JP2005207195A - Working machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a working machine wherein the minute operation performance of a blade is enhanced. <P>SOLUTION: The blade of a power angle tilt dozer is provided so as to be operable by an angle cylinder 2 in terms of an angle and provided so as to be tiltable by a tilt cylinder 3. One of the angle cylinder 2 and the tilt cylinder 3 is selected by a change-over valve 46, and each operation is controlled by an angle tilt control valve 44. The angle tilt control valve 44 is pilot-controlled by an angle tilt pilot valve 45 outputting pilot pressure in response to an operation amount. A switch transmitting an electric signal for switching the change-over valve through a solenoid valve is provided on a blade lever manually operating the angle tilt pilot valve 45. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a work machine provided with a blade.

  For the lifting arm pivotably supported by the airframe, the blade can be tilted and rotated via a tilt shaft and a tilt cylinder, and the angle can be rotated via an angle shaft and an angle cylinder. There is a blade working machine in which a switching operation between a blade tilt rotation operation and an angle rotation operation is performed by an operation switch provided in a control unit.

  In this blade working machine, the operation switch can be selectively switched between a tilt rotation operation and an angle rotation operation, and has a neutral position that disables both operations, and the tilt rotation operation and the angle rotation. There is a blade operation switch structure composed of a rotation angle adjuster for setting an operation rotation angle (see, for example, Patent Document 1).

  FIG. 9 shows a hydraulic circuit for a conventional power angle tilt dozer (hereinafter referred to as “PAT”) operated by a switch as described above. As shown in FIGS. This is a circuit for controlling the blade 4 provided so that it can be moved up and down by the blade lifting cylinder 1, angled by the angle cylinder 2 and tilted by the tilt cylinder 3.

  As shown in FIG. 10 and FIG. 12, an operation knob 6 having an electric 4-way switch 6a, 6b, 6c, 6d for angle / tilt operation is provided at the tip of the blade lever 5 for raising and lowering the blade. When these switches 6a, 6b, 6c, and 6d are pressed, signals from the switches 6a, 6b, 6c, and 6d are calculated by a PAT controller (not shown), and output signals from the PAT controller are The angle cylinder / tilt cylinder switching electromagnetic valve 7s and the cylinder expansion / contraction switching electromagnetic valve 8s installed in the hydraulic circuit shown in FIG.

  That is, as shown in FIG. 10, by operating either one of a pair of upper and lower switches 6a and 6b provided on the upper part of the blade lever 5, the angle cylinder / tilt cylinder switching shown in FIG. The solenoid valve 7s is turned on, the pilot pump pressure is supplied to the left side of the switching valve 7, the switching valve 7 is switched to the angle cylinder side, and the solenoid valve 8s for cylinder expansion / contraction switching is controlled on / off. The angle / tilt control valve 8 is controlled to be switched to the neutral position, one switching position or the other switching position by the on / off type pilot pressure accompanied with the directionality from the electromagnetic valve 8s, and the pair of angle cylinders 2 are controlled. As shown in FIG. 11, control is performed to the left-justified angle state or the right-justified angle state.

  Similarly, as shown in FIG. 12, the angle cylinder / tilt cylinder switching shown in FIG. 9 is performed by operating one of a pair of left and right switches 6c, 6d provided on the upper part of the blade lever 5. The solenoid valve 7s is turned off, the switching valve 7 is returned to the tilt cylinder 3 side shown in FIG. 9, and the cylinder expansion / contraction switching solenoid valve 8s is controlled to be turned on / off. The angle / tilt control valve 8 is switched to the neutral position, one switching position or the other switching position by the on / off type pilot pressure with directionality, and the tilt cylinder 3 is tilted to the left as shown in FIG. Control to the state or tilted to the right.

In addition, there is a work machine in which four switches are provided on the operation lever so that the blade is angle-operated by operation of a pair of opposed switches and the blade is slid by operation of another pair of opposed switches. (For example, refer to Patent Document 2).
JP 2000-240093 (first page, FIG. 4) JP-A-8-270017 (first page, FIG. 1)

  Thus, conventionally, since the hydraulic control of the angle cylinder 2 and the tilt cylinder 3 of the blade 4 is based on the full open / close control by the on / off signals of the switches 6a, 6b, 6c, 6d of the operation knob 6, the blade There was a problem that the fine operation of 4 was difficult and workability was not good.

  The present invention has been made in view of these points, and an object of the present invention is to provide a work machine capable of improving the fine operability of the blade.

  According to the first aspect of the present invention, there are provided an airframe, a blade provided to the airframe so as to be capable of an angle operation and a tilt operation, an angle cylinder for operating the blade at an angle, a tilt cylinder for operating the tilt operation, an angle cylinder and a tilt cylinder. An angle / tilt control valve that controls each via a selector valve that selects one, and an angle / tilt pilot valve that controls the angle / tilt control valve with a pilot pressure corresponding to the operation amount, An angle / tilt pilot valve that controls the angle / tilt control valve with pilot pressure according to the amount of operation is provided. Improves.

  According to a second aspect of the present invention, in the work machine according to the first aspect, a blade lever for manually operating at least the angle / tilt pilot valve, and a switching valve provided on the blade lever for selecting one of the angle cylinder and the tilt cylinder. This switch is equipped with a switch that transmits an electrical signal for switching operation, and manually operates the angle / tilt pilot valve with the blade lever and operates the switch with a hand that holds the blade lever. Since the switching valve for selecting one of the angle cylinder and the tilt cylinder is switched by the electrical signal transmitted from the motor, the operability is good.

  According to the first aspect of the present invention, the angle / tilt pilot valve for controlling the angle / tilt control valve by the pilot pressure corresponding to the operation amount is provided. In addition, the angle can be finely operated, and the leveling workability can be improved.

  According to the second aspect of the invention, the angle / tilt pilot valve is manually operated by the blade lever, the switch is operated by a hand holding the blade lever, and the angle cylinder and Since the switching valve for selecting one of the tilt cylinders is switched, the operability can be improved.

  The present invention will be described below with reference to one embodiment shown in FIGS.

  FIG. 2 shows a hydraulic excavator as a work machine. An upper swing body 13 is turnably provided on a lower travel body 11 as a machine body via a swing bearing portion 12, and a power angle tilt dozer ( A blade 4 used for earth removal work or leveling work is attached via a push arm 14 constituting a power angle tilt (hereinafter referred to as “PAT”). A working device 15 used for the attachment work is mounted.

  For this work device 15, a driver's seat 16 on which an operator sits is provided on the upper swing body 13, and consoles 17 are disposed on both left and right sides of the driver's seat 16, and on these consoles 17, work is performed. An operation lever 18 for operating the device 15 is provided, and a blade lever 19 for operating the blade 4 is provided in the vicinity of the right console 17.

  As shown in FIG. 3, the blade 4 is provided so as to be moved up and down by a blade lifting cylinder 1 provided between a bracket 21 on the lower traveling body 11 and a bracket 22 in the distal end portion of the push arm 14. A shaft member that connects the tip of the push arm 14 and the center of the blade 4 by a pair of angle cylinders 2 provided between the left and right brackets 23 of the arm 14 and the left and right brackets 24 of the blade 4. (Not shown) is provided so that it can be operated at an angle around the lower end of the tilt cylinder 3 pivotally supported between a bracket 25 attached to the upper part of the tip of the push arm 14 and a bracket 26 on one side of the blade 4. The shaft member 27 is provided so as to be tiltable.

  As shown in FIG. 4, the blade lever 19 has a hollow operation knob 32 attached to an upper portion of a pipe-shaped lever body 31, and an on / off type for angle / tilt switching is provided inside the operation knob 32. A button switch 33 is provided as a switch, and an operation button 34 for turning on / off the button switch 33 is provided at a position where the operation knob 32 can be operated with an index finger. The electric wiring 35 of the button switch 33 is drawn out from the inside of the lever main body 31 through the lower small hole 36, and is connected to an unillustrated battery and an electromagnetic valve 47 for switching the angle cylinder / tilt cylinder circuit.

  FIG. 1 shows a hydraulic circuit for controlling the blade lifting cylinder 1, the angle cylinder 2 and the tilt cylinder 3. The blade lifting cylinder 1 is controlled by directional control of the hydraulic pressure supplied from the main hydraulic power source 41 to the blade lifting cylinder 1. A blade lift control valve 42 that controls the expansion and contraction of the blade 1 is provided, and a two-way blade lift pilot valve 43 is provided on the left and right pilot lines 42a and 42b of the blade lift control valve 42. The pilot valve 43 for raising and lowering the blade outputs a pilot pressure corresponding to the amount of manual operation in the front-rear direction of the blade lever 19 to the blade elevation control valve 42 to control the direction and amount of displacement of the blade elevation control valve 42. This is a so-called remote control valve.

  The blade lift control valve 42 is provided with a blade float position 42F. The blade float position 42F constitutes a float mechanism that can be balanced even when the hydraulic circuit is closed, and the head side chamber and the rod side chamber of the blade lifting cylinder 1 are communicated with the tank T so that pressure does not act. By doing so, the blade 4 can be freely moved up and down by its own weight without being fixed.

  In addition, an angle / tilt control valve 44 for controlling the direction of the hydraulic pressure supplied from the main hydraulic pressure source 41 to control the expansion / contraction operation of the angle cylinder 2 or the tilt cylinder 3 with respect to the angle cylinder 2 and the tilt cylinder 3 is provided. Two-way angle / tilt pilot valves 45 are provided on the left and right pilot lines 44a, 44b of the angle / tilt control valve 44. This angle / tilt pilot valve 45 outputs a pilot pressure corresponding to the amount of manual operation of the blade lever 19 in the left-right direction to the angle / tilt control valve 44, and the direction and amount of displacement of this angle / tilt control valve 44 This is a so-called remote control valve for controlling the motor.

  In the line between the angle / tilt control valve 44 and the angle cylinder 2 and the tilt cylinder 3, a switching valve 46 for selecting one of the angle cylinder 2 or the tilt cylinder 3 is provided. The pilot line 46a is provided with an electromagnetic valve 47 for switching an angle cylinder / tilt cylinder circuit. The solenoid valve 47 is turned on / off based on an electric signal transmitted from a button switch 33 provided on the blade lever 19, and guides the pilot pressure supplied from the pilot hydraulic power source P to the pilot line 46a when turned on. The switching valve 46 is switched from the tilt cylinder 3 side shown in FIG. 1 to the angle cylinder 2 side. In the circuit diagram of FIG. 1, 48 is a relief valve, and T is a common tank.

  As shown in FIG. 5, the blade raising / lowering pilot valve 43 includes a rotation operation body 52 that is directly or indirectly rotated by the blade lever 19 in the cover body 51 via a linkage, a wire, or the like. A detent mechanism 54 that is pivotally supported by a shaft member 53 and that holds a rotation angle with respect to the rotation operation body 52 is provided. A pair of slidably fitted rods 55 are brought into contact with each other, and engaging members 55a are respectively engaged with the lower portions of these rods 55. Further, these engaging members 55a are inserted into the valve body 56. A pair of slidably fitted spools 57 are respectively engaged, and each engaging member 55a and each rod 55 are biased upward by a large spring 58a, while each spool 57 is a small spring. These spools 57 and valve body 56 are biased downward by 58b. The passage 59 forms a pressure reducing valve that supplies the pilot pressure supplied from the pilot hydraulic power source P to the pilot lines 42a and 42b of the blade lifting / lowering control valve 42 in accordance with the rotation operation amount of the rotation operation body 52. ing.

  As shown in FIG. 6, the angle / tilt pilot valve 45 is pivoted to the upper bracket 61 a of the cover body 61 by the blade lever 19 directly or indirectly via a linkage, a wire or the like. The body 62 is pivotally supported by a shaft member 63, and a pair of rods 65 slidably fitted to the cover body 61 are brought into contact with the lower side surfaces of the left and right portions of the rotational operation body 62. Engaging members 65a are respectively engaged with the lower portions of the rods 65, and a pair of spools 67 slidably fitted in the valve main body 66 are respectively engaged with the engaging members 65a. The engaging members 65a and the rods 65 are biased upward by the large springs 68a, while the spools 67 are biased downward by the small springs 68b. From the pilot hydraulic source P by the passage 69 Pilot line 44a of the angle and tilt control valve 44 to supply pilot pressure in accordance with the rotation operation amount of the rotational operation body 62, pressure reducing valve is formed to be supplied to 44b.

  Next, the function and effect of this embodiment will be described.

  By operating the blade lever 19 in the front-rear direction, the blade 4 is operated in the up-and-down direction. Since the / tilt switching operation can be facilitated, simultaneous operation of the vertical movement of the blade 4 and the angle or tilt can be facilitated.

  That is, when the blade lever 19 is pushed forward, the pilot pressure is applied from the blade lifting pilot valve 43 to the pilot line 42b, the blade lifting control valve 42 is switched to the lowered position 42D, and the blade lifting cylinder 1 is extended. Thus, the blade 4 can be lowered.

  When the blade lever 19 is pushed forward as far as possible, the blade lift control valve 42 is switched to the blade float position 42F, and the head side chamber and the rod side chamber of the blade lift cylinder 1 communicate with the tank T, and pressure is applied to these. Since it does not act, it is possible to level the ground while freely moving up and down by the weight of the PAT dozer without fixing the blade 4 without being affected by the pitching of the vehicle, which is suitable for leveling work.

  On the other hand, when the blade lever 19 is pulled, the pilot pressure acts on the pilot line 42a from the blade lift pilot valve 43, the blade lift control valve 42 is switched to the lift position 42U, and the blade lift cylinder 1 is contracted. The blade 4 can be raised.

  When the blade lever 19 is operated in the left-right direction without pressing the button switch 33 of the blade lever 19, the solenoid valve 47 is in the off state shown in FIG. 1, and the switching valve 46 is also in the switching state shown in FIG. Since the angle / tilt pilot valve 45 pilot-operates the angle / tilt control valve 44, the tilt cylinder 3 can be expanded and contracted to tilt the blade 4 around the shaft member 27.

  On the other hand, when the blade lever 19 is operated in the left-right direction while the button switch 33 of the blade lever 19 is being pressed, the electromagnetic valve 47 is switched on and the switching valve 46 is switched to the opposite side. Since the angle / tilt pilot valve 45 pilot-operates the angle / tilt control valve 44, the blade 4 can be angle-operated by extending and contracting the pair of angle cylinders 2 in opposite directions.

  In this way, the hydraulic control of each cylinder that performs the angle / tilt operation of the blade 4 is controlled by a hydraulic remote controller that outputs a pilot pressure corresponding to the operation amount from an on / off type pilot system using a conventional solenoid valve 8s (FIG. 9). The angle / tilt pilot valve 45 is used to control the angle / tilt control valve 44 with the pilot pressure corresponding to the operation amount of the blade lever 19, instead of the valve-type angle / tilt pilot valve 45. The fine tilt operation and the fine angle operation of the blade 4 can be performed, and the leveling workability by the blade 4 can be improved.

  In addition, the angle / tilt pilot valve 45 is manually operated by the blade lever 19, and the button switch 33 is operated by a hand holding the operation knob 32 of the blade lever 19, and an electric signal transmitted from the button switch 33 is used. Since the switching valve 46 for selecting one of the angle cylinder 2 and the tilt cylinder 3 is switched via the electromagnetic valve 47, the operability is good.

  As described above, the blade lift control valve 42 and the angle / tilt control valve 44 are operated by operating the blade control pilot valve 43 and the angle / tilt pilot valve 45 of the hydraulic remote control valve system with one blade lever 19. Since the pilot control is performed, the fine operation of the raising / lowering operation, the tilt operation, and the angle operation of the blade 4 can be easily performed.

  Next, another embodiment will be described with reference to FIGS.

  This embodiment eliminates the blade lifting pilot valve 43 in the embodiment shown in FIG. 1, and uses a blade lever 19 to transmit the blade lever 19 swinging in the front-rear direction. The spool 42s of the blade lift control valve 42 can be directly pulled via the cable 71 and the motion conversion mechanism 72.

  As shown in FIG. 8A, in the motion conversion mechanism 72, a lower connection fitting 74 integrated with a wire 73 of a push-pull cable 71 for raising and lowering a blade is fitted to one end portion of a rotary shaft 75 to be screwed 76. The rotating shaft 75 is rotatably connected to a lower lever 77 integrated by a pin 78 by a cylindrical bearing member 82 fixed to a member 81 integrated with a swing frame in the upper swing body 13. In addition, an upper lever 83 is fitted to the other end of the rotary shaft 75 and integrated by welding or the like, and the rotary motion of the rotary shaft 75 is reciprocated at the upper end of the upper lever 83. One end portion of the link 84 to be converted is rotatably attached by a pin 85, and the spool 42s of the blade elevation control valve 42 shown in FIG. Has been.

  When the blade lever 19 is pushed forward of the vehicle, the spool 42s of the blade lifting control valve 42 can be directly pulled via the wire 73 of the blade lifting push-pull cable 71 and the motion conversion mechanism 72, and the blade lifting control valve 42 can be operated. Is switched to the lowered position 42D, the blade raising / lowering cylinder 1 is extended and the blade 4 can be lowered, and further, when the blade lever 19 is pushed to the maximum in front of the vehicle, the spool 42s of the blade raising / lowering control valve 42 is Is pulled to the maximum position, the blade lifting control valve 42 is switched to the blade float position 42F. On the other hand, when the blade lever 19 is pulled rearward, the spool 42s of the blade lifting control valve 42 can be directly pushed through the wire 73 and the motion conversion mechanism 72, and the blade lifting control valve 42 is switched to the rising position 42U. The blade lifting cylinder 1 can be contracted to raise the blade 4.

1 is a circuit diagram showing an embodiment of a hydraulic circuit for a dozer in a work machine according to the present invention. It is a side view of a working machine same as the above. It is a top view which shows the power angle tilt dozer of a working machine same as the above. It is a front view which shows the blade lever of a working machine same as the above. It is sectional drawing which shows the pilot valve for blade raising / lowering of a working machine same as the above. It is sectional drawing which shows the pilot valve for angle / tilt of a working machine same as the above. It is a circuit diagram which shows other embodiment of the hydraulic circuit for dozers in the working machine which concerns on this invention. (A) is a perspective view of the motion conversion mechanism for operating the blade raising / lowering control valve in the hydraulic circuit for dozers, and (b) is a sectional view thereof. It is a circuit diagram which shows the hydraulic circuit for dozers in the conventional working machine. It is a perspective view which shows the blade lever in the case of carrying out angle operation of the conventional power angle tilt dozer, and its periphery. It is a perspective view which shows angle operation of a power angle tilt dozer. It is a perspective view which shows the blade lever in the case of tilting operation of the conventional power angle tilt dozer, and its periphery. It is a perspective view which shows tilt operation of a power angle tilt dozer.

Explanation of symbols

2 Angle cylinder 3 Tilt cylinder 4 Blade
11 Undercarriage as the aircraft
19 Blade lever
33 Button switch as a switch
44 Angle / tilt control valve
45 Pilot valve for angle and tilt
46 Switching valve

Claims (2)

The aircraft,
A blade provided to the aircraft so that it can operate at an angle and tilt;
An angle cylinder for tilting the blade and a tilt cylinder for tilting;
An angle / tilt control valve for controlling each of the angle cylinder and the tilt cylinder via a switching valve for selecting one of these; and
An angle / tilt pilot valve for controlling an angle / tilt control valve with a pilot pressure corresponding to an operation amount. A blade lever for manually operating at least an angle / tilt pilot valve;
2. A work machine according to claim 1, further comprising: a switch that is provided on the blade lever and that transmits an electrical signal for switching a switching valve for selecting one of an angle cylinder and a tilt cylinder.

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