JP2008199975A - External hydraulic pressure removing device for working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the workability in attaching an implement to a hydraulic top-link of a working vehicle adopting a hydraulic top-link for a top-link having a three-point link mechanism for attaching an implement and having an external hydraulic pressure operation lever on the operation part to operate a direction control valve of an external hydraulic power take out device to supply a hydraulic oil to the hydraulic top-link. <P>SOLUTION: An auxiliary operation lever 33a enabling direct operation of a valve spool 27a from the outside of the vehicle is provided by being directly connected to the valve spool 27a of the direction control valve 21a of the external hydraulic power take out device 21 to supply a hydraulic oil to a hydraulic top-link 31. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a work vehicle provided with an external hydraulic pressure take-out device that supplies hydraulic oil to a hydraulic actuator of a work machine and a hydraulic actuator provided in a connection mechanism of the work machine.

Conventionally, in a crawler tractor which is an example of a work vehicle, a towing work can be performed by attaching a work machine such as a wing harrow, a big baler, and a plow to the rear part of the machine body. It has a hydraulic operation part which operates via. For example, in the case of a wing harrow, different hydraulic actuators are used for the rake drive device, the left and right wing folding devices, etc., and the supply of hydraulic oil to the desired hydraulic actuator is controlled by the multiple direction control provided on the crawler tractor side This is done via an external hydraulic pressure take-out device consisting of a valve (see Patent Document 1).
Japanese Patent Laying-Open No. 2004-162841 (page 3-4, FIG. 7)

  Many of the multiple directional control valves constituting the external hydraulic pressure take-out device are disposed at the rear of the fuselage, and, as shown in FIG. 4, an external hydraulic control lever 24a, 24b is provided, and multiple directional control valves 21a corresponding to the external hydraulic operation levers 24a and 24b are provided via the wires 25a and 25b and the swinging arms 26a and 26b linked to the external hydraulic operation levers 24a and 24b. The valve spools 27a and 27b included in the slidable member 21b can be operated in and out (sliding).

  Furthermore, a hydraulic hose is connected to both ports via a quick coupler that can be connected to the pressure port and return port of the multi-directional valve, and the other end of these hydraulic hoses is connected to the cylinder port of the desired hydraulic actuator. Thus, as described above, the hydraulic operation unit provided in the work implement can be operated in a desired direction in correspondence with the operation direction of the external hydraulic operation levers 24a and 24b.

  In addition, a three-point link mechanism consisting of a turnbuckle top link for mounting the above-described work implement and a left and right lower link supported via a lift rod connected to a lift arm is always installed in the lower rear part of the cabin. However, in recent years, a hydraulic top link has been adopted instead of the turnbuckle top link in order to facilitate the mounting and adjustment work of the work machine. That is, this hydraulic top link is connected to the multiple direction control valve constituting the external hydraulic pressure take-out device via a hydraulic hose, and the piston rod of the top link is connected to the desired direction via the external hydraulic operation lever 24a. It can be extended and retracted.

However, in this case, when connecting the tip of the piston rod of the hydraulic top link to the top mast or the like of the counterpart work machine, the operator first connects the stationary work machine to the left and right lower links, The piston rod is extended or contracted while operating the external hydraulic operation lever 24a inside, and the tip of the piston rod must be aligned with a connection point such as a top mast of the work machine. Is forced to move up and down repeatedly to operate the external hydraulic control lever 24a.
Then, after connecting the tip of the piston rod and the top mast of the work implement using a connection pin, the left and right lower links are lifted via lift cylinders to adjust the front / rear posture of the work implement to a predetermined work posture. In the state where the work implement is pulled away from the ground, it is necessary to operate the external hydraulic control lever 24a again to extend or contract the piston rod. At this time, the operator operates the external hydraulic control lever 24a again. It was necessary to repeatedly ascend and descend the cabin, and the crawler tractor was a large work vehicle, so the workability was extremely poor.

  An object of the present invention is to solve the above-mentioned problem, and in a work vehicle having an external hydraulic operation lever for operating a directional control valve of an external hydraulic pressure take-out device arranged in a fuselage in a control unit, the direction An auxiliary operation lever capable of directly operating the control valve from outside the apparatus is provided.

  According to the present invention, by providing an auxiliary operation lever capable of directly operating the direction control valve of the external hydraulic pressure take-out device from the outside of the machine, for example, in the vicinity of the external hydraulic pressure take-out device arranged at the rear part of the machine body, When equipped with a hydraulic top link as a hydraulic actuator that supplies hydraulic oil from the device, and the work implement is mounted via the hydraulic top link, the operator operates the auxiliary operation lever within the reach of the hand. The tip of the piston rod of the hydraulic top link and the connection point such as the top mast on the work machine side can be easily aligned, and after connecting the both, the front and back posture of the work machine can be Adjustment to the posture can be easily performed using the auxiliary operation lever. Therefore, when adjusting the position of the connection point and adjusting the front / rear posture of the work implement as described above, it is not necessary for the operator to repeatedly move up and down to the control section and operate the external hydraulic operation lever, which greatly improves workability.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of a crawler tractor 1 that is a work vehicle, and FIG. 2 is also a rear view. The crawler tractor 1 has an engine 3 mounted on a body frame 2 in the same manner as a normal agricultural tractor. A bonnet 4 and a cabin 5 are provided. In the cabin 5, a seat 6 (see FIG. 4) on which an operator is seated and a control unit 7 on which various operation levers and switches are arranged are provided. Yes.

  A three-point link type work machine lifting mechanism 8 on which a work machine for performing various operations is mounted is always installed in the lower rear portion of the cabin 5. 9L and 9R are a pair of left and right crawler type traveling devices, and the body frame 2 is supported on the crawler type traveling devices 9L and 9R.

  FIG. 3 is a hydraulic circuit diagram of the crawler tractor 1. The pair of left and right lift cylinders 10, 10 provided in the work implement lifting mechanism 8 is fixed at the lower end of the cylinder tube 10 a to the rear wall 11 of the fuselage. The upper and lower ends of the piston rod 10b are connected to the lift arms 13 and 13, respectively, while being pivotally supported by the provided left and right stays 12 and 12, respectively. More specifically, a lift arm bracket 14 is provided horizontally on the upper portions of the stays 12 and 12, and a pair of left and right lift arms 13 and 13 are vertically moved at both ends of a support shaft 15 inserted through the lift arm bracket 14. The piston rod 10b of the lift cylinder 10 is connected to a substantially intermediate portion between the lift arms 13 and 13 while being integrally connected so as to be swingable.

  A pair of left and right lower links 16 and 16 are pivotally supported at the lower part of the pair of left and right stays 12 and 12, respectively, and a substantially intermediate portion of both lower links 16 and 16 and the lift arms 13 and 13 are lifted (not shown). It is connected via a rod. Note that a lift rod cylinder (double-acting hydraulic cylinder) 17 (see FIG. 3) is provided on either the left or right lift rod. Regardless of this, it is possible to execute rolling control that keeps the right and left inclination of the work implement constant.

  Furthermore, a support portion 18 that pivotally supports a top link (not shown) is provided at the center lower portion of the lift arm bracket 14, and a three-point link mechanism constituted by the top link and a pair of left and right lower links 16, 16; Work that can be moved up and down by a pair of left and right lift arms 13, 13 that suspends the three-point link mechanism via a lift rod, and lift cylinders 10, 10 that forcibly swing the lift arms 13, 13 up and down. A machine lifting mechanism 8 is configured.

  Next, the hydraulic circuit of the crawler tractor 1 will be described with reference to FIG. 3. The hydraulic circuit is driven by a hydraulic oil tank T that stores hydraulic oil and an engine 3 that pumps hydraulic oil in the hydraulic oil tank T. Working machine hydraulic pump 19, working machine hydraulic device 20 for working machine lifting mechanism 8 equipped in the machine body, and work such as wing harrow, big baler, plow and the like having a hydraulic operation unit that operates via a hydraulic actuator In order to supply hydraulic oil to the machine, an external hydraulic pressure take-out device (auxiliary control valve unit) 21 comprising a multi-directional control valve is provided, and this external hydraulic pressure take-out device 21 is provided at the rear lower part (rear part of the fuselage) of the cabin 5. It is arranged.

  The working machine hydraulic pump 19 and the work machine hydraulic device 20 are connected via the center bypass oil passage 22 of the multiple directional control valves 21a and 21b constituting the external hydraulic pressure take-out device 21. The operation of the lift cylinders 10 and 10 and the lift rod cylinder 17 is controlled by the device 20, and a work implement lowering speed adjustment valve 23 for adjusting the reduction operation speed of the lift cylinders 10 and 10 is provided.

  The work machine hydraulic device 20 includes a diversion valve 20a for diverting hydraulic oil supplied from the work machine hydraulic pump 19, a lift arm control valve 20b connected to one diversion oil path, and the other diversion oil path. A lift rod control valve 20c connected to the cylinder is inserted, and is configured as one assembly.

  Also, as shown in FIG. 4, external hydraulic operation levers 24a and 24b are provided on one side of the seat 6 in the cabin, and wires 25a and 25b and swing arms 26a linked to the external hydraulic operation levers 24a and 24b. The valve spools 27a and 27b included in the multi-directional control valves 21a and 21b corresponding to the external hydraulic operation levers 24a and 24b are configured to be able to enter / exit (slide) via 26b and the like.

  The hydraulic hoses 32a and 32b are connected via the quick couplers 28 and 28 that can be connected to the hydraulic oil take-out ports and the return ports of the multiple directional control valves 21a and 21b, and the other ends of the hydraulic hoses 32a and 32b. Is connected to a desired hydraulic actuator, so that the hydraulic operating part provided in the work implement, for example, the rake drive device provided in the wing harrow, the left and right wing folding devices, etc. can be adapted to the operating direction of the external hydraulic control levers 24a and 24b. And can be operated in a desired direction.

  By the way, the rear lower part (rear part of the machine body) of the cabin 5 is provided with the three-point link mechanism for mounting the work implement as described above, and a turnbuckle top is used as a top link constituting the three-point link mechanism. In recent years, a hydraulic top link (hydraulic actuator) 31 (see FIG. 3) is used instead of the turnbuckle top link in order to facilitate the mounting and adjustment work of the work machine. It has been widely adopted.

  As shown in FIGS. 3 and 4, the cylinder port of the hydraulic top link 31 is connected to the pressure port P1 and the return port T1 of the multiple directional control valve 21a constituting the external hydraulic pressure take-out device 21 with a hydraulic hose 32a. , 32b, and the piston rod of the top link 31 can be expanded and contracted in a desired direction via the external hydraulic operation lever 24a in the cabin 5.

  However, in this case, when the tip of the piston rod of the hydraulic top link 31 is connected to the top mast or the like of the counterpart work machine, first the fixed work machine and the left and right lower links 16 and 16 are connected, The operator must extend or contract the piston rod while operating the external hydraulic control lever 24a in the cabin 5 to align the tip of the piston rod with a connection point such as a top mast of the work machine. At this time, the operator is forced to move up and down repeatedly to the cabin 5 in order to operate the external hydraulic operation lever 24a.

  And after connecting the front-end | tip mast of the said piston rod, the top mast, etc. of a working machine using a connecting pin, in order to adjust the front-back attitude | position of a working machine to a predetermined working posture, left and right via lift cylinders 10 and 10 are used. In a state where the lower links 16 and 16 are moved up and the work implement is pulled away from the ground, it is necessary to operate the external hydraulic operation lever 24a again to extend or contract the piston rod. In order to operate the hydraulic operation lever 24a, it has to be repeatedly raised and lowered to the cabin 5, and the crawler tractor 1 is a large work vehicle.

  Therefore, in the present invention, in order to solve the above-described problem, as shown in FIGS. 5 and 6, conventional swing arms 26a and 26b connected to the valve spools 27a and 27b of the multiple direction control valves 21a and 21b are provided. By extending toward the rear of the machine body, the valve spools 27a, 27b can be directly operated from the outside of the machine in a state of being directly connected to the valve spools 27a, 27b, thereby providing auxiliary operation levers 33a, 33b. When the work implement is mounted via a hydraulic top link 31 that supplies hydraulic oil from the external hydraulic pressure take-out device 21 provided in the vicinity of the external hydraulic pressure take-out device 21, the operator can move the auxiliary operation lever within the reach of the hand. 33a can be operated to easily align the tip of the piston rod of the hydraulic top link 31 and the connection point such as the top mast on the work machine side. Cormorant with will, by adjusting the longitudinal position of the working machine after connecting both to a predetermined working posture will allow easy to operate the auxiliary control lever 33a. Therefore, when adjusting the position of the connection point and adjusting the front / rear posture of the work implement as described above, it is not necessary for the operator to repeatedly move up and down to the control section 7 and operate the external hydraulic operation lever 24a, thereby greatly improving workability. To do.

  Further, a plurality of work lights 34,... Used for night work are attached to the outer frame of the cabin 5 on the front front side of the windshield (not shown) of the control unit 7 of the crawler tractor 1. However, the light of this work lamp may be reflected on the upper surface of the bonnet 4 and the operator may feel dazzling. As a countermeasure, the bonnet 4 that is generally gloss-coated is shown on the upper surface (indicated by hatching in FIG. 1). The reflected light of the work lamp may be reduced by applying a matte coating only to (part).

  In addition, left and right side mirrors 35L and 35R are attached to a column (not shown) on the front side of the cabin 5 as shown in FIGS. As shown in FIGS. 7A and 7B, the side mirrors 35L and 35R are attached via a plate-like base 37 that can be screwed to a bracket 36 fixed to the support column. The base end of a rod-like arm 38 bent and formed in a substantially inverted U shape is fitted to a boss 37a fixed to the tip of the base 37 so as to be rotatably supported, and at the tip of the rod-like arm 38. The side mirrors 35L and 35R are configured to be screwed.

  The above-described base 37 is provided with a long hole 37b in which the base 37 can be slidably adjusted in the left-right direction as indicated by arrows B and C shown in the figure. First, the side mirror 35R (35L) is pulled out from the normal use position D in the E arrow direction (outward direction) to the F position, and then the rod arm 38 is moved from the F position to the G arrow direction (airframe rear direction). When the base end portion is turned to the H position with the fulcrum as a fulcrum, the operator can check the outer end J of the crawler 9a with the side mirror 35R (35L) in a normal driving posture, so Etc. can be easily performed.

  When the body is stored in a garage or the like, if the side mirror 35R (35L) is returned to the normal use position D, a collision between the side mirror 35R (35L) and a nearby object can be avoided. Further, in FIG. 9, a turnbuckle 39 is interposed in the middle of the straight portion of the upper part of the bar-shaped arm 38 bent in a substantially inverted U shape, and the side mirror 35L, The 35R can be adjusted to slide in the left-right direction of the aircraft.

The partially broken top view of a crawler tractor. The back view of a crawler tractor. The hydraulic circuit diagram of a crawler tractor. The perspective view which shows the structure of the conventional external hydraulic control lever. Part A (external hydraulic pressure takeout device) details in FIG. Part B (external hydraulic pressure takeout device) details in FIG. (A), (b) The schematic rear view which shows the left-right slide adjustment method of a side mirror. The schematic plan view which shows the position adjustment method of a side mirror. The schematic rear view which shows the other example of the left-right slide adjustment method of a side mirror.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Work vehicle 7 Control part 21 External hydraulic take-out apparatus 21a Direction control valve 24a External hydraulic operation lever 33a Auxiliary operation lever

Claims (1)

  In a work vehicle (1) provided with an external hydraulic operation lever (24a) for operating a direction control valve (21a) of an external hydraulic pressure take-out device (21) disposed in a machine body in a control section (7), the direction control valve (21a ) Is provided with an auxiliary operation lever (33a) that can be directly operated from outside the machine.

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