JP2006045830A - Tilt cylinder damage preventing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tilt cylinder damage preventing device which can gently stop the rotation of a work tool so as to ease a shock at the time of stoppage of rotation of the work tool, to thereby protect not only a tilt cylinder but also component members near the same from being damaged. <P>SOLUTION: The work tool 11 is rotatably mounted on a front end of a working arm 6 via the tilt cylinder 20 formed of a hydraulic cylinder. Then a gripping device having a grip body 26 for gripping a mounting bracket 13 for mounting the work tool 11 on the working arm 6 or a gripped section 29 arranged on the bracket 13, is mounted on the working arm 6. Before a stroke end at the time of extension of the tilt cylinder 20, the grip body 26 grips the bracket 13 or the gripped section 29, and therefore motion of the work tool 11 is stopped by friction between abutting surfaces of both the bracket or the gripped section and the grip body. Since the work tool 11 is stopped by the friction, a shock is reduced, and therefore the component members are protected from being damaged. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  According to the present invention, in a work machine in which a work tool is rotatably attached to a tip of a work arm by a tilt cylinder that is a hydraulic cylinder, when the tilt cylinder is operated to a stroke end, the tilt cylinder is moved by inertia of the work tool. Furthermore, the present invention relates to a tilt cylinder damage preventing device that prevents the cylinder head (ring-shaped part attached to the tip of the cylinder cylindrical part) from being separated from the cylinder part of the cylinder when pulled in the extending direction.

  When, for example, a cage-shaped crushing tool is attached to the tip of the work arm of the work machine, the work arm is attached with a tilt cylinder that rotates the crushing tool so that the direction of the crushing tool can be changed. . When changing the crushing portion, the crushing operation is performed by operating the working arm and the tilt cylinder. During this crushing operation, if the tilt cylinder is extended to its stroke end and the crusher is operated, the tilt cylinder will be extended further due to the inertia caused by the rotation of the crusher when the tilt cylinder reaches the stroke end. There is a case in which an accident occurs in which the piston of the tilt cylinder strongly presses the inner surface of the cylinder head and the cylinder head is separated from the cylindrical portion of the cylinder.

  In order to prevent such an accident from occurring, Patent Document 1 discloses that an arm link connecting the tip of the piston rod of the tilt cylinder and the arm contacts the upper surface of the arm when the tilt cylinder extends near the stroke end. There is disclosed a structure in which a stopper roll which is in contact with the tilt cylinder and prevents further extension of the tilt cylinder is attached.

No. 7-28327

  As described in Patent Document 1, in the configuration in which the stopper roll is attached to the arm link, the piston rod of the tilt cylinder is mechanically stopped when the stopper roll of the arm link comes into contact with the arm. There is a problem that the impact when the extension stops is large, and there is a risk that components such as the stopper roll may be damaged.

  In view of the above-described problems, the present invention can moderately suppress the rotation of the work tool in the vicinity of the stroke end of the tilt cylinder. It is an object of the present invention to provide a tilt cylinder breakage prevention device that can prevent breakage of the surrounding components.

The tilt cylinder breakage prevention device according to claim 1 is a work machine in which a work tool is rotatably attached to a tip of a work arm by a tilt cylinder made of a hydraulic cylinder.
The work arm is provided with a gripping device having a gripping body for gripping a bracket for mounting the work tool on the arm or a gripped portion provided on the bracket,
Before the stroke end when the tilt cylinder is extended, the bracket or the gripped portion is gripped by the gripping body, and the movement of the work tool is suppressed by the friction of both contact surfaces. To do.

The tilt cylinder breakage prevention device according to claim 2 is described in claim 1.
The gripping device is connected to a first hydraulic cylinder that is operated by the operation of the tilt cylinder, and to the first hydraulic cylinder by a hydraulic pipe, and the bracket or the gripped portion is linked to the first hydraulic cylinder. And a second hydraulic cylinder for gripping and releasing the gripper by the gripping body.

  According to the first aspect of the present invention, the gripping body of the gripping device grips the bracket or the gripped portion of the work tool before reaching the stroke end when the tilt cylinder is extended, and the work tool is caused by friction between the contact surfaces of both. Since the rotation of the work tool is suppressed, the impact is reduced as compared with the case where the rotation of the work tool is stopped by the stopper, and the damage to the components can be avoided.

  According to the second aspect of the present invention, it is possible to configure a hydraulic circuit for gripping the work tool by the closed circuit of the two hydraulic cylinders by the arm without guiding the hydraulic oil from the work machine main body side. It can be easily configured without the need to provide additional hydraulic piping or valves for supplying and stopping hydraulic oil.

  FIG. 1 is a side view showing an example of a working machine provided with a tilt cylinder damage preventing device according to an embodiment of the present invention. In this working machine, a revolving unit 3 is installed on a traveling unit 1 via a revolving device 2, a power unit 4, a cab 5, and the like are installed on the revolving unit 3. Is installed. The working arm 6 of this example is a first arm 7 called a normal boom, a hydraulic cylinder 8 for raising and lowering, and a second arm called a normal arm attached to the tip of the first arm 7. An arm 9 and a hydraulic cylinder 10 for rotating the arm 9 are provided.

  Reference numeral 11 denotes a working tool attached to the tip of the working arm 6, and the working tool 11 in this example is a crushing tool. FIG. 2 is an enlarged side view of the main part of FIG. 1 showing the configuration of the tilt cylinder breakage preventing device and the work tool 11 of this embodiment, and FIG. 3 is a bottom view thereof. However, in FIG. 3, illustration of the lower structure of the work tool 11 is omitted. First, the working tool 11 and its mounting structure will be described with reference to FIGS. As shown in these drawings, the working tool 11 has a bracket 13 attached to the second arm 9 so as to be rotatable around a pin 12 and a turning device having a turning motor (not shown) attached to the bracket 13. 14 and a pair of crushing claws 19 attached to a swiveled body 15 of the swivel device 14 around a pin 16 so as to be opened and closed by a hydraulic cylinder 17. The crushing claw 19 has a cutter 19a for cutting a reinforcing bar and the like, and a projection 19b for crushing concrete or the like.

  Reference numeral 20 denotes a tilt cylinder for rotating the work tool 11, and a bottom side end portion thereof is connected to an upper surface of the second arm 9 by a pin 18. Reference numeral 21 denotes a first link which is interposed between the piston rod 20a of the tilt cylinder 20 and the second arm 9 by connecting pins 22 and 23 with pins 22 and 23, and 24 is a gap between the piston rod 20a and the bracket 13. This is a second link having both ends connected by pins 22 and 25.

  Next, the tilt cylinder damage preventing device will be described. Reference numeral 26 denotes a fixed gripping body, and 27 denotes a movable gripping body. These gripping bodies 26 and 27 are gripped portions provided so as to protrude toward the work machine main body (swivel body 3) side of the bracket 13, that is, the back side. 29 is gripped before reaching the stroke end when the tilt cylinder 20 is extended. The fixed grip body 26 is fixed to the lower surface of the second arm 9. The movable gripping body 27 is fixedly attached to a piston rod 30a of a hydraulic cylinder (second hydraulic cylinder) 30 fixed to the lower surface of the second arm 9.

  Reference numeral 31 denotes a hydraulic cylinder (first hydraulic cylinder) that operates in conjunction with the tilt cylinder 20 in accordance with the degree of extension of the tilt cylinder 20. In the present embodiment, the hydraulic cylinder 31 has its bottom The side is connected to the second arm 9 side by a pin 32, and the piston rod 31 a is attached to the first link 21 by a pin 33.

  FIG. 4 is a view for explaining the connection of the hydraulic piping between the hydraulic cylinders 30 and 31 and the operation of the gripping bodies 26 and 27. FIG. 4A shows the expansion / contraction state of the hydraulic cylinders 30 and 31 when the tilt cylinder 20 is in the contracted state and the work tool 11 is in the state shown by the two-dot chain line in FIG. 1, and FIG. A state in which the cylinder 20 extends to near the stroke end is shown. 4A and 4B, the hydraulic cylinders 30 and 31 have bottom chambers a and b connected by a hydraulic pipe 34 and rod chambers c and d connected by a hydraulic pipe 35, respectively. Yes.

  When the tilt cylinder 20 is contracted and the work tool 11 is rotated upward as shown by a two-dot chain line in FIG. 1, as shown in FIG. Is not between the gripping bodies 26 and 27, and the work tool 11 is not restrained by the gripping device. When the tilt cylinder 20 operates in the extending direction and extends to near the stroke end, the gripped portion 29 enters between the gripping bodies 26 and 27.

  On the other hand, as the tilt cylinder 20 is extended, the first link 21 is also rotated, and the hydraulic cylinder 31 is extended accordingly. Accordingly, the hydraulic cylinder 30 connected to the hydraulic cylinder 31 by the hydraulic pipes 34 and 35 contracts as shown in FIG. 4B, and the movable gripping body fixed to the piston rod 30 a of the hydraulic cylinder 30. 27 moves to the fixed gripping body 26 side and grips the gripped portion 29 between the gripping bodies 26, 27. Thereby, further rotation due to the inertia of the rotation of the work tool 11 is suppressed by the friction on the contact surface between the gripped portion 29 and the gripping bodies 26 and 27, and the piston of the tilt cylinder 20 is It is possible to prevent an accident that the cylinder head 20b is separated from the cylindrical portion 20c of the tilt cylinder 20 by strongly pressing the inner surface of the head 20b. It should be noted that, as a mode of suppressing the rotation of the work tool 11 by the gripping bodies 26 and 27 holding the gripped portion 29, the work tool 11 is rotated so that the rotation of the work tool 11 stops before the stroke end of the hydraulic cylinder 20. There are a mode for suppressing movement and a mode for reducing the impact at the stroke end by giving a rotation resistance so that the rotation speed becomes slow at the stroke end.

  As described above, in the present invention, before the end of the stroke of the tilt cylinder 20 is reached, the gripping bodies 26 and 27 of the gripping device grip the gripped portion 29 provided on the work tool 11, and the two come into contact with each other. Since the rotation of the work tool 11 is suppressed by the friction of the surface, the impact is reduced as compared with the case where the rotation of the work tool is stopped by the stopper, and the components such as the tilt cylinder 20 and the gripping device are damaged. I can be spared.

  When carrying out the present invention, a hydraulic pipe for sending hydraulic oil from the power unit 4 installed in the work machine body is attached to the work arm 6, and the hydraulic oil guided by the hydraulic pipe is used for the operation of the hydraulic cylinder 30. Although it may be used, the hydraulic cylinders 31 are operated by the movement of the tilt cylinder 20 as in the present embodiment, so that the two hydraulic cylinders 30 and 31 are closed without being guided to the working arm 6. Since the hydraulic circuit for gripping the work implement can be configured with the circuit, it is possible to easily configure without the need for providing the hydraulic piping attached to the working arm and the valves for supplying and stopping the hydraulic oil.

  When carrying out the present invention, the working arm 6 may be configured to include an add-on arm or a telescopic arm. In addition, the working tool 11 is not limited to the crushing tool, and the present invention is suitably used when a working tool having a large inertia is used, such as a heavy working tool having a large inertia due to rotation or a long working tool. Applied. In addition, the grip bodies 26 and 27 may directly grip the bracket 13 of the work tool 11, and both the grip bodies 26 and 27 may be configured as movable grip bodies.

It is a side view which shows an example of the working machine provided with the tilt cylinder damage prevention apparatus of one embodiment of this invention. It is a principal part enlarged side view of FIG. FIG. 3 is a bottom view of FIG. 2. It is a figure explaining the relationship between the hydraulic circuit of the tilt cylinder breakage prevention device of the present embodiment and the gripped portion and the gripping body, (A) when the tilt cylinder is in a contracted state, (B) is near the stroke end Shows the state when

Explanation of symbols

1: traveling body, 2: turning device, 3: turning body, 4: power unit, 5: cab, 6: working arm, 7: first arm, 8: hydraulic cylinder for hoisting, 9: second arm DESCRIPTION OF SYMBOLS 10: Hydraulic cylinder for rotation, 11: Work tool, 12: Pin, 13: Bracket, 14: Turning apparatus, 15: Turned object, 16: Pin, 17: Hydraulic cylinder, 18: Pin, 19: Crushing claw, 20: tilt cylinder, 21: first link, 22, 23: pin, 24: second link, 25: pin, 26: fixed gripper, 27: movable gripper, 29: gripped part, 30: first 2 hydraulic cylinders, 31: first hydraulic cylinder, 32, 33: pins, 34, 35: hydraulic piping

Claims (2)

In a work machine in which a work tool is rotatably attached to a tip of a work arm by a tilt cylinder made of a hydraulic cylinder,
The work arm is provided with a gripping device having a gripping body for gripping a bracket for mounting the work tool on the arm or a gripped portion provided on the bracket,
Before the stroke end when the tilt cylinder is extended, the bracket or the gripped portion is gripped by the gripping body, and the movement of the work tool is suppressed by the friction of both contact surfaces. Tilt cylinder breakage prevention device. In the tilt cylinder damage preventing device according to claim 1,
The gripping device is connected to a first hydraulic cylinder that is operated by the operation of the tilt cylinder, and to the first hydraulic cylinder by a hydraulic pipe, and the bracket or the gripped portion is linked to the first hydraulic cylinder. A tilt cylinder breakage prevention device comprising: a second hydraulic cylinder for gripping and releasing the gripper by the gripper.

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