the maximum width part, and the width gradually decreases, and the engaged part reaches the neck part having a width smaller than the maximum width part and is urged toward each other and engaged. And an engagement portion having a pair of claw portions that engage with the engaged portion at times.
The engaging portion is configured in a U-shape in which arm portions extending from the pair of claw portions are integrally coupled at a position away from the claw portion, or the engaging portion extends from the pair of claw portions. The arm portions are each pivotally supported in the middle, and a biasing member is provided on the opposite side of the claw portion across the pivot support position,
One of the engaged part and the engaging part is provided on a slide arm sliding surface of an arm, and the other of the engaged part and the engaging part is the engaged part and the engaging part. Provided at the end of the slide arm so as to be engageable with one of the engaging portions;
When the top dead center of the sliding stroke of the slide arm is reached, the neck portion of the engaged portion is engaged with the pair of claw portions of the engaging portion,
When the slide arm receives a driving force in the extending direction by the hydraulic cylinder, the engagement between the neck portion of the engaged portion and the pair of claw portions of the engaging portion is released.

  ADVANTAGE OF THE INVENTION According to this invention, the construction machine which can prevent the extension of a slide arm by the oil leak in a hydraulic cylinder with a simple structure is obtained.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram schematically showing an entire construction machine 1 according to an embodiment of the present invention. The construction machine 1 according to the present embodiment is a power shovel, and an upper swing body 3 is rotatably provided on a lower traveling body 2. A boom 4 is swingably provided on the upper swing body 3 in the vertical direction, and an arm 5 is swingably attached to the tip of the boom 4. The rotation angle of the boom 4 is controlled by the boom cylinder 6, and the rotation angle of the arm 5 is controlled by the arm cylinder 7. A slide arm 9 having a bucket 8 at its tip is slidably provided on the upper surface of the arm 5. Expansion and contraction of the slide arm 9 is controlled by a slide arm cylinder 10. The bucket 8 has a rotation angle controlled by a bucket cylinder 11.

  FIG. 2 is a diagram showing a configuration related to the slide arm 9 of the construction machine 1 and shows an unlocked state of the slide arm 9. FIG. 3 shows the locked state of the slide arm 9.

  The slide arm 9 is guided by a slide guide 18. One end of the slide arm cylinder 10 is attached to the inner center portion of the slide arm 9, and the other end is attached to an attachment member 12 fixed to the rear end portion of the arm 5.

  An engaging portion 70 is provided at the rear end portion of the arm 5. An engaged portion 16 is provided at the rear end portion of the slide arm 9. As shown in FIG. 3, the engaged portion 16 of the slide arm 9 moves when the slide arm 9 moves (retracts) in the contracting direction and substantially reaches the top dead center of the sliding stroke. The engagement portion 70 is mechanically engaged. The engagement between the engaged portion 16 of the slide arm 9 and the engaging portion 70 of the arm 5 is performed by the slide arm 9 receiving a driving force (for example, a driving force of a predetermined value or more) in the extending direction by the slide arm cylinder 10. It is configured to be released as long as the driving force is not generated while being released mechanically. As a result, it is possible to prevent the slide arm 9 from being naturally extended due to an oil leak that may occur when performing continuous excavation or long-time suspension work. When the engagement between the engaged portion 16 of the slide arm 9 and the engaging portion 70 of the arm 5 is released, the slide arm 9 freely expands and contracts under the control of the slide arm cylinder 10 as usual. be able to.

  FIG. 4 is a diagram illustrating an example of the relationship between the engaged portion 16 of the slide arm 9 and the engaging portion 70 of the arm 5. In the example shown in FIG. 4, the engaged portion 16 of the slide arm 9 gradually increases in width from the sharp tip portion from the tip portion to the rear, and then gradually decreases in width and has a neck portion 16 a. Yes. The engaging portion 70 of the arm 5 has a U-shape, and two U-shaped tip portions have claws 72 that protrude toward each other.

  In the example shown in FIG. 4, when the slide arm 9 moves in the contracting direction, the tip of the engaged portion 16 enters the engaging portion 70 from between the claws 72 of the engaging portion 70. At this time, the tip of the engaged portion 16 widens the gap between the claws 72 as the slide arm 9 moves in the contracting direction (the engaging portion 70 bends outward). When the slide arm 9 further moves in the contracting direction and the portion of the maximum width of the engaged portion 16 passes between the claws 72, the gap between the claws 72 returns to the original position, and the claws 72 are engaged with the engaging portion 16. The neck portion 16a is clamped from both sides to engage (lock). When such engagement occurs, natural extension of the slide arm 9 due to oil leakage can be prevented. On the other hand, when the user starts the operation and performs an operation of extending the slide arm 9, a force moves in the extending direction of the slide arm 9, thereby widening the gap between the claws 72, and the engaged portion 16 is engaged. The engagement at the joint 70 is released.

  5A and 5B are diagrams showing some examples of the configuration of the claw 72 of the engaging portion 70 of the arm 5. FIG. 5 shows a locked state in which the engaged portion 16 is engaged by the claw 72 of the engaging portion 70 of the arm 5. In FIG. 5, only the configuration on the left half side from the center line is shown using left-right symmetry.

  In the example shown in FIG. 5A, the claw 72 includes a rotating roller. In this case, the rotation of the rotary roller reduces the friction between the claw 72 and the engaged portion 16 during engagement and disengagement, and improves durability. In the example shown in FIG. 5 (B), the claw 72 has a so-called key hand shape, and the width of the claw 72 is widened by the movement of the engaged portion 16 both when engaged and when disengaged. This improves the reliability of the engagement and disengagement operations.

  FIG. 6 is a diagram showing an alternative example of the configuration of the engaging portion 70 of the arm 5. In the example shown in FIG. 6, the engaging portion 70 of the arm 5 can be rotated around the pin 74, and the clearance between the claws 72 is variable by the rotation. As shown in FIG. 6B, when the tip of the engaged portion 16 enters the engaging portion 70 from between the claws 72 of the engaging portion 70, rotation around the pin 74 occurs and The gap between 72 widens. At this time, the spring 76 is bent as shown in FIG. When the slide arm 9 further moves in the contracting direction and the maximum width portion of the engaged portion 16 passes between the claws 72, the restoring force of the spring 76 causes the claws as shown in FIG. The gap between 72 returns to its original state, and the claw 72 clamps the neck portion 16a of the engaging portion 16 from both sides to engage (lock). In the example shown in FIG. 6, the spring 76 is arranged so as to contract when the rotation of the engaging portion 70 around the pin 74 occurs, but it may be arranged so as to extend. In addition, when the portion of the maximum width of the engaged portion 16 passes between the claws 72, the normal state (unlocked state) shown in FIG. 6 (A) is restored by the restoring force (compression force) of the spring 76.

  According to the construction machine 1 according to the present embodiment described above, the following excellent effects can be obtained.

  According to the present embodiment, as described above, the locked and unlocked state between the slide arm 9 and the arm 5 is the engagement operation between the engaged portion 16 and the engaging portion 70 having a simple configuration, and Since this is realized by the disengagement operation, the natural extension of the slide arm 9 due to oil leakage can be prevented at low cost. That is, the engaging operation and the disengaging operation between the engaged portion 16 and the engaging portion 70 of the arm 5 are mechanically realized without using hydraulic pressure, so that it is not necessary to add a hydraulic circuit or the like. In addition, the configuration can be prevented from becoming complicated. Further, according to the present embodiment, the natural extension of the slide arm 9 due to oil leak can be prevented, so that it is not necessary to set an oversized spool or a holding valve.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  For example, in the above-described embodiment, the engaged portion 16 of the slide arm 9 has a rhombus-shaped tip, and the engaging portion 70 of the arm 5 has a claw 72. May be. That is, the engaged portion 16 of the slide arm 9 may have the form of the engaging portion 70, and the engaging portion 70 of the arm 5 may have the form of the engaged portion 16.

  In the above-described embodiment, the engaging portion 70 of the arm 5 is provided on the arm 5 itself, but may be provided on another member that is integrally coupled to the arm 5. For example, the engaging portion 70 may be attached to the attachment member 12.

  In the above-described embodiment, the slide arm 9 is a slide arm mechanism that is slidably provided outside the arm 5, but the present invention can be applied to any type of slide arm mechanism. For example, the present invention can be applied to a telescopic slide arm mechanism in which a slide arm is slidably provided in the arm.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows schematically the whole one Example of the construction machine 1 by this invention. FIG. 2 is a view showing a configuration related to the slide arm 9 of the construction machine 1 and showing an unlocked state of the slide arm 9. It is a figure which shows the locked state of the slide arm. It is a figure which shows an example of the relationship between the to-be-engaged part of the slide arm 9, and the engaging part 70 of the arm 5. FIG. It is a figure which shows some examples of a structure of the nail | claw 72 of the engaging part 70 of the arm 5. FIG. It is a figure which shows the alternative example of a structure of the engaging part of the arm.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Construction machine 2 Lower traveling body 3 Upper turning body 4 Boom 5 Arm 8 Bucket 9 Slide arm 10 Slide arm cylinder 16 Engagement part 70 Engagement part 72 Claw

Claims (3)

A construction machine comprising a slidable slide arm on an arm and controlling the position of the slide arm using a hydraulic cylinder,
The width gradually increases from the tip and exceeds the maximum width part, and the width gradually decreases, and the engaged part reaches the neck part having a width smaller than the maximum width part and is urged toward each other and engaged. And an engagement portion having a pair of claw portions that engage with the engaged portion at times.
The engaging portion is configured in a U shape in which arms extending from the pair of claw portions are integrally coupled at a position away from the claw portion ,
One of the engaged part and the engaging part is provided on a slide arm sliding surface of an arm, and the other of the engaged part and the engaging part is the engaged part and the engaging part. Provided at the end of the slide arm so as to be engageable with one of the engaging portions;
When the top dead center of the sliding stroke of the slide arm is reached, the neck portion of the engaged portion is engaged with the pair of claw portions of the engaging portion,
Slide arm when subjected to a driving force in the expanding direction by the hydraulic cylinder, the engagement between the pair of claw portions of the engaging portion and the neck portion of the engaging portion is released, construction machinery. A construction machine comprising a slidable slide arm on an arm and controlling the position of the slide arm using a hydraulic cylinder,
The width gradually increases from the tip and exceeds the maximum width part, and the width gradually decreases, and the engaged part reaches the neck part having a width smaller than the maximum width part and is urged toward each other and engaged. And an engagement portion having a pair of claw portions that engage with the engaged portion at times.
The engaging portion, said arm portion extending from the pair of claw portions are respectively pivotally supported in the middle, the biasing member is provided, et al is on the opposite side of the pawl portion across the pivotally supported position,
One of the engaged part and the engaging part is provided on a slide arm sliding surface of an arm, and the other of the engaged part and the engaging part is the engaged part and the engaging part. Provided at the end of the slide arm so as to be engageable with one of the engaging portions;
When the top dead center of the sliding stroke of the slide arm is reached, the neck portion of the engaged portion is engaged with the pair of claw portions of the engaging portion,
Slide arm when subjected to a driving force in the expanding direction by the hydraulic cylinder, the engagement between the pair of claw portions of the engaging portion and the neck portion of the engaging portion is released, construction machinery. The pair of claws are rotary rollers that are pivotally supported at the tips of the claws, and convert the sliding resistance when engaged with the engaged part and when released from the engaged part into rotational movement. The construction machine according to claim 1 or 2 , comprising a rotating roller.

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