JP2006160492A - Self-propelled work machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase work efficiency in assembling and maintenance while efficiently performing installation operations for control valves and hydraulic pipes on the frame of a vehicle body. <P>SOLUTION: The frame 3 of the vehicle body comprises a pair of left vertical plate 4 and a right vertical plate 5 laterally apart from each other and extending in the forward and rearward directions and a bottom plate 6 connecting the left vertical plate 4 to the right vertical plate 5 in the lateral direction. Also, a control valve/pipe assembly 41 is formed by installing, for example, a preference valve 47 for steering and an unloading valve 51 among a plurality of control valves installed in a work machine on a single mounting plate 42 together with a plurality of hydraulic pipes beforehand. Then, the preliminarily assembled control valve/pipe assembly 41 is formed to be mountable on and dismountable from the right vertical plate 5 of the frame 3 with a plurality of bolts by using the mounting plate 42 at the lower position of the bottom plate 6. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a self-propelled working machine suitably used for, for example, a lift truck, a forklift, a wheel loader or the like that performs a cargo handling operation.

  In general, a self-propelled working machine such as a lift truck can be raised and lowered on the frame of a self-propelled vehicle body and the rear side of the frame, for example, in order to carry a load (load handling work) from the ground to a high place. And a telescopic working device that is extended and contracted by a plurality of hydraulic actuators (see, for example, Patent Documents 1 and 2).

  Then, pressure oil is supplied to the frame of the vehicle body from the front and rear wheels and a hydraulic source, which are driven to travel via a driving force transmission shaft such as a propeller shaft extending in the forward and rearward directions on the lower side of the frame. A traveling hydraulic actuator that rotates and drives the driving force transmission shaft by being discharged, a steering hydraulic actuator that steers the wheel by pressure oil from the hydraulic source, and the like are provided. Between the hydraulic actuator for traveling and steering and the hydraulic pressure source, a plurality of control valves for controlling the operation, stop and the like of each hydraulic actuator are provided via hydraulic pipings or the like.

Japanese Patent No. 2559831 JP-A-8-118966

  By the way, in the above-described self-propelled working machine according to the prior art, for example, a driving force transmission shaft such as a propeller shaft extends forward and backward on the lower side of the frame, and a telescopic working device can be raised and lowered on the upper side of the frame. Is provided. A plurality of control valves for controlling the operation, stop, etc. of each hydraulic actuator, and a plurality of hydraulic pipes connected to these control valves are moved upward and downward by the working device and the driving force transmission shaft. It is arranged in a limited frame space.

  For this reason, in the prior art, a great amount of labor and time is spent on the work of mounting the plurality of control valves and the hydraulic piping in a limited space in the frame, and the workability during assembly is very poor. There is a problem.

  In addition, when performing maintenance and inspection of the control valves, hydraulic piping, etc., it is necessary to perform maintenance work in a frame space restricted in the upward and downward directions by the driving force transmission shaft and the working device. There is a problem that the burden on the maintenance worker cannot be reduced.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to efficiently perform assembly work of a control valve, hydraulic piping, and the like to a vehicle body frame. An object of the present invention is to provide a self-propelled working machine that can improve the workability of the machine.

  In order to solve the above-described problem, the invention of claim 1 is directed to a vehicle body frame, and a front side of the frame, which is rotatably provided on the lower side of the frame, and a driving force transmission shaft extending in the rearward direction. A rear wheel, a hydraulic actuator for driving to rotate the driving force transmission shaft by supplying and discharging pressure oil from a hydraulic source, and a steering for steering the wheel by pressure oil from the hydraulic source A hydraulic actuator, a working device provided on the upper side of the frame and driven by a working hydraulic actuator, and a plurality of hydraulic pipes provided between the hydraulic source and each hydraulic actuator, respectively. The present invention is applied to a self-propelled work machine including a plurality of control valves that control operation.

  A feature of the configuration adopted by the invention of claim 1 is that a control valve / pipe assembly is constructed by assembling at least a part of the plurality of control valves together with a plurality of hydraulic pipes into a single bracket. The control valve / pipe assembly is detachably attached to the position in the frame above the driving force transmission shaft and below the work device using the bracket.

  According to a second aspect of the present invention, the frame includes a pair of vertical plates that are spaced apart left and right and extend in the front and rear directions, and a bottom plate that connects the pair of vertical plates in the left and right directions. The control valve / pipe assembly is attached to one of the pair of vertical plates.

  According to a third aspect of the present invention, the some control valves drive the hydraulic pressure source and the steering priority valve that supplies the hydraulic oil from the hydraulic source with priority to the hydraulic actuator for steering. It is composed of an unload valve that is switched and controlled to reduce the load on the prime mover.

  On the other hand, according to the invention of claim 4, the bracket of the control valve / piping assembly includes a horizontal plate portion assembled in a state where one of the plurality of control valves is disposed horizontally, and the horizontal plate And a vertical plate portion to which another control valve is assembled. The horizontal plate portion is disposed at a position above the driving force transmission shaft and below the working device. The vertical plate portion is arranged below the working device and on the left and right sides of the driving force transmission shaft.

  According to a fifth aspect of the present invention, the horizontal plate portion of the bracket is provided with a notch for securing a gap between the horizontal plate portion and the control valve assembled to the vertical plate portion.

  According to the invention of claim 6, the bracket is provided with a pipe insertion hole for a hydraulic pipe connected between the control valves.

  Further, according to the invention of claim 7, the bracket is provided with a screw seat for fixing a hydraulic pipe different from the hydraulic pipe connected between the control valves.

  As described above, the invention according to claim 1 constitutes a control valve / pipe assembly by assembling at least a part of the plurality of control valves together with a plurality of hydraulic pipes into a single bracket. The control valve can be pre-assembled compactly through the bracket together with hydraulic piping or the like. And in the frame of the vehicle body, the control valve / pipe assembly can be assembled into a space limited in the upper and lower directions by the upper working device and the lower driving force transmission shaft. It is possible to improve workability during assembly and maintenance.

  That is, the control valve / piping assembly is configured to be detachably attached using the bracket at a position in the frame that is above the driving force transmission shaft and below the work device. By simply attaching the bracket of the piping assembly to the frame of the vehicle body, the operation of assembling the control valve to the frame together with the hydraulic piping can be performed efficiently, and the assembly workability of the self-propelled working machine can be improved. .

  In the invention according to claim 2, the frame is constituted by a pair of vertical plates and a bottom plate, and the control valve / pipe assembly is attached to one of the pair of vertical plates. For example, the control valve / pipe assembly bracket can be attached to the inner surface of the vertical plate by fastening it with bolts from the lateral direction (left, right), improving workability during assembly and maintenance. Can do.

  According to a third aspect of the present invention, there is provided a steering priority valve that preferentially supplies pressure oil from a hydraulic power source to a steering hydraulic actuator, and an unload valve that is switch-controlled to reduce the load on the prime mover. And the hydraulic piping connected to the steering priority valve and the unloading valve in a single bracket, the control valve / pipe assembly can be pre-assembled outside the vehicle body. Workability at the time can be improved.

  On the other hand, according to the invention described in claim 4, since the bracket of the control valve / pipe assembly has a horizontal plate portion and a vertical plate portion, the horizontal plate portion has one of a plurality of control valves. One control valve can be assembled in a horizontally arranged state, and another control valve can be assembled to the vertical plate portion. When the control valve / piping assembly is attached to the frame of the vehicle body, the horizontal plate portion of the bracket can be disposed at a position above the driving force transmission shaft and below the working device, and the vertical plate portion is The driving force transmission shaft can be disposed on the left side and the right side (left side or right side) of the driving force transmission shaft below the working device. In addition, even if flying objects such as stepping stones are generated around the driving force transmission shaft, the collision of the flying objects against the control valve or the like can be prevented by the horizontal plate portion of the bracket, and these durability and life are improved. be able to.

  According to the invention described in claim 5, since the horizontal plate portion of the bracket is provided with a notch for securing a gap with the control valve assembled to the vertical plate portion, It is possible to prevent the control valve on the side of the vertical plate portion from contacting and interfering with the horizontal plate portion by the notch, and it is possible to improve durability, life, etc. of the control valve against vibration.

  In the invention according to claim 6, since the pipe insertion hole for the hydraulic pipe connected between the control valves is provided in the bracket of the control valve / pipe assembly, the control is provided in the pipe insertion hole. Piping work can be easily performed by inserting hydraulic piping connecting the valves, and such hydraulic piping can be compactly assembled to the bracket of the control valve / piping assembly.

  Furthermore, according to the invention described in claim 7, the bracket is provided with a screw seat for fixing a hydraulic pipe different from the hydraulic pipe connected between the control valves. It is possible to arrange hydraulic piping around the bracket in a compact manner.

  Hereinafter, a case where a self-propelled working machine according to an embodiment of the present invention is applied to a lift truck will be described as an example and described in detail with reference to the accompanying drawings.

  Here, FIG. 1 to FIG. 18 show a first embodiment of the present invention. In the figure, reference numeral 1 denotes a lift truck as a self-propelled working machine, and the lift truck 1 is composed of a wheel-type vehicle body 2 capable of self-propelling, a working device 24 described later, and the like. The lift truck 1 performs, for example, a cargo handling operation for transporting cargo from the ground to a high place using the work device 24 after self-propelled to the work site.

  Reference numeral 3 denotes a frame serving as a base of the vehicle body 2. The frame 3 is formed by using a thick steel plate or the like as shown in FIGS. The vertical plates 4 and 5 (the left vertical plate 4 and the right vertical plate 5) are formed using a thick steel plate or the like in the same manner as the vertical plates 4 and 5, and the space between the vertical plates 4 and 5 is left and right. It is comprised by the bottom plate 6 connected (joined) by, and the below-mentioned reinforcement board 7 grade | etc.,.

  A front wheel support 6A for supporting each front wheel 13 described later is provided on the front side of the bottom plate 6, and a rear wheel support 6B for supporting each rear wheel 15 described below is provided on the rear side of the bottom plate 6. Is provided. Further, as shown in FIGS. 4, 9, and 10, the bottom plate 6 is provided with an oval notch hole 6C, a small-diameter pipe insertion hole 6D, and the like at a position on the front side of the rear wheel support portion 6B. The notch hole 6C and the pipe insertion hole 6D are disposed at a position above the control valve / pipe assembly 41 described later.

  7 is a reinforcing plate welded between the right vertical plate 5 and the bottom plate 6 of the frame 3. The reinforcing plate 7 is formed by bending a steel plate, for example, as shown in FIGS. It is formed by. The reinforcing plate 7 increases the strength of the right vertical plate 5 around the hydraulic pump 36, which will be described later, and also increases the bonding strength of the right vertical plate 5 with respect to the bottom plate 6, etc. The right vertical plate 5 side can be supported with high strength.

  Reference numeral 8 denotes a stabilizer mounting portion provided on the front end side of the frame 3, and a stabilizer 31 (to be described later) is pin-coupled to the stabilizer mounting portion 8 so as to extend leftward and rightward as shown in FIGS. Is. The left vertical plate 4 of the frame 3 is provided with a cylinder mounting portion 9 at a position corresponding to the front wheel support portion 6A between the stabilizer mounting portion 8 and a device support portion 11 described later. Is a pin connection of an inclination correction cylinder 34 described later.

  Reference numerals 10 and 10 denote cab support portions provided on the left vertical plate 4 of the frame 3. The cab support portions 10 and 10 are intermediate portions in the front and rear directions of the left vertical plate 4 as shown in FIGS. Projects from the outside to the left (outward). Each cab support portion 10 supports a cab 22 described later via the left vertical plate 4 of the frame 3 together with a support seat 10 </ b> A provided on the inner side surface of the left vertical plate 4.

  Reference numeral 11 denotes a device support portion provided at an intermediate portion in the front and rear direction of the right vertical plate 5, and the device support portion 11 projects rightward from the right vertical plate 5 as shown in FIG. 4, for example, an engine as a prime mover. 12, the below-described hydraulic pumps 36 and 37, a heat exchange device such as a radiator, and other devices (both not shown) are supported from the lower side. On the device support 11, a device cover 11 </ b> A and the like are provided as shown in FIG. 2, and the device cover 11 </ b> A is opened and closed during maintenance (maintenance and inspection) of the engine 12 and the like.

  Reference numerals 13 and 13 denote left and right front wheels rotatably provided on the front portion side of the frame 3 via an axle housing 14 and the like. The left and right front wheels 13 and 13 are axle housings as shown in FIG. 14 is attached to both the left and right ends of 14 so as to be rotatable and steerable via an axle or the like.

  The left and right front wheels 13 are configured to travel and drive the vehicle body 2 together with the rear wheels 15 described later when a rotational driving force by a travel actuator 17 described later is transmitted from the propeller shaft 18 via an axle or the like. . The left and right front wheels 13 are steered via a steering cylinder 20 and the like by a steering handle 62A (see FIG. 17) disposed in a cab 22 described later. In the lift truck of the present embodiment, the 2WS mode in which only the left and right front wheels 13 are steered, the 4WS mode in which the rear wheels 15 are steered in the opposite direction together with the steering of the front wheels 13, and the rear with the steering of the front wheels 13. A club mode in which the wheels 15 are steered in the same direction is provided, and the steering system can be changed by switching a steering switching valve 65 described later.

  Here, the axle housing 14 is swingably attached to the bottom plate 6 of the frame 3 on the lower surface of the front wheel support portion 6A via a support pin (not shown). The axle housing 14 has a function of correcting, together with an inclination correction cylinder 34 described later, that the frame 3 of the lift truck 1 is inclined upward and downward in the left and right directions.

  Reference numeral 15 denotes a left and right rear wheel rotatably provided on the rear side of the frame 3 via an axle housing 16 and the like. These left and right rear wheels 15 are also connected to the left and right ends of the axle housing 16 on the left and right ends. The axle housing 16 in this case is also rotatably supported by the rear wheel support portion 6B of the bottom plate 6 via a support pin (not shown) or the like.

  The left and right rear wheels 15 are driven to drive the vehicle body 2 together with the front wheels 13 by receiving a rotational driving force from a propeller shaft 19 via an axle or the like, as will be described later. The left and right rear wheels 15 are steered with the front wheels 13 by a steering handle 62A, which will be described later, and controls the traveling direction of the vehicle body 2.

  Reference numeral 17 denotes a traveling hydraulic actuator (hereinafter referred to as a traveling actuator 17) provided on the frame 3 below the bottom plate 6. The traveling actuator 17 is, for example, a traveling hydraulic motor and a speed controlled hydraulically. It is configured to include machines. The traveling actuator 17 rotates and drives propeller shafts 18 and 19 to be described later when pressure oil is supplied and discharged from a hydraulic source.

  Reference numerals 18 and 19 denote propeller shafts as driving force transmission shafts extending forward and rearward from the travel actuator 17, and the propeller shafts 18 and 19 are connected to the front and rear axle housings 14 and 16 as shown in FIGS. It is arranged between the traveling actuator 17 and transmits the rotational driving force by the traveling actuator 17 to the front wheels 13 and the rear wheels 15.

  Reference numeral 20 denotes a front-wheel steering cylinder constituting a hydraulic actuator for steering that steers the left and right front wheels 13, 13. The steering cylinder 20 is provided below the front wheel support portion 6A as shown in FIGS. Located and attached to the axle housing 14. As shown in FIG. 17, the steering cylinder 20 steers the front wheels 13 by supplying and discharging pressure oil from a later-described hydraulic pump 36 via a steering priority valve 47, a steering operation valve 62, and the like. Is.

  Reference numeral 21 denotes a rear-wheel-side steering cylinder constituting a hydraulic actuator for steering that steers the left and right rear wheels 15 and 15. The steering cylinder 21 includes a rear wheel support portion 6B as shown in FIGS. Located on the lower side and attached to the axle housing 16. As shown in FIG. 17, the steering cylinder 21 steers the rear wheel 15 by supplying and discharging pressure oil from the hydraulic pump 36 via the steering priority valve 47, the steering operation valve 62, and the like. It is.

  Reference numeral 22 denotes a cab that constitutes an operation operation unit of the lift truck 1. The cab 22 is connected to the left vertical plate 4 of the frame 3 shown in FIGS. 3 and 4 through the cab support 10 and the support seat 10A. It is mounted as shown in FIG. 2 and defines a cab inside. The cab 22 is provided with a driver's seat 23 (described later) on which an operator is seated, a steering handle 62A, an accelerator pedal, a plurality of operation levers (none of which are shown), and the like.

  Reference numeral 23 denotes a driver seat provided in the cab 22, which is attached to the left vertical plate 4 of the frame 3 via a floor plate (not shown) of the cab 22 as shown in FIG. 2. is there. An operator getting on and off the cab 22 operates the steering handle 62A (see FIG. 17), the accelerator pedal, the operation lever, and the like while seated in the driver's seat 23, for example.

  24 is a work device for cargo handling work provided on the rear side of the vehicle body 2 so as to be able to move up and down. The work device 24 has a frame 3 (vertical plates 4 and 5) on the base end side as shown in FIGS. The boom 25 is connected to the upper end of the rear part so as to be able to move up and down, and extends in the front and rear directions, and a fork 26 as a loading / unloading work tool attached to the front end side of the boom 25 so as to be able to rotate upward and downward. It is configured. The working device 24 is disposed on the upper side of the frame 3, and the boom 25 of the working device 24 is configured by, for example, a three-stage (multiple-stage) telescopic boom.

  Further, a boom hoisting cylinder 27 indicated by a dotted line in FIG. 1 is provided between the frame 3 and the boom 25. The boom hoisting cylinder 27 is supplied from hydraulic pumps 36 and 37, which will be described later, via a direction control valve 39A. When the pressure oil is supplied and discharged, the boom 25 shown in FIGS. 1 and 2 moves up and down.

  Reference numeral 28 denotes a boom telescopic cylinder provided in the work device 24. The boom telescopic cylinder 28 is provided outside the boom 25 as shown in FIG. 1, and extends and retracts the telescopic boom 25 described above in the length direction. Is. A fork cylinder 29 as a working tool cylinder is provided between the tip of the boom 25 and the fork 26. The fork cylinder 29 rotates the fork 26 up and down on the tip side of the boom 25. To do.

  Here, the boom hoisting cylinder 27, the boom telescopic cylinder 28, the fork cylinder 29, and the like constitute a working hydraulic actuator that operates the working device 24. These cylinders 27, 28, and 29 are expanded and contracted by supplying and discharging pressure oil from the hydraulic pump 36 and the like via directional control valves 39A, 39B, and 39C described later shown in FIG. .

  Reference numeral 30 denotes a vehicle body stabilization device provided on the front side of the vehicle body 2. The vehicle body stabilization device 30 is a left and right stabilizer mounted on the stabilizer mounting portion 8 of the frame 3 as shown in FIGS. 31 and 31 and an inclination correction cylinder 34 described later. Further, the left and right stabilizers 31, 31 have stabilizer cylinders 32, 32.

  The stabilizer 31 extends in the left and right directions from the stabilizer mounting portion 8 by extending the stabilizer cylinder 32 as shown in FIGS. 1 and 2 at the time of cargo handling work using the working device 24, and the like. To the ground. Further, when the stabilizer cylinder 32 is contracted, the ground plate 33 of the stabilizer 31 is greatly raised upward from the ground to prevent the stabilizer 31 from becoming an obstacle when the vehicle is traveling.

  Reference numeral 34 denotes an inclination correction cylinder attached to the right vertical plate 5 of the frame 3 through a cylinder attachment portion 9. The inclination correction cylinder 34 abuts on the axle housing 14 on the front wheel 13 side so as to extend and contract as shown in FIG. The inclination correction (frame leveling) in the left and right directions of the frame 3 is performed.

  That is, when the lift truck 1 stops on an inclined ground (for example, an inclined ground where the vehicle tilts left and right), the frame 3 of the vehicle body 2 tilts left and right together with the axle housing 14 and the like on the front wheel 13 side. There is. However, in this case, the axle housing 14 is attached to the front wheel support portion 6A of the bottom plate 6 so as to be swingable in the left and right directions via the support pins and the like.

  For this reason, if the tilt correction cylinder 34 is appropriately expanded and contracted between the frame 3 and the axle housing 14, the frame 3 (bottom plate 6) side of the vehicle body 2 is positioned with respect to the axle housing 14 tilted by the slope. It can be swung so as to be relatively inclined in the left and right directions, whereby the inclination of the vehicle body 2 can be corrected.

  Thus, the vehicle body stabilization device 30 makes the grounding plate 33 contact the ground with the stabilizer 31 extended to the left and right using the stabilizer cylinder 32 during cargo handling work (when the vehicle is stopped) and the like. The correction cylinder 34 is used to correct the inclination of the vehicle body 2 and thereby prevent the vehicle body 2 from falling.

  A fuel tank 35 is provided on the rear side of the frame 3 as shown in FIG. 2, and the fuel tank 35 is attached to the rear side of the right vertical plate 5 constituting a part of the frame 3 from the side. . The fuel tank 35 is formed as a hollow container having a substantially rectangular shape made of, for example, a high-strength synthetic resin material, and supplies fuel to the engine 12 in the equipment cover 11A.

  Reference numeral 36 denotes a main hydraulic pump that is rotationally driven by the engine 12, and the hydraulic pump 36, together with a hydraulic oil tank 38, which will be described later, constitutes a hydraulic source, and as shown in FIGS. Pressure oil is supplied to and discharged from the hoisting cylinder 27, the boom telescopic cylinder 28, the fork cylinder 29, the stabilizer cylinder 32, the inclination correction cylinder 34, and the like.

  The hydraulic pump 36 protrudes from the device support 11 side to the inner side of the frame 3 (left side of the right vertical plate 5) while being attached to the engine 12, as shown in FIGS. Although it does not reach the left vertical plate 4, it extends to a position beyond the propeller shaft 19. That is, the hydraulic pump 36 is disposed between the left and right vertical plates 4 and 5 in the frame 3.

  Reference numeral 37 denotes a sub hydraulic pump. The sub hydraulic pump 37 is configured as a smaller pump than the main hydraulic pump 36 as illustrated in FIG. is there. The sub hydraulic pump 37 is also driven by the engine 12 and constitutes a part of the hydraulic power source. The sub hydraulic pump 37 joins with the main hydraulic pump 36 in the middle of a supply pipe 50 described later as shown in FIG.

  3 and 4, a hydraulic oil tank (hereinafter referred to as a tank 38) provided on the outside of the left vertical plate 4, as shown in FIGS. 3 and 4, is disposed below the cab 22, for example. A hydraulic power source is configured together with the pumps 36, 37 and the like.

  39 is a control valve device for work provided on the inner side surface of the left vertical plate 4. The control valve device 39 is arranged inside the left vertical plate 4 where the tank 38 is installed as shown in FIG. It is detachably attached to the opposite surface. The working control valve device 39 is formed as a control valve block in which a plurality of control valves for controlling each working hydraulic actuator are overlapped on the top and bottom, and the control valve in this case is shown in FIG. As illustrated, a total of four directional control valves 39A, 39B, 39C, and 39D are configured.

  Here, the working control valve device 39 connects the directional control valves 39A to 39D using a parallel circuit as shown in FIG. 18, and the center bypass pipe 39E includes the hydraulic pumps 36, 37 is connected via a supply pipe 50 and the like which will be described later. The direction control valve 39A of the control valve device 39 supplies or discharges, for example, pressure oil from the hydraulic pump 36 to the boom hoisting cylinder 27 of the work device 24, and controls the operation (extension / contraction) of the boom hoisting cylinder 27. .

  Further, the direction control valve 39B of the control valve device 39 supplies and discharges, for example, pressure oil from the hydraulic pump 36 to the boom telescopic cylinder 28, and causes the boom 25 to extend and contract in the length direction by the boom telescopic cylinder 28. Further, the directional control valve 39C of the control valve device 39 supplies or discharges the pressure oil from the hydraulic pump 36 to the fork cylinder 29, for example, and rotates the fork 26 shown in FIG. Is.

  The direction control valve 39D of the control valve device 39 supplies and discharges pressure oil to a spare hydraulic cylinder 67, which will be described later. And each operation lever (not shown) which performs switching operation of these direction control valves 39A-39D is arranged so as to protrude from the left vertical plate 4 side into the cab 22 shown in FIGS. It is manually tilted by an operator who has entered the cab 22.

  Reference numeral 40 denotes a control valve device for stabilizing the vehicle body provided on the inner side surface of the left vertical plate 4 in front of the control valve device 39 for work. The control valve device 40 is a vehicle body stabilization shown in FIG. A plurality of control valves for controlling the device 30 are formed as a control valve block formed by overlapping the upper and lower sides, and the control valves in this case include a total of three directional control valves 40A, 40B, 40C.

  Here, the control valve device 40 for stabilizing the vehicle body connects the direction control valves 40A to 40C using a parallel circuit as shown in FIG. 18, and the center bypass conduit 40D is a control valve device for work. It is connected to 39 center bypass conduits 39E. Then, the direction control valves 40A and 40B of the control valve device 40 supply and discharge, for example, pressure oil from the hydraulic pump 36 to the left and right stabilizer cylinders 32 and 32, and actuate (expand / contract) each stabilizer cylinder 32. It is something to control.

  In addition, the direction control valve 40C of the control valve device 40 supplies and discharges, for example, pressure oil from the hydraulic pump 36 to the inclination correction cylinder 34, and expands and contracts the inclination correction cylinder 34 up and down. The tilt correction cylinder 34 corrects the tilt of the vehicle body 2 shown in FIG. 2 to stabilize the posture of the vehicle body 2 on, for example, an inclined ground.

  The control valve device 40 for stabilizing the vehicle body and the control valve device 39 for working are attached to the left vertical plate 4 so as to be separated from each other in the front and rear directions as shown in FIG. Is disposed at a position close to the rear side of the work device 24 (the base end side of the boom 25). Further, the control valve device 40 for stabilizing the vehicle body located in front of the control valve device 39 is disposed at a position close to the vehicle body stabilization device 30 (stabilizer mounting portion 8 and cylinder mounting portion 9) shown in FIG. .

  Reference numeral 41 denotes a control valve / pipe assembly employed in the present embodiment. The control valve / pipe assembly 41 includes a mounting plate 42, a steering priority valve 47, a discharge pipe, which will be described later, as shown in FIGS. 48, 52, supply pipe 50, unload valve 51, merging pipe 53, return pipe 54, pilot pipe 55, relief valve 56, relief pipes 57, 58, drain pipes 59, 60, 61, and the like.

  As shown in FIGS. 11 and 15, the control valve / pipe assembly 41 includes a steering priority valve 47, an unload valve 51, and a relief valve 56, and a plurality of pipes 48, 50, 52, 53, 54, 55, Attached to the mounting plate 42 together with 57, 59 and the like in advance, the mounting plate 42 is used to detachably attach to the right vertical plate 5 of the frame 3 from below the bottom plate 6.

  Reference numeral 42 denotes a mounting plate constituting a bracket of the control valve / pipe assembly 41. The mounting plate 42 is composed of, for example, two steel plates composed of a horizontal plate portion 43 and a vertical plate portion 44 as shown in FIGS. By joining each other by welding means or the like, a bracket having an L shape as a whole is formed. The horizontal plate portion 43 is formed by bending a flat steel plate into a U-shape as shown in FIGS. 12 and 13, and the mounting plate portion 43A and the front and rear side plate portions 43B and 43C are formed. Have.

  The vertical plate portion 44 is disposed perpendicular to the horizontal plate portion 43, and the base end side of the horizontal plate portion 43 is joined to the lower surface side of the vertical plate portion 44. And the horizontal board part 43 is extended in the horizontal direction (left, right direction) from the surface of the vertical board part 44, and the front end side is a free end. Further, the mounting plate portion 43A of the horizontal plate portion 43 is formed with a U-shaped notch 43D located on the base end side, and an unload valve 51 described later is formed in the notch 43D. The lower side is arranged with a gap.

  Here, the vertical plate portion 44 is formed in a flat plate shape extending upward and downward on the notch 43D side of the horizontal plate portion 43, and a first valve mounting portion 44A to which an unload valve 51 described later is mounted; The second valve mounting portion 44B extends obliquely rearward from the first valve mounting portion 44A and is attached with a later-described relief valve 56. The vertical plate portion 44 is fastened to the right vertical plate 5 of the frame 3 by using a plurality of (for example, five) bolts or the like, whereby the entire mounting plate 42 (control valve / pipe assembly 41) is right vertical. The plate 5 is detachably attached.

  In this state, the horizontal plate portion 43 of the mounting plate 42 is arranged at a position above the propeller shaft 19 shown in FIGS. 6 to 8 and at a position below the working device 24 shown in FIG. Established. Further, the vertical plate portion 44 of the mounting plate 42 is disposed at a position below the working device 24 and on the left and right direction one side (the right vertical plate 5 side in FIG. 8) with respect to the propeller shaft 19. Is.

  45 is a pipe insertion hole formed in the side plate portion 43C of the horizontal plate portion 43. The pipe insertion hole 45 is formed as a circular hole in the side plate portion 43C at a position close to the vertical plate portion 44 as shown in FIG. A relief pipe 58 described later is inserted as shown in FIG.

  46 is a screw seat provided on the side plate portion 43B of the horizontal plate portion 43, and the screw seat 46 is fixed to the outer side surface (front side surface) of the side plate portion 43B by means of welding or the like as shown in FIG. A return pipe 64, which will be described later, is detachably fixed to the screw seat 46 as shown in FIGS.

  47 is a steering priority valve as a control valve assembled on the mounting plate portion 43A of the horizontal plate portion 43. The steering priority valve 47 is generally called a steering priority valve, and its inflow side is shown in FIG. 17 is connected to the discharge side of the hydraulic pump 36 through a discharge pipe 48 as a hydraulic pipe. Further, the outflow side of the steering priority valve 47 is selectively connected to supply pipes 49 and 50 as hydraulic pipes, and is always arranged at the priority position (a) as shown in FIG.

  The steering priority valve 47 steers pressure oil supplied from the hydraulic pump 36 via the discharge pipe 48 when in the priority position (a) via the supply pipe 49 and a steering operation valve 62 described later. The cylinders 20 and 21 are supplied with priority. Further, the steering priority valve 47 is used for work, vehicle body via the supply pipe 50 or the like for supplying the pressure oil from the hydraulic pump 36 when the priority position (a) shown in FIG. 17 is switched to the switching position (b). It is supplied to the control valve devices 39 and 40 for stabilization.

  Reference numeral 51 denotes an unload valve as a control valve that constitutes a part of the control valve / piping assembly 41. The unload valve 51 includes a vertical plate portion 44 (first plate) of the mounting plate 42 as shown in FIGS. 1 is attached to the valve mounting portion 44A) via a bolt or the like, and the lower side thereof is disposed in the notch 43D of the horizontal plate portion 43 with a gap.

  Here, as shown in FIG. 17, the unload valve 51 has an inflow side connected to a discharge side of a sub hydraulic pump 37 via a discharge pipe 52 as a hydraulic pipe, and an outflow side thereof connected to a merging pipe 53 as a hydraulic pipe. It is selectively connected to the return pipe 54. The unload valve 51 is always arranged at the supply position (c) shown in FIG. 17, and pressure oil supplied from the hydraulic pump 37 via the discharge pipe 52 is supplied via the junction pipe 53, the supply pipe 50, and the like. This is supplied to the control valve devices 39 and 40 for work and vehicle body stabilization.

  The unload valve 51 is connected to a midway position of the merging pipe 53 via a pilot pipe 55 as a hydraulic pipe, and is supplied when the pilot pressure from the pilot pipe 55 rises above the set pressure of the unload valve 51. The position (c) is switched to the return position (d).

  Then, the unload valve 51 switched to the return position (d) causes the hydraulic pump 37 to be in an unload (no load) state by connecting the discharge pipe 52 to the return pipe 54. Thus, the unload valve 51 has a function of reducing the load on the engine 12 (see FIG. 4) that drives the hydraulic pump 37 and preventing the occurrence of engine stall (engine stall) or the like.

  56 is a relief valve as a control valve that constitutes a part of the control valve / pipe assembly 41 together with the unload valve 51. The relief valve 56 is a vertical plate portion of the mounting plate 42 as shown in FIGS. 44 (second valve mounting portion 44B) via a bolt or the like, and is disposed at a position obliquely above the unload valve 51 provided in the first valve mounting portion 44A.

  Here, as shown in FIG. 17, the relief valve 56 is connected between the discharge pipe 52 and the return pipe 54 via relief pipes 57 and 58 as hydraulic pipes. For example, the pressure in the discharge pipe 52 and the junction pipe 53 Is suppressed to a pressure equal to or lower than a predetermined set pressure. The relief valve 56 is opened when the pressure in the discharge pipe 52 exceeds the set pressure, and the excess pressure at this time is relieved to the return pipe 54 via the relief pipes 57 and 58.

  In this case, the inflow side relief pipe 57 is disposed so as to extend from the upper surface side of the unload valve 51 toward the relief valve 56 as shown in FIGS. 11 and 16, and the outflow side relief pipe 58 is provided with a relief. It extends from the lower surface side of the valve 56 toward the pipe insertion hole 45 of the horizontal plate portion 43. The relief pipe 58 is connected to a midway position of the return pipe 54 as shown in FIG. 8 in a state where the relief pipe 58 is inserted into the lower position of the unload valve 51 through the pipe insertion hole 45.

  Reference numerals 59, 60 and 61 denote drain pipes as hydraulic pipes connected to the tank 38. Among the drain pipes 59 to 61, the drain pipe 59 is a spring chamber (not shown) of the unload valve 51 as shown in FIG. ) Side is connected to the tank 38 via a return pipe 64 and the like which will be described later. Further, the drain pipe 60 is connected in the middle of the drain pipe 59 in order to prevent pressure from being accumulated inside the unload valve 51.

  On the other hand, the drain pipe 61 is connected to the spring chamber side of the steering priority valve 47 as shown in FIG. 17, and discharges the pressure oil guided from the steering operation valve 62 described later through the outlet pipe 63 to the tank 38 side. . The drain pipe 61 is connected to a return pipe 64 described later together with other drain pipes 59 and 60 as shown in FIG.

  Reference numeral 62 denotes a steering operation valve for power steering operation of the vehicle. The steering operation valve 62 applies pressure oil corresponding to the steering angle when the operator in the cab 22 manually operates the steering handle 62A. The steering cylinders 20 and 21 are supplied and discharged through a supply pipe 49 and the like, and the steering operation of the front wheels 13 and the rear wheels 15 is performed as a so-called power steering device.

  Here, the steering operation valve 62 is connected to the steering priority valve 47 through a supply pipe 49 as shown in FIG. 17, and a lead-out pipe 63 as a hydraulic pipe is provided between them. The derivation pipe 63 derives a pressure corresponding to the operation amount of the steering operation valve 62 (steering handle 62A) as a differential pressure before and after the steering operation valve 62 with the supply pipe 49.

  Then, the steering priority valve 47 is switched between the priority position (a) and the switching position (b) according to the differential pressure between the supply pipe 49 and the outlet pipe 63. That is, when the steering handle 62A is operated, the differential pressure between the supply pipe 49 and the outlet pipe 63 becomes small, so the steering priority valve 47 is held at the priority position (a), and when the steering operation is released. Since the differential pressure increases, the steering priority valve 47 is switched from the priority position (a) to the switching position (b).

  Reference numeral 64 denotes a return pipe as a hydraulic pipe. The return pipe 64 returns, for example, return oil discharged from the steering cylinders 20 and 21 via the steering operation valve 62 to the tank 38 as shown in FIG. is there. In addition, return oil or the like from the control valve devices 39 and 40 is also returned into the return pipe 64.

  Here, the return pipe 64 is detachably fixed to the screw seat 46 of the mounting plate 42 as shown in FIGS. 8 and 16 and is held in a stable posture in the frame 3. In addition, drain pipes 59 and 61 are connected to the return pipe 64 at a position close to the screw seat 46 as shown in FIG.

  As shown in FIG. 17, 65 is a steering switching valve located between the steering cylinders 20 and 21 and provided between the steering cylinder 21 and the steering operation valve 62. The steering switching valve 65 is, for example, manually operated by an operator. This is constituted by a four-port, three-position electromagnetic directional control valve that is switched according to the above, and controls the supply and discharge and stop of pressure oil to the steering cylinder 21 on the rear wheel side. As a result, the rear wheel 15 of the vehicle body 2 is subjected to so-called 4WS control by an arbitrary operation of the operator or control such as steering stop.

  Next, 66 is a level cylinder provided in the working device 24, and the level cylinder 66 is connected to the directional control valve 39C of the control valve device 39 in parallel with the fork cylinder 29 as shown in FIG. Yes. The level cylinder 66 is provided in the working device 24 so as to expand and contract following the boom hoisting cylinder 27, and automatically corrects the posture of the fork 26 with respect to the hoisting operation of the boom 25 shown in FIG. .

  As a result, the fork 26 of the work device 24 is tilted forward and backward by the level cylinder 66 so that the tip of the fork 19 is maintained in a substantially horizontal state even when the boom 25 is moved up and down. It is corrected. As shown in FIG. 18, a spare hydraulic cylinder 67 is connected to the direction control valve 39D of the control valve device 39, and pressure oil from, for example, the hydraulic pump 36 is also connected to the hydraulic cylinder 67 via the direction control valve 39D. Will be supplied and discharged.

  68 and 69 are hydraulic pipes connecting the working control valve device 39 and the vehicle body stabilization control valve device 40. The hydraulic pipes 68 and 69 are connected to the control valve device 39 as shown in FIGS. 40, one hydraulic pipe 68 connects the center bypass pipeline 40D of the control valve device 40 to the center bypass pipeline 39E of the control valve device 39 as shown in FIG.

  Further, the other hydraulic pipe 69 is configured such that the low pressure side pipe section 40E downstream of the direction control valve 40C in the center bypass pipe 40D shown in FIG. 18 is connected to the low pressure side pipe section 39F of the control valve device 39. To connect. The hydraulic pipe 69 is connected to the tank 38 via another hydraulic pipe 70, a return pipe 64 and the like as shown in FIG.

  The lift truck 1 according to the present embodiment has the above-described configuration, and the operation thereof will be described next.

  First, when an operator who has entered the cab 22 of the lift truck 1 starts the engine 12 while seated in the driver's seat 23, the hydraulic pumps 36, 37 and the like are driven to rotate. For example, the traveling actuator 17 including a traveling hydraulic motor, a transmission, and the like transmits the rotational driving force generated in the propeller shafts 18 and 19 to the front wheels 13 and the rear wheels 15 by supplying and discharging the pressure oil to the vehicle. The vehicle body 2 is driven to travel.

  When the operator in the cab 22 operates the steering handle 62A, the pressure oil supplied from the hydraulic pump 36 shown in FIG. 17 through the discharge pipe 48, the steering priority valve 47, and the supply pipe 49 is used for the steering operation. The gas is supplied to and discharged from the steering cylinders 20 and 21 through the valve 62. As a result, the front wheels 13 and the rear wheels 15 are steered (power steering operation), and the lift truck 1 is self-propelled to a work site or the like.

  In this case, the steering priority valve 47 is switched between the priority position (a) and the switching position (b) according to the differential pressure before and after the steering operation valve 62, that is, the differential pressure between the supply pipe 49 and the outlet pipe 63. Switch. When the steering handle 62A is operated, the differential pressure between the supply pipe 49 and the outlet pipe 63 becomes small, so that the steering priority valve 47 is held at the priority position (a).

  On the other hand, when the steering wheel operation is released, the differential pressure increases, so that the steering priority valve 47 is switched from the priority position (a) to the switching position (b). In this state, when a load (not shown) or the like is loaded on the fork 26 of the working device 24, the fork 26 is inserted below the load by slowly moving the vehicle toward the load. Arrange as follows.

  At this time, the steering priority valve 47 is switched from the priority position (a) to the switching position (b), and pressure control oil from the main hydraulic pump 36 is supplied to the work control valve device via the supply pipe 50. The sub hydraulic pump 37 also supplies pressure oil into the supply pipe 50 through the discharge pipe 52, the unload valve 51 and the junction pipe 53.

  In this state, for example, when the directional control valve 39C shown in FIG. 18 is switched in the working control valve device 39, the pressure oil from the hydraulic pumps 36 and 37 is supplied to and discharged from the fork cylinder 29. Can be driven in the extending direction. Then, by slightly extending the fork cylinder 29, for example, the fork 26 is rotated slightly upward at the front end side of the working device 24 shown in FIG. 1, and the luggage is loaded on the upper side of the fork 26 in a stable state. be able to.

  Further, when carrying out a cargo handling operation for lifting a load upward (high place) using the work device 24 with the load loaded on the fork 26, the vehicle may fall down due to the influence of the weight of the load. May receive external force. In order to prevent the vehicle from falling, it is necessary to arrange the left and right stabilizers 31 and 31 so as to protrude left and right by the respective stabilizer cylinders 32 as shown in FIGS.

  Therefore, in such a case, the direction control valves 40A and 40B provided in the control valve device 40 for stabilizing the vehicle body by tilting a stabilizer operation lever (not shown) by an operator in the cab 22 (see FIG. 18). Is switched to drive the left and right stabilizer cylinders 32, 32 in the extending direction.

  As a result, each stabilizer 31 of the lift truck 1 can be driven to the left and right by the stabilizer cylinder 32 as shown in FIGS. 1 and 2, and the ground plate 33 can be grounded to the ground. It is possible to hold the vehicle body 2 in a stable state during work, and to prevent the vehicle body 2 from falling.

  Next, when the work device 24 is operated in a state where the vehicle body 2 is stabilized in this way, for example, by switching the direction control valve 39A shown in FIG. The boom 25 can be raised and lowered (up and down). If the direction control valve 39B is switched in this state, the boom telescopic cylinder 28 can be expanded and contracted, and the boom 25 of the work device 24 can be expanded and contracted in the longitudinal direction.

  Further, by switching the direction control valve 39C, the fork cylinder 29 can be expanded and contracted, and the fork 26 can be turned up and down on the front end side of the working device 24. The loaded luggage can be transported to an appropriate place (unloading place).

  Even when the boom 25, the fork 26, etc. of the working device 24 are combined and operated in this way, the working control valve device 39 and the vehicle body stabilizing control valve device 40 include the hydraulic pumps 36, Since the pressure oil from 37 is supplied at a sufficient flow rate through the merging pipe 53 and the supply pipe 50, the composite operation as described above can be performed stably.

  After the unloading of the load is completed, the operator in the cab 22 tilts the operation lever and the like to reduce the boom 25 of the work device 24 and swings (lowers) the boom 25 downward. As shown in FIGS. 1 and 2, the work device 24 can be arranged to be stored on the frame 3.

  Further, when the lift truck 1 (vehicle) is driven, the left and right stabilizers 31 and 31 are lifted upward in advance, and the respective grounding plates 33 are largely separated from the ground, thereby stabilizing the stabilizer 31 when the vehicle is running. To prevent it from getting in the way.

  Further, for example, when the work site is an inclined ground or the like, the operator in the cab 22 switches the direction control valve 40C of the control valve device 40 for stabilizing the vehicle body to tilt the pressure oil from the hydraulic pumps 36 and 37. The correction cylinder 34 can be supplied and discharged, and the tilt correction cylinder 34 can be extended and contracted on the axle housing 14 on the front wheel 13 side shown in FIG. 2 to correct the inclination of the frame 3 in the left and right directions (frame leveling).

  On the other hand, if an overload is applied to, for example, the boom hoisting cylinder 27, the boom telescopic cylinder 28, or the fork cylinder 29 during the operation of the boom 25, the fork 26, etc. of the work device 24 as described above, the unloader shown in FIG. The load valve 51 is switched from the supply position (c) to the return position (d) when the pilot pressure from the pilot pipe 55 exceeds the set pressure of the unload valve 51.

  Then, the unload valve 51 switched to the return position (d) causes the hydraulic pump 37 to be in an unloaded (no load) state by connecting the discharge pipe 52 to the return pipe 54, thereby driving the hydraulic pump 37. 12 (see FIG. 4) can be reduced, and engine stall (engine stall) can be prevented.

  By the way, such an unload valve 51 is disposed in the frame 3 of the vehicle body 2 (for example, between the vertical plates 4 and 5) together with the steering priority valve 47 and the relief valve 56. However, in the frame 3, control valve devices 39 and 40 for working and stabilizing the vehicle body are assembled together with a large number of hydraulic pipes, and a working device 24 is provided above as shown in FIG. The lower side is a space restricted by the propeller shafts 18 and 19 in the upper and lower directions.

  For this reason, the operation of mounting the plurality of control valve devices 39, 40, the steering priority valve 47, the unload valve 51, the relief valve 56, etc. in the limited space in the frame 3 together with a number of hydraulic pipes. However, it takes a lot of labor and time, and the workability at the time of assembling is bad, and the burden on the worker is increased at the time of maintenance work.

  Therefore, in the present embodiment, the steering priority valve 47, the unload valve 51, and the relief valve 56 are replaced with the discharge pipes 48 and 52, the supply pipe 50, the merging pipe as hydraulic pipes as shown in FIGS. The control valve / pipe assembly 41 is configured by assembling in advance on the mounting plate 42 together with the pipe 53, the return pipe 54, the pilot pipe 55, the relief pipe 57, the drain pipes 59, 60, 61 and the like.

  Then, the control valve / pipe assembly 41 pre-assembled in this way is placed on the right vertical plate 5 at a position lower than the bottom plate 6 of the frame 3 as shown in FIGS. 9, 10 and 15. The mounting priority plate 47, the unloading valve 51, the relief valve 56, and the plurality of pipes 48, 50, 52 with respect to the frame 3 of the vehicle body 2 are attached. , 53, 54, 55, 57, 59, etc. can be efficiently performed.

  That is, since the pre-assembled control valve / pipe assembly 41 is attached to the right vertical plate 5 of the frame 3 via the attachment plate 42, the control valve is attached to the frame and a plurality of pipes are assembled as in the prior art. It is no longer necessary to perform separate piping work. Then, the steering priority valve 47, the unload valve 51, the relief valve 56, and the plurality of pipes 48, 50, 52, only by attaching the mounting plate 42 of the control valve / pipe assembly 41 to the right vertical plate 5 of the frame 3. 53, 54, 55, 57, 59, etc. can be assembled to the frame 3 in a lump, and workability during assembly can be improved.

  The mounting plate 42 of the control valve / pipe assembly 41 includes a steering priority valve 47, discharge pipes 48 and 52, a supply pipe 50, an unload valve 51, a merging pipe 53, a return pipe 54, a pilot pipe 55, a relief. Valve 56, relief piping 57, 58, drain piping 59, 60, 61, and the like are assembled in advance.

  For this purpose, adjustment work for finely adjusting the movement of the steering priority valve 47, the unload valve 51, the relief valve 56, etc., and the arrangement of the plurality of pipes 48, 50, 52, 53, 54, 55, 57, 59 (piping) Position) adjustment work and the like can be easily performed using a wide work space such as an assembly factory, for example, instead of in the vehicle body 2.

  The control valve / pipe assembly 41 adjusts the movement of the steering priority valve 47, the unload valve 51, the relief valve 56, etc., and a plurality of pipes 48, 50, 52, 53, 54, 55, 57, In a state in which the adjustment work of the arrangement (pipe position) of 59 is completed, the mounting plate 42 is used to move the inner surface of the right vertical plate 5 laterally (left and right) with respect to the right vertical plate 5 of the frame 3. Thus, the vehicle body 2 can be attached to the frame 3 smoothly, and the workability during assembly can be improved.

  The control valve / pipe assembly 41 includes a steering priority valve 47, an unload valve 51, and a relief valve 56 together with a plurality of pipes 48, 50, 52, 53, 54, 55, 57, 59, etc. Therefore, the entire control valve / pipe assembly 41 can be compactly formed, and errors during assembly can be kept small.

  Therefore, according to the present embodiment, the steering priority valve 47, the unload valve 51, the relief valve 56, and the plurality of pipes 48, 50, 52, 53, 54, 55, 57, 59, etc. for the frame 3 of the vehicle body 2 are provided. Can be efficiently performed using the mounting plate 42, and the workability during assembly and maintenance can be greatly improved.

  In addition, the mounting plate 42 of the control valve / pipe assembly 41 is configured as an L-shaped bracket composed of a horizontal plate portion 43 and a vertical plate portion 44, so that the mounting plate 42 on the horizontal plate portion 43 is placed on the mounting plate portion 43 </ b> A. For example, the steering priority valve 47 can be assembled horizontally, and the unload valve 51 and the relief valve 56 can be assembled to the vertical plate portion 44.

  When the control valve / pipe assembly 41 is attached to the frame 3 of the vehicle body 2, the horizontal plate portion 43 of the attachment plate 42 can be disposed at a position above the propeller shaft 19 and below the work device 24. The plate portion 44 can be disposed below the working device 24 at a position on one side (for example, the right side) of the propeller shaft 19 driving force transmission shaft.

  As a result, even if flying objects such as stepping stones are generated around the propeller shaft 19, the flying objects collide with the steering priority valve 47 and the pipes 48, 52, 53, 57, etc. on the horizontal plate portion 43. Can be prevented by the horizontal plate portion 43 of the mounting plate 42, and durability and life of these pipes and valves can be increased.

  Further, the horizontal plate portion 43 of the mounting plate 42 is formed with a U-shaped notch 43D located on the base end side (vertical plate portion 44 side), so that the valve mounting of the vertical plate portion 44 is performed. The lower side of the unload valve 51 provided in the portion 44A can be disposed in the notch 43D with a gap. Thereby, it is possible to prevent the unload valve 51 on the vertical plate portion 44 side from contacting and interfering with the horizontal plate portion 43 by the notch 43D, and the durability against the vibration of the unload valve 51 and the like, the life, etc. are improved. be able to.

  Further, the horizontal plate portion 43 of the mounting plate 42 is formed with a pipe insertion hole 45 on the base end side (position close to the vertical plate portion 44) of the side plate portion 43C. Therefore, as shown in FIGS. The relief pipe 58 can be routed between the lower face of the valve 56 and the lower face side of the unload valve 51 through the pipe insertion hole 45, so that the piping work can be easily performed. The hydraulic piping can be compactly assembled to the mounting plate 42 of the control valve / piping assembly 41.

  Further, since the screw seat 46 is fixed to the side plate portion 43B of the horizontal plate portion 43 on the outer side surface (front side surface) by means of welding or the like, the pipe diameter is changed as shown in FIGS. A return pipe 64 made of a large hydraulic pipe can be detachably fixed to the screw seat 46 of the mounting plate 42, and the return pipe 64 for returning pressure oil to the tank 38 is surrounded by the screw seat 46 around the mounting plate 42. It can be arranged compactly.

  In the embodiment, the steering priority valve 47, the unload valve 51, and the relief valve 56 are assembled to the mounting plate 42 together with the plurality of pipes 48, 50, 52, 53, 54, 55, 57, 59, and the like. The case where the control valve / pipe assembly 41 is configured by attaching is described as an example. However, the present invention is not limited to this. For example, control valves other than the steering priority valve 47, the unload valve 51, and the relief valve 56 are assembled together with a plurality of hydraulic pipes to a bracket such as the mounting plate 42. You may make it comprise a control valve and piping assembly.

  Moreover, in the said embodiment, the lift truck 1 used for cargo handling work etc. was mentioned as an example and demonstrated as a self-propelled working machine. However, the present invention is not limited to this, and is widely applied to self-propelled working machines in which a driving force transmission shaft such as a propeller shaft is provided below the frame, such as a wheeled hydraulic excavator, a hydraulic crane, and a wheel loader. It can be applied.

It is a front view which shows the lift truck by embodiment of this invention. It is the perspective view which looked at the lift truck of FIG. 1 from diagonally forward on the opposite side. FIG. 2 is a front view showing a frame of a vehicle body, a control valve / pipe assembly, etc. with the front wheel, rear wheel, cab, work device, etc. in FIG. 1 removed. It is the top view which looked at the flame | frame in FIG. 3, a control valve, piping assembly, etc. from upper direction. It is the bottom view which looked at the flame | frame in FIG. 3, a control valve, piping assembly, etc. from the downward direction. FIG. 5 is a cross-sectional view of the frame, the control valve / pipe assembly, and the like when viewed from the direction of arrows VI-VI in FIG. 4. It is a plane enlarged view which shows the control valve and piping assembly in FIG. 4 with a part of flame | frame. FIG. 6 is an enlarged bottom view showing the control valve / pipe assembly in FIG. 5 together with a part of the frame. It is the perspective view which looked at the state which attached the control valve and piping assembly to the flame | frame from diagonally forward. It is a perspective view which expands and shows the control valve and piping assembly in FIG. It is a perspective view which shows the control valve and piping assembly in FIG. 10 as a single unit. It is a perspective view which shows the attachment plate in FIG. It is the top view which looked at the mounting plate of FIG. 12 from the upper side. FIG. 14 is a right side view of the mounting plate shown in FIG. 13. It is a perspective view which shows the state in the middle of attaching the control valve and piping assembly in FIG. 10 to a flame | frame. It is the perspective view which looked at the control valve, piping assembly, etc. of FIG. 11 from the opposite side. FIG. 3 is a hydraulic circuit diagram showing a steering priority valve, an unloading valve and a relief valve that constitute a control valve / pipe assembly together with a hydraulic pump, hydraulic piping, and the like. FIG. 18 is a hydraulic circuit diagram showing a plurality of directional control valves constituting the work valve stabilizing control valve device in FIG. 17 together with each cylinder of the work device.

Explanation of symbols

1 Lift truck (self-propelled work machine)
2 Car body 3 Frame 4 Left vertical plate 5 Right vertical plate 6 Bottom plate 12 Engine (motor)
13 Front wheel 15 Rear wheel 17 Traveling actuator (traveling hydraulic actuator)
18, 19 Propeller shaft (drive force transmission shaft)
20, 21 Steering cylinder (hydraulic actuator for steering)
22 cab 24 working device 25 boom 26 fork (loading work implement)
27 Boom hoisting cylinder (hydraulic actuator)
28 Boom telescopic cylinder (hydraulic actuator)
29 Fork cylinder (hydraulic actuator)
36, 37 Hydraulic pump (hydraulic power source)
38 Hydraulic oil tank 39 Control valve device for work 40 Control valve device for vehicle body stability 41 Control valve / pipe assembly 42 Mounting plate (bracket)
43 Horizontal plate portion 43D Notch 44 Vertical plate portion 45 Pipe insertion hole 46 Screw seat 47 Priority valve for control (control valve)
48,52 Discharge piping (hydraulic piping)
49, 50 Supply piping (hydraulic piping)
51 Unload valve (control valve)
53 Junction piping (hydraulic piping)
54, 64 Return piping (hydraulic piping)
55 Pilot piping (hydraulic piping)
56 Relief valve (control valve)
57, 58 Relief piping (hydraulic piping)
59, 60, 61 Drain piping (hydraulic piping)
63 Lead piping (hydraulic piping)

Claims (7)

Pressure oil is supplied / exhausted from a vehicle body frame, front and rear wheels, and a hydraulic power source, which are rotatably driven on the lower side of the frame and driven forward and rearward through a driving force transmission shaft. Thus, a traveling hydraulic actuator that rotationally drives the driving force transmission shaft, a steering hydraulic actuator that steers the wheel by pressure oil from the hydraulic source, and a working hydraulic pressure provided on the upper side of the frame Self-propelled comprising an operation device driven by an actuator, and a plurality of control valves that are provided between the hydraulic source and each hydraulic actuator via a plurality of hydraulic pipes and control the operation of each hydraulic actuator. In the type work machine,
A control valve / pipe assembly is constructed by assembling at least a part of the plurality of control valves together with a plurality of hydraulic pipes into a single bracket,
The control valve / pipe assembly is configured to be detachably mounted using the bracket at a position in the frame that is above the driving force transmission shaft and below the work device. Type work machine.   The frame is composed of a pair of vertical plates that are spaced apart left and right and extend in the front and rear directions, and a bottom plate that connects the pair of vertical plates in the left and right directions, and the control valve / pipe assembly is The self-propelled working machine according to claim 1, wherein the self-propelled working machine is configured to be attached to one of the pair of vertical plates.   The some control valves are switched to reduce a load on a steering priority valve that supplies pressure oil from the hydraulic source with priority to the steering hydraulic actuator and a prime mover that drives the hydraulic source. The self-propelled working machine according to claim 1 or 2, comprising an unloading valve.   The bracket of the control valve / piping assembly includes a horizontal plate portion that is assembled in a state where one control valve of the plurality of control valves is disposed horizontally, and another bracket that is provided perpendicular to the horizontal plate portion. A vertical plate portion to which a control valve is assembled, the horizontal plate portion is disposed above the driving force transmission shaft and below the working device, and the vertical plate portion is disposed on the working device. The self-propelled work machine according to claim 1, 2 or 3, wherein the self-propelled work machine is configured to be disposed on one side of the drive force transmission shaft on the left and right sides below the right side.   The self-propelled working machine according to claim 4, wherein the horizontal plate portion of the bracket is provided with a notch for inserting a valve in which the control valve assembled to the vertical plate portion is disposed with a gap.   The self-propelled working machine according to claim 1, 2, 3, 4 or 5, wherein the bracket is provided with a piping insertion hole for hydraulic piping connected between the control valves.   7. The bracket according to claim 1, wherein the bracket is provided with a screw seat for fixing a hydraulic pipe different from the hydraulic pipe connected between the control valves. Traveling work machine.

Images