WO1999050509A1

WO1999050509A1 - Hydraulic shovel

Info

Publication number: WO1999050509A1
Application number: PCT/JP1998/004132
Authority: WO
Inventors: Hiroyuki Arita; Masato Nakashima; Akio Oshima
Original assignee: Shin Caterpillar Mitsubishi Ltd.
Priority date: 1998-03-30
Filing date: 1998-09-14
Publication date: 1999-10-07

Abstract

Hydraulic shovel, in which, when optional functions are to be added by using an optional valve of a hydraulic shovel, ease of operation as an automatic system is improved without impairing its light weight and compactness; comprising an auxiliary spool working means having a hydraulic cylinder means (24) and provided between a spool working means and a valve unit (18), and a selector valve (14) for blade disposed on the path of oil supplied from a hydraulic pump via an auxiliary valve (19) while the auxiliary spool working means is connected to the auxiliary valve (19), wherein the tilt-angle operation of a blade (10) can be carried out by selecting, by switching operation of a control lever (L), between pressure oil supply to hydraulic cylinders (11L, 11R) for angle of the blade (10) and that to a hydraulic cylinder (12) for tilting.

Description

Description '-Hydraulic excavator technical field

The present invention belongs to the technical field of a hydraulic control device for a hydraulic shovel, particularly a small hydraulic shovel.

In general, a hydraulic excavator or the like is provided with a plurality of hydraulic actuators and works by appropriately combining the hydraulic actuators. The hydraulic oil supply control to each hydraulic actuator is controlled. These valves are centrally mounted on one knoll base and mounted on the aircraft.

By the way, in such a hydraulic excavator, a dozer work using a dozer blade (blade) may be performed separately from the bucket work. In order to cope with such a situation, the dozer blade needs to be moved up and down on the valve base. It is essential to provide a valve and a spool operating means for operating the spool of the valve, and these are usually provided as standard. Some of these dozer blades have special specifications that have a tilt function to raise or lower one side or an angle function to move back and forth, but these special specifications are optional as requested by users and others. It is generally equipped.

On the other hand, the valve base is provided with a spare valve (optional valve) for taking out the external hydraulic pressure in order to support various attachments such as a dozer blade, a hydraulic breaker, pressure, and a pile punching machine. Generally, a spare knob is used to provide the above functions.

By the way, as shown in FIGS. 23 (A) and (B), the spool actuation means of the spare valve includes a pedal operating part 44 (or lever operation) provided on the spool 19 a of the spare valve 19. And the pedal operation section 4 4 can be operated manually (foot movement). And a manual spool actuating means for switching by means of Here, especially in a small hydraulic excavator, it is common to have one spare valve 19 due to space and other reasons. In this case, in order to add a tilt-angle switching function to the dozer blade, a tilt-to-angle switching function is required. It is necessary to provide a selector valve, and therefore, in addition to the manual switching operation of the spare valve 19, a switching operation for switching the selector knob is separately required, which makes the operation complicated and complicated, resulting in poor operability. There is a problem, and here is the subject of the present invention.

Therefore, in order to solve the above-mentioned problem, it is proposed that the switching of the reserve valve be replaced with an automatic switching instead of a manual operation such as a stepping operation of a pedal, so that the selector valve can be switched in conjunction with the switching operation. Is done. However, in this case, it is difficult to secure the space for installing the automatic switching mechanism that switches the spare valve, and if it is attempted to secure it at a position close to the spare valve, it is difficult because the piping of the hydraulic hose is in the way. However, there is a problem that a link error or the like may be generated and smooth operation may not be performed, and there is a problem.

In addition, when an option that operates hydraulically such as a brake force is to be installed as an option in place of a bucket attached to the tip of the arm, for example, the hydraulic cylinder for brake force is connected. The spare knob is no longer used. As a result, there is a problem that the blade cannot be provided with both the tilt and angle operation and the breaker operation of the blade, and there is a problem to be solved by the present invention. Disclosure of the invention

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has been created with the object of solving these problems. In addition to disposing blades that move up and down by operating the operating lever, a valve unit is provided with centralized equipment for each valve for controlling the supply of hydraulic oil from the hydraulic pump to a plurality of hydraulic factories. In a hydraulic excavator having a spool operating means for operating each valve spool on one side of a blade, a hydraulic cylinder for tilt and a hydraulic cylinder for angle are provided on the blade. In order to supply the hydraulic oil to these hydraulic cylinders, and to provide the function of changing the tilt angle posture by supplying hydraulic oil to these hydraulic cylinders, in order to supply hydraulic oil to the tilt and angle hydraulic cylinders, the optional valve provided on the valve unit is used. And an auxiliary spool operating means for operating a spool of the optional valve is disposed between the spool operating means and a valve unit which is centrally mounted.

By doing so, the auxiliary spool actuating means can be arranged close to the spool of the option valve, and the spool actuating means without any looseness can be performed.

In this, the auxiliary spool operating means of the present invention includes a solenoid, hydraulic cylinder means switched by the operation of the solenoid, a cylinder rod of a cylinder constituting the hydraulic cylinder means, and a spool of an optional valve. And the hydraulic cylinder means are disposed between the spool operating means and the valve unit, and the connecting means is arranged in parallel with the spool operating means. can do.

Further, in this apparatus, a selector for a blade for supplying pressure oil from a hydraulic pump to a tilt and angle hydraulic cylinder is provided in an oil passage from an option valve switched by the auxiliary spool operating means of the present invention. A valve is connected to the selector valve for the blade, and a pilot switching valve for switching the selector valve for the blade is provided. The auxiliary spool operating means and the pilot switching valve are selectively switched between tilt and angle operations. An operation switch operated to output a command may be provided. Thereby, the auxiliary spool operating means and the pilot switching valve can be switched by operating the operation switch, thereby improving operability.

Further, in this case, the operation switch of the present invention can be provided on a grip portion of an operation lever for moving the blade up and down, whereby the blade can be moved up and down, tilted. Operation and angle operation can be combined into one operation lever, and operability is further improved.

Still further, in this apparatus, a delay time is set for the output of the switching command to the auxiliary spool operating means by operating the operation switch of the present invention. When switching the tilt toe angle, it is possible to avoid a problem that the auxiliary spool operation stage is switched earlier than the pilot switching valve.

Further, in this apparatus, the pressure oil from the option valve of the present invention is selectively switched and supplied to an option hydraulic operation mechanism different from tilt and angle operations and to the blade selector knob. And a switching means for switching the optional selector valve based on the operation of the operating tool. Pressure oil from the valve can be selectively supplied to the optional selector valve in addition to the blade selector valve.

Further, in this apparatus, the optional valve and the optional selector valve of the present invention are such that when the operating tool is operated to operate the optional hydraulic operating mechanism, the optional valve is switched after the optional selector valve is switched. It may be controlled to be switched. BRIEF DESCRIPTION OF THE FIGURES

Fig. 1 is a perspective view of a hydraulic excavator, Fig. 2 is a plan view with the upper revolving structure removed, Fig. 3 is a view taken in the direction of arrows A-A in Fig. 2, and Figs. B-B cross-section, C-C cross-section, Fig. 5 is a perspective view of the blade part, Fig. 6 is a plan view of the valve unit, Fig. 7 is a plan view of the main part, Fig. 8 is a side view of the main part, 9 (A) and 9 (B) are perspective views of the operating lever portion, a perspective view of the grip portion of the operating lever, FIG. 10 is a block diagram showing a control state in the blade control portion, and FIG. 11 is a blade. Hydraulic circuit diagram for attitude control, Fig. 12 is an explanatory diagram of the operation of the arm, Fig. 13 is a plan view showing the battery mounted state, Figs. 14 (A) and (B) are side views showing the battery mounted state, respectively. FIG. 15 is a front view, FIG. 15 is a hydraulic circuit diagram of blade attitude control according to the second embodiment, and FIG. 16 is a hydraulic circuit diagram of the third embodiment. FIG. 17 is a side view of the bell, FIG. 17 is an enlarged plan view of a main part according to the third embodiment, FIG. 18 is a view taken along the arrow A in FIG. 17, and FIG. 19 is a control unit according to the third embodiment. FIG. 20 is a control block diagram showing a control state in the control unit in the third embodiment, and FIG. 21 is a block diagram showing a control state in the third embodiment. FIG. 22 is a hydraulic circuit diagram of blade attitude control and breaker operation control according to the embodiment, FIG. 22 is a perspective view of a part of an operation lever according to the fourth embodiment, and FIGS. 23 (A) and (B) are conventional figures. It is the top view and side view which show an example. BEST MODE FOR CARRYING OUT THE INVENTION

Next, embodiments of the present invention will be described with reference to the drawings.

First, a first embodiment is shown in FIGS. 1 to 14, in which 1 is a small hydraulic excavator body, and the body 1 is a crawler type lower traveling body 2, Upper revolving structure 3 provided on lower traveling structure 2 for free rotation, operation formed on upper revolving structure 3 され It is composed of various member devices such as mulberry vertical section 4 and working section 5 extending from upper revolving structure 3. All are the same as before.

Reference numeral 6 denotes a pair of left and right arms which support the lower traveling body 2 so that the S¾ portion is pivotable up and down. A bracket 7 is physically connected between the distal ends of the arms 6. A tilt support shaft 8 whose axis is oriented in the front-rear direction is rotatably supported on the lower side of the bracket 7 at the front center in the left-right direction so as to be rotatable around the axis. The front end of the tilt support shaft 8 is The bracket (dozer blade) 10 is provided with a bracket 10a provided on the rear surface of the blade 10 via an angle support shaft 9 whose axis is oriented in the vertical direction. Supported.

11 L and 11 R are left and right angle hydraulic cylinders, and each of the hydraulic cylinders 11 L and 11 R is connected to each arm 6 whose ¾i portion is supported via a support shaft 11 a. It is swingably supported, and its front end is swingably supported on the right and left back surfaces of the blade 10 via support shafts 11b. As will be described later, the left and right angle cylinders 11 L and 11 R perform reciprocal expansion and contraction, so that the blade 10 swings forward and backward with the angle support shaft 9 as a fulcrum. In the meantime, the blade 10 is configured to have an angle posture in which the left and right positions are inclined forward and backward.

On the other hand, reference numeral 12 denotes a hydraulic cylinder for tilt. The hydraulic cylinder 12 includes a support shaft 12 provided on the bracket 7 so that the S portion is concentrically located with respect to the support shaft 9 for angle. a is pivotally supported by a, while the tip is positioned concentrically with respect to the support shaft 1 lb that supports the tip of one of the angle hydraulic cylinders 11 (left side in this embodiment). W

In this relation, the blade 10 is swingably supported by a support shaft 12 b provided on the blade 10. When the tilt hydraulic cylinder 12 expands and contracts as described later, the blade 10 swings up and down around the tilt support shaft 8, thereby changing to a tilt posture. You can now. Reference numeral 13 denotes a hydraulic cylinder for vertically moving up and down the blade provided between the lower traveling body 2 and the bracket 7a.

Each of the hydraulic cylinders 11 L, 11 R, and 12 is connected by piping to a later-described blade selector valve 14 attached to the left arm 6 as an external member. 4 further includes a pilot pressure oil force bracket 16 and an operating pressure oil force bracket 17 provided for an optional attachment to a rotary joint 15 provided between the undercarriage 2 and the upper revolving superstructure 3. It is connected to a pipe, which allows each hydraulic cylinder 11 L, 11 R, 12 and a spare valve (optional valve of the present invention) 19 pre-installed in a valve unit (main valve) 18 described later. Force; connected to configure the oil path for tilting and changing the attitude of blade 10.

The valve unit 18 has a plurality of valves assembled and assembled in a row (centralized equipment). The valve unit 18 has a valve base 20 fixed to the lower surface thereof and a rubber damper 2. It is fixed to the main frame 3a of the upper swing body 3 with 0a interposed. The valve unit 18 is, for example, a valve for controlling the supply of pressurized oil to the working unit 5 or a valve for controlling the supply of pressurized oil to the rotary joint 15 and the rotary motor 15a. A plurality of knob spools 18a of these knob groups are arranged so as to protrude inward in the left-right direction of the fuselage. The above-mentioned spare knob 19 is arranged.In the figure, 15b is a turning circle.

Reference numeral 21 denotes a bracket positioned inside the valve unit 18 and fixed to the valve base 20. The bracket 21 includes two first and second phosphors in a state of being arranged vertically. Shafts 22 and 23 are supported. The first and second link shafts 22 and 23 are formed to be long left and right, and a plurality of link bosses 22a and 23a are rotatably supported in a state of being adjacent to each other: ^ One link arm 2 2b, integrally formed with the link boss 2 2a, 2 3a 23 b are respectively connected to the corresponding valve spools 18a via connecting links 22c and 23c. Then, each link boss 2 2a, 23 a swings based on each operation such as an operation lever connected to the other link arm 2 2d, 23 d, whereby a necessary valve is provided. It is set so as to perform the valve switching operation by performing the push / pull operation of the spool 18a, and thus the spool operating means is constituted.

Then, of the link bosses 22 a pivotally supported by the first link wheel 22 located on the upper side, one of the link bosses (lower side in FIG. 6) faces the spare valve 19. The opposite link boss constitutes an auxiliary spool operating means of the present invention as a spare link boss 22e, and pushes and pulls the spare spool 19a to operate the spare valve 19 as described later. It is configured to switch. That is, a spare link arm 22 f is physically protruded from the other side of the spare link boss 22 e, and the spare link arm 22 f is provided via the connecting link 22 g. It is linked to the spool 19a. On the other hand, a pair of link arms 22 h and 22 i projecting up and down is formed on one side of the link boss 22 e, and one of these link arms 22 h and 22 i is formed. A connecting means is constituted by connecting an operating means for moving the link boss 22 e to one of them, and in this embodiment, a hydraulic cylinder means 24 described later is attached to the lower link arm 22 i. By being connected, the spare link boss 22 e swings based on the operation of the hydraulic cylinder means 24, whereby the spare spool 19 a is pushed and pulled to actuate the spare lube 19. The hydraulic cylinder means 24 is constituted by an operating hydraulic cylinder 25 and an electromagnetic switching valve 26 disposed on the upper surface thereof. Is one side of the valve unit 18, and the valve unit 18 and the first and second link shafts 2 2, 2 3, and is provided via an upright piece 27a of a substantially L-shaped mounting bracket 27 fixed on the valve base 20 at the corresponding portion. The operating hydraulic cylinder 25 is composed of a cylinder cylinder 25a and a cylinder load 25b, and the cylinder end of the cylinder cylinder 25a is fixed in abutting manner to the upright piece 27a. The cylinder rod 25b projects rearward while penetrating the upright piece 27a, and the projecting end portion 25c is connected to the lower link arm 22i of the spare link boss 22e. 5d, and the auxiliary spool actuation in which the connecting means and the hydraulic cylinder means 24 are connected. Means are configured.

The hydraulic cylinder means 24 is a three-position switching valve having a Φ standing position provided for left and right operation, and an electromagnetic switching valve 26 corresponding to a first pilot switching valve described later. When the solenoids 26 L and 26 R operate, hydraulic oil is supplied to the cylinder cylinder 25 a, and based on this, the cylinder rod 25 b moves to move through the lower link arm 22 i. Thus, the spare link boss 22 e is swung to push and pull the spare spool 19 a, so that the spare valve 19 can be automatically switched.

Incidentally, the spool actuating means includes a spare spool 19 a, which is provided in advance, a spare link boss 2 2 e, a link arm 22 f, a connecting link 22, and upper and lower link arms 22 h and 22 i. Is already attached. In the case where the pedal device 44 is provided on the upper link arm 22 h, the configuration is the same as that of the conventional example, but in the form of the present sickle, not only the upper link arm 22 h but also the lower side The link arm 22 i facing the body is formed so that when the pedal device 44 is removed, the hydraulic cylinder means 24 is connected to the lower link arm 22 i so that the necessary By performing piping, it is possible to change to a configuration in which the spare valve 19 is automatically switched and operated.

L is an operation lever disposed on the operation control section 4, and the operation lever L is configured to operate the hydraulic cylinder 13 for vertically moving the blade up and down by operating the front and rear directions. ing. Further, the grip portion of the operation lever L is provided with four operation switches, that is, tilt operation switches 28 and 29 and angle operation switches 30 and 31. These operation switches 28, 29, 30 and 31 are connected to a blade control unit 32 configured using a micro-computer and the like. A setting for outputting a control signal to the first pilot switching valve (electromagnetic switching valve of auxiliary spool operating means) 26 and a second pilot switching valve 33 described later based on the input of the switch signal of the operation switch 28 to 31 It has become.

Here, the second pilot switching valve 33 is connected to the selector valve 14 for the blade, and switches the selector valve 14 for the blade to either the tilt side or the angle side, but one switching solenoid 33 3 a two-position switching valve with a When the solenoid 33a is not in operation, it is switched to the side (tilt side) for supplying hydraulic oil to the tilt hydraulic cylinder 12 as described later by receiving the urging force of the return spring 3b. It has become.

Next, a hydraulic circuit to the angle hydraulic cylinders 11 L and 11 R and the tilt hydraulic cylinder 12 will be described with reference to FIG. In the figure, Pm is a main hydraulic pump, and Ps is a sub-hydraulic pump, both of which are activated based on the driving of an engine (not shown). The oil is supplied to a spare valve 19 serving as a main switching valve, and the oil is supplied to the selector valve 14 for the blade by switching the spare valve 19.

On the other hand, the switching of the reserve valve 19 is performed by supplying the pilot pressure oil from the sub-hydraulic pump Ps to the operating hydraulic cylinder 25 serving as a pilot cylinder as described above. The operating hydraulic cylinder 25 is switched in response to switching of the first pilot switching valve (electromagnetic switching valve) 26 corresponding to tilt or angle operation. The selector knob 14 is for switching the supply of pressurized oil to the tilt hydraulic cylinders 12 or the angle hydraulic cylinders 11 L and 11 R. The second pilot switching valve 33 is executed by the switching operation.

That is, when none of the operation switches 28 to 31 is operated, the first pilot switching valve 26 is switched to the neutral state, and the second pilot switching valve 33 is switched to the tilt position side. ing. In this state, the second pilot switching valve 33 closes the pilot pressure oil supply oil passage 14 a from the sub hydraulic pump P s to the selector valve 14 while the pilot tank oil passage 1 As a result, the selector valve 14 receives the urging force of the return spring 14 c and the oil passage 14 d leading to the spare valve 19 is connected to the tilt hydraulic cylinder 12. It is located at the tilt side position communicating with the oil passage 14 e for supplying the pressurized oil. However, since the spare valve 19 is in the neutral state, the hydraulic pressure is not supplied from the main hydraulic pump Pm, and the tilt operation is not performed.

In this state, when one of the tilt operation switches 28 and 29 is pressed and operated, The operation signal is input to the blade control unit 32, and based on this, the first and second pilot switching valves 26, 33 are switched, but in the non-operation state, the valve is already switched to the tilt side. The operation command is not output to the changing second pilot switching valve 33 and is kept in the OFF state, whereas the first pilot switching valve 26 is set to one of the corresponding ones. An operation command is output to the solenoids 26 L and 26 R, and the output is output by a delay time T (for example, 0.5) preset by a delay circuit 32 a incorporated in the blade controller 32. The output is delayed by a second). Then, when the first pilot switching valve 26 is switched to the corresponding side, the pilot pressure oil is supplied to the operating hydraulic cylinder 25, and based on this, the spare valve 19 is switched to the corresponding side. When opened, pressure oil from the main hydraulic pump Pm is supplied to the side of extending or contracting the hydraulic cylinder for tilt 12, whereby the blade 10 is tilted such that one of the left and right is raised upward. It is set to transform into a posture.

On the other hand, when one of the angle operation switches 30 and 31 is operated, the blade controller 32 outputs the operation command of the solenoid 33 a of the second pilot switching valve 33. When the second pilot switching valve 33 is switched based on this, the pilot pressure oil supply oil passage 14a of the selector valve 14 is opened, and the pilot pressure oil from the sub hydraulic pump Ps is supplied. The selector valve 14 switches to the angle side position. On the other hand, when the delay time T has elapsed since the switch operation was performed, the blade controller 32 changes the solenoids 26 L and 26 R on the corresponding side to the first pilot switching valve 26. An operation command is output to any one of the above, and the pilot hydraulic oil from the sub hydraulic pump Ps is supplied to the operating hydraulic cylinder 25. Based on this, the spare valve 19 opens to the corresponding side, and the hydraulic oil from the main hydraulic pump Ps is supplied to the corresponding angle hydraulic cylinders 11 L, 11 R, whereby the blade 10 Is set so that either one of the left and right sides is in the front posture.

A throttle valve 34 is provided in the pilot pressure oil supply oil passage 14a of the selector valve 14 so as to avoid a sudden switching of the selector valve 14 and to perform a smooth switching without shock. Due to this, the self-delay time T is set to a value corresponding to this switching time (slightly longer than the switching time). In this case, as shown in FIG. 12, the following consideration is given to the working unit 5. That is, an arm 36 6 is pivotally supported at the tip of the boom 35, which is swingably supported by the upper revolving structure main frame 3 a, via the swing shaft 36 a, and the arm 36 is The boom 35 and the arm 36 are substantially displaced from the bending posture (solid line) that swings downward with the swing shaft 36 a as the fulcrum due to the expansion and contraction of the arm cylinder 37 provided to the boom 35. It is configured to swing up and down in a straight extended posture (virtual line). On the other hand, a bucket cylinder 38 is provided on the arm 36, and the bucket 39, which is supported on the tip end of the arm 36, is oscillated in accordance with the expansion and contraction of the bucket cylinder 38, but the bucket cylinder 38 is provided. The pipe 38a for supplying pressure oil to the cylinder 38 is drawn out from the main frame 3a side, and passes through the arm 3 via one side of the boom 35 and the upper side of the swing shaft 36a. 6 and connected to the bucket cylinder 38 in this way. In this apparatus, a piping guide body 36b is provided at the S¾ portion of the arm 36, and the guide 36b is set so that the upward movement of the piping 38a is regulated. ing. For this reason, the pipe 38 a, which is dimensioned to be just the right length in the bent position of the arm 36, will have a surplus due to the transformation of the arm 36 to the extended position, and will escape upward. It is set so as to restrict this in the case where it is set to be so that flapping and damage of the pipe 38a is avoided.

Further, in this device, as shown in FIGS. 13 and 14, the following considerations are also made in the fixing structure of the battery 40 mounted on the upper-part turning body 3. That is, the fixing plate 41 is addressed to the upper surface of the battery 40, and vertically long fixing bolts 42 are inserted into both sides of the fixing plate 41 located outside the battery 40, and the fixing bolts 41 The main frame 3a is fixed to the main frame 3a by locking the distal end 42a to a locking portion 3b provided on the main frame 3a. As a result, the battery 40 has an advantage in that the vertical movement is restricted, and the battery 40 can be prevented from sticking and being displaced. Further, a cushion member 43 interposed between the side surface of the battery 40 and the side surface of the main frame 3a is interposed in the fixing bolt 42, and the size of the cushion member 43 is reduced. It is set so that it can respond to changes in battery size by changing it.

In the first embodiment of the present invention configured as described above, the blade 10 is tilted. — To implement an option that has an angle function (specification) 5 The spare valve 19 will be used for tilt-angle attitude control, and the spare spool 19 a will be provided with auxiliary spool actuation In this case, the hydraulic cylinder means 24 controlled by the operation of the operating lever L is attached as the auxiliary spool operating means, and the switching of the hydraulic cylinder means 24 is performed. By connecting the protruding end 25c of the cylinder load and the lower link arm 22e, it can be easily installed.

Moreover, in this case, the hydraulic cylinder means 24 is provided with a conventional dead space formed between the valve unit 18 and the first and second link shafts 22, 23 on one side of the valve base 20. Space can be used effectively, and there is no need to secure a separate space for mounting the hydraulic cylinder means 24, and it can be provided in the vicinity of the spare valve 19 can be smoothly push pull operation of the spare spool 1 9 a a (switching operation) can cause fi ^1.

In addition, the auxiliary spool operating means is fixed together with the valve unit 18 on the valve base 20 provided via the damper 20a in order to avoid vibration from the body frame 3a. Since the operating means is vibration-isolated together with the valve unit 18, even if it vibrates, the same vibration state is obtained, so that a smooth spool operation can be realized and the tilt operation can be controlled accurately.

Further, in this device, a link arm 22 d, a spare link boss 22 e, and upper and lower link arms 22 h and 22 e are provided in advance on the spare spool 19 a as standard equipment. Therefore, the operation mode can be freely changed by selectively providing a manual type that connects the pedal device or the like or an automatic type that connects the hydraulic cylinder means 15 as necessary, and the change work is easy. Can be.

In this device, the operation switch 28 to 31 provided on the operation lever L is a first pilot which is an electromagnetic switching valve of the hydraulic cylinder means 24 for switching the spare spool 19 a of the spare valve 19. In addition to being connected to the switching valve 26, it is connected to the second pilot switching valve 33 for switching the blade selector valve 14 and is operated by one operation switch 28-31. The switching control of the corresponding first and second pilot switching valves 26, 33 can be performed, and as a result, the blade 1 When changing 0 to the tilt posture or the angle posture, the operability is improved because the operator only needs to selectively press the necessary operation switches 28 to 31. Moreover, in this device, since these operation switches 28 to 31 are collectively arranged on the grip of the operation lever L for moving the blade 10 up and down, the operation switch for operating the blade 10 is operated. The operability is further improved because the operations are concentrated.

In addition, when the operation switches 28 to 31 are operated, the first pilot switching valve 26 is switched after the second pilot switching knob 33 is switched, so that the angle-tilt operation is switched. In this case, pressure oil is not supplied to the hydraulic cylinder before switching at the beginning of operation, and smooth cylinder operation can be performed.

The present invention is not limited to the above-described first embodiment, and may also be a second Hi¾ type shown in FIG. 5¾ can be. In this device, a second pilot switching valve 45 for switching the blade selector valve 14 is constituted by a three-position switching valve having a neutral position. In this device, a second pilot switching knob is provided. 4 5 is in a neutral state when the switch is not operated and is not operated, and when the operation switches 28 to 31 are operated, the pilot pressure is switched to switch the blade selector valve 14 to the corresponding side. It opens an oil passage and can be implemented in this way.

Next, a third embodiment is shown in FIG. 16 to FIG. 22. In the drawings, the same reference numerals are given to components common to (same as) the first embodiment. The details will be omitted with the withdrawal.

The machine body 1 of the present embodiment is provided with a breaker 46 as an attachment (option attachment) in place of the bucket at the tip of the working section 5, and the oil passage for operating the breaker 46 is the same as that described above. It is provided in a state where it is added to an oil passage for changing the attitude of the blade 10 using the spare valve 19.

That is, as described above, the first and second pilot switching valves 26 based on the operation of the operation lever L are provided for the oil passages for changing the blade 10 into the angle posture and the tilt posture. The pressure oil is supplied to the angle cylinders 11 L, 11 R, and the tilt cylinder 12 via the spare valve 19 by switching between, 33. These configurations are the same as those of the first embodiment.

On the other hand, the breaker 46 is detachably supported by an arm 36 constituting the working unit 5, and the breaker 46 is provided with a hydraulic operating mechanism (breaker operating mechanism). When the pressurized oil is supplied to the cylinder 47, the chisel 46a provided at the tip of the breaker 46 vibrates, so that breaker work such as crushing is performed. The piping from the hydraulic cylinder 47 for the breaker passes through an arm 36 and a boom 35 constituting the working unit 5 and a selector valve for a breaker disposed in front of the upper revolving unit 3 (an option of the present invention). (Equivalent to the selector valve part.) The breaker selector valve 48 is connected to an oil passage between the externally provided blade selector valve 14 and the spare valve 19, and is connected to the hydraulic fluid supplied through the spare valve 19. Is selected and supplied to either the blade selector valve 14 side or the breaker hydraulic cylinder 47 side.

On the other hand, reference numeral 49 denotes a pedal corresponding to the operating tool of the present invention provided on the floor of the driving control section 4, and the breaker operation of the chisel 46a is performed by depressing the pedal 49. It is set. That is, the pedal 49 has a structure in which an intermediate portion of a pedal plate 49 a which is long in the front-rear direction is swingably supported on the floor via the support shaft 49 b.

When either the front or the rear of the pedal plate 49a is depressed with the 49b as a fulcrum, the breaker operation switches 50 and 51 are set to be switched. The switches 50 and 51 are connected to a breaker control unit 52. The break force control unit 52 switches the switch signals from the breaker operation switches 50 and 51. Is input, a third pilot switching valve for switching the first pilot switching valve 26 and the breaker selector valve 48 based on the input signal.

It is set to output the control signal to 53.

Incidentally, the breaker control unit 52 is housed in the lower part of the operation lever L. The third pilot switching valve 53 is connected to the breaker selector valve 48, and the breaker selector valve 48 is connected to either the breaker hydraulic cylinder 47 or the blade selector valve 14. It is set to switch to. Also, third party The throttle switching valve 53 is composed of a two-position switching valve having one switching solenoid 53a, and receives the urging force of the return spring 53b when the solenoid 53a is not operated. In this state, as described later, the setting is made so that the pressure can be switched to supply the pressure oil to the blade selector valve 14 side (blade side).

Next, a hydraulic circuit for controlling hydraulic oil to the hydraulic cylinder for tilt, the hydraulic cylinder for angle 10 R, 10 L, and the hydraulic cylinder 26 for brake force will be described with reference to FIG. 21. explain. Each of the hydraulic pumps Pm and Ps is started based on the driving of an engine (not shown), and the hydraulic oil discharged from the main hydraulic pump Pm is supplied to the auxiliary valve 19, and the auxiliary valve 19 The oil passage is formed so as to be supplied to the breaker selector valve 48 side based on the switching of the above.

The pressure oil supplied to the breaker selector valve 48 is switched to be supplied to the breaker hydraulic cylinder 47 or the blade selector valve 14 based on the switching of the breaker selector valve 48. The operation is set to be performed by the third pilot switching valve 53. Then, the pressure oil that has passed through the breaker selector valve 48 is switched by the blade selector valve 14 so as to be supplied to the tilt hydraulic cylinder 12 or the angle hydraulic cylinders 11 L and 11 R. The switching of the blade selector valve 14 is performed by switching the second pilot switching valve 33 in the same manner as in the first embodiment.

In this case, if the operation lever L and the pedal 49 are not operated and none of the operation switches 28 to 31, 50 and 51 are operated, the first pilot switching valve 26 is not operated. In the neutral state, the third pilot switching valve 53 is switched to the blade side position, and the second pilot switching valve 33 is switched to the tilt side position. In this state, the third pilot switching valve 53 closes the pilot pressure oil supply oil passage 48a from the sub-hydraulic pump Ps to the breaker selector valve 48, whereby the breaker selector valve 4 8 is set so as to be positioned on the blade side communicating with an oil passage 14 d communicating with the blade selector valve 14 by receiving the urging force of the return bomb 48 b.

In this state, when a switch is operated from operation lever L, the operation signal Is input to the blade control unit 32, and based on this, the force ^{s at} which the switching control of the first and second pilot switching valves 26, 33 is performed. At this time, the third pilot switching valve 53 is not activated. The breaker selector valve 48 remains in the operating state and the breaker selector valve 48 is located at the blade side position, and the spare valve 19 is switched based on the switching of the first and second pilot switching valves 26, 33. Hydraulic oil from the main hydraulic pump P m is supplied to the tilt hydraulic cylinder 12 or the angle hydraulic cylinders 11 L and 11 R via the breaker selector valve 48 as needed to change the attitude of the blade 10. In this case, the control state is the same as that of the first male embodiment.

Next, a case will be described in which the pedal 49 is depressed forward or backward and any of the corresponding breaker operation switches 50, 51 is operated. When the operation switch 50 or 51 is operated and an operation signal is input to the breaker control unit 52, the break force control unit 52 performs the first and third pilot switching valves 26, 5 based on the operation signal. The switching control of 3 is performed, but at this time, the second pilot switching valve 26 is maintained in a state of being switched to the tilt side in a non-operating state. Then, the breaker controller 52 outputs an operation command to the solenoid 53 a of the third pilot switching valve 53 based on the signal, and the third pilot switching valve 53 is switched based on this. The pilot pressure oil supply oil passage 48 a of the selector valve 48 opens, the pilot pressure oil from the sub-hydraulic pump Ps is supplied, and the breaker selector valve 48 becomes the breaker hydraulic cylinder 47 side. Switch to position.

Further, the breaker control unit 52 outputs an operation command to the first pilot port switching valve 26, but the breaker control unit 52 is provided with a delay circuit 52a, An operation command is output to the port switching valve 26 when the delay time T has elapsed. Then, one of the solenoids 26 L and 26 R on the corresponding side operates to supply the pilot pressure oil from the sub hydraulic pump Ps to the operating hydraulic cylinder 25. Based on this, the spare valve 19 is opened to the corresponding side, and the hydraulic oil from the main hydraulic pump Ps is supplied to the breaker hydraulic cylinder 47, so that the breaker 46 performs the breaker work. Is set. Incidentally, the breaker hydraulic cylinder 47 is configured to supply pressure oil regardless of which side of the spare valve 19 is opened. It is set so that the breaker 46 will operate even if the user steps on 49 before or after. In the third embodiment, when the bucket at the tip of the arm 36 of the working unit 5 is removed, a breaker 46 for crushing is attached, and the breaker 46 is operated by the breaker 46, the operation control unit 4 What is necessary is just to depress the pedal 49 provided on the floor of the vehicle, and thereby the breaker 46 can be operated by the breaker 46. As described above, in the third embodiment, the blade 10 is deformed by operating one of the operation switches 28 to 31 and the pedal 49 is depressed. In this case, the breaker 46 can be operated by the breaker 46 attached to the tip of the working unit 5.In this case, the breaker selector valve 48 is replaced with the spare valve 19 for supplying hydraulic oil and the blade. 10 Provided between the blade selector valve 14 for deforming operation and the spare oil valve 19 and supply the hydraulic oil supplied from the spare valve 19 to the blade side or breaker based on the switching operation of the third pilot switching valve 53. Since the hydraulic cylinder 47 is switched to the hydraulic cylinder side, the pressure oil from one switching valve, the spare valve 19, can be selectively supplied to both the blade transformation and the breaker operation. It is for 1 9 of the co. As a result, the hydraulic oil can be supplied to a plurality of operating mechanisms without increasing the number of spare switching valves by increasing the size of the valve unit 18, thereby not only reducing the size and weight of the airframe, but also making these mechanisms possible. Both can be retrofitted, making it easy to operate.

Furthermore, in this case, the first and second pilot switching valves 26 and 33 are switched after the second and third pilot switching valves 33 and 53 are switched. Prior to the switching of the switching valves 24, 32, there was no problem that the hydraulic oil was inadvertently supplied to the hydraulic cylinders 11 L, 11 R, 12 and 47, and smooth operation was achieved. Operations can be performed.

In this case, a delay circuit 52a is provided in the breaker control unit 52 so that the signal output to the first pilot switching valve 26 is obtained from the signal output to the second and third pilot switching valves 33, 53. The delay can also be implemented by connecting a diode to the electrical wiring between the breaker controller and the first pilot switching valve. Further, a fourth ^ form shown in FIG. 22 may be adopted. In this device, the operation lever for changing the blade is configured to be operated by a joystick type operation lever 54. In this case, the left tilt and the right tilt posture are controlled by the operation lever 54. The left and right angles are controlled by the levers in the forward and backward directions of the levers 54, and a control signal corresponding to the blade controller 32 is output with each lever operation. It is set. The operation lever 54 is set to return to the neutral position in the non-operation state. In this case, the inclination amount of the blade 10 is set to change according to the operation amount of the operation lever 54. Have been.

According to the third aspect of the present invention, the auxiliary spool operating means and the pilot switching valve can be switched by operating the operation switch, thereby improving operability.

Industrial applicability

According to the first aspect of the present invention, the auxiliary spool operating means can be arranged in close proximity to the spool of the optional valve, and the spool operating means with no looseness can be performed.

In this case, according to the second aspect, a compact arrangement of the solenoid and the hydraulic cylinder means can be achieved.

According to the third aspect of the present invention, the auxiliary spool actuating means and the pie port switching valve can be switched by operating the operation switch, thereby improving operability. Further, in this device, the operation switch of the present invention can be provided on a grip portion of an operation lever for moving the blade up and down, whereby the blade can be moved up and down and tilted. Operation and angle operation can be combined into one operation lever, and operability is further improved.

Still further, according to the fourth aspect, a delay time can be set for the output of the switching command to the auxiliary spool operating means by operating the operation switch of the present invention. When the angle is switched, it is possible to avoid a problem that the auxiliary spool operating means is switched earlier than the pilot switching valve.

In addition, the pressure oil from one optional valve is In addition to the selector valve for the blade, it can be selectively supplied to the selector valve for the option. Further, according to claims 6 and 7, the option valve and the option selector valve of the present invention can be combined with the option hydraulic valve. When the operating tool is operated to operate the operating mechanism, the option valve can be controlled to be switched after the option selector valve is switched.

Claims

The scope of the claims :

1. On the lower traveling structure where the upper revolving structure is rotatably provided, a blade that moves up and down by operating the operating lever provided on the operation control unit is arranged, and from the hydraulic pump to a plurality of hydraulic actuators. A hydraulic excavator having a valve unit in which valves for centrally controlling the supply of pressure oil are provided, and spool operating means for operating each valve spool is provided on one side of the valve unit. In the above, the tilt hydraulic cylinder and the angle hydraulic cylinder are provided on the blade, and the tilt oil angle changing function is provided by supplying hydraulic oil to these hydraulic cylinders. The valve is a valve for supplying hydraulic oil to the hydraulic cylinder for tilt and angle, and the spool of the optional valve is operated. Hydraulic excavator auxiliary spool actuation means, arranged in between the Barubuyunitto being concentrated equipped with the spool actuating means for.

2. The auxiliary spool operating means according to claim 1, wherein the auxiliary spool operating means is an interlocking connection between a solenoid, a hydraulic cylinder means switched by the operation of the solenoid, and a cylinder load of a cylinder constituting the hydraulic cylinder means and a spool of an optional valve. A hydraulic excavator in which the solenoid and the hydraulic cylinder means are disposed between the spool operating means and the valve unit, and the connecting means is disposed in parallel with the spool operating means.

3. The blade selector for supplying hydraulic oil from the hydraulic pump to the tilt and angle hydraulic cylinders in the oil passage from the option valve switched by the auxiliary spool operating means according to claim 1 or 2. The blade selector valve is provided with a blade pilot switching valve for switching the blade selector valve, and the auxiliary spool operating means and the pilot switching valve are selectively switched between tilt and angle operations. A hydraulic excavator equipped with an operation switch that is operated to output commands.

4. The hydraulic excavator according to claim 3, wherein the operation switch is provided on a grip portion of an operation lever for moving the blade up and down.

5. The auxiliary sprocket according to claim 3 or 4, which is obtained by operating the operation switch. A hydraulic shovel in which a delay time is set in the output of the switching command to the operating means.

6. The pressure oil from the option valve according to claim 1, 2, 3, 4 or 5, is selectively switched to an option hydraulic operation mechanism different from tilt and angle operation and to the blade selector valve. A hydraulic shovel comprising: an optional selector valve for supplying; and a switching means for switching the optional selector valve based on operation of an operating tool.

7. In claim 6, the optional valve and the optional selector valve are configured such that when the operating tool is operated to operate the optional hydraulic operating mechanism, the optional valve is switched off after the optional selector knob is switched. Hydraulic excavators controlled to replace.