JP2549987Y2 - Pilot oil passage switching device for hydraulic system of construction machinery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application field] The present invention relates to a pilot oil path switching device for a hydraulic system of a construction machine, and particularly to a hydraulic system pilot for a boom, an arm, a bucket, and a turning mechanism of a hydraulic shovel. The present invention relates to a device suitable for an oil passage switching device.

(Prior art)

Hydraulic excavators among construction machines are provided with a boom drive cylinder, an arm drive cylinder, a bucket drive cylinder, and a hydraulic motor for rotating the movable swivel table. The pilot seat has a pair of left and right pilot valve devices (each having four pilot valves, each having four pilot valves) in order to switch the four pilot-type directional control valves (each having a pair of pilot operation parts) corresponding to the above. The pilot pressure discharge ports of these pilot valve devices are connected to pilot operation sections of the direction switching valve via pilot oil passages, respectively.

Here, since the correspondence between the operation direction of the operation lever and the operation direction of the hydraulic actuator is not standardized, the correspondence differs depending on the manufacturer, and
The three correspondences shown in FIGS. 3 to 5 (FIGS. 3, 4, and 23 of the embodiment of the present application) of JP-A-2-35120 are generally adopted.

Thus, when a user purchases a hydraulic excavator from a different manufacturer, the above correspondence is shared by switching the pilot oil passages from the pair of pilot valve devices to the four directional control valves.

Therefore, various oil path switching devices for switching the pilot oil path have been proposed. For example, JP-A-62-297
Japanese Patent Publication No. 513 and Japanese Utility Model Publication No. 1-24221 disclose an oil passage switching system including a selector valve or a switching valve for switching the connection state of a pilot oil passage between a pair of pilot valve devices and four directional switching valves. A device has been proposed, and JP-A-2-35120 discloses a device between a pair of pilot valve devices and four directional control valves.
There has been proposed a hydraulic excavator hydraulic circuit in which two two-position electromagnetic directional switching valves are provided, and the connection state of a pilot oil passage can be switched to at least three existing states via these electromagnetic directional switching valves.

In the former oil passage switching device, the very complicated structure 8
A port 2 position directional switching valve is required, and a large number of fittings and the like are required to connect the pilot oil passage to the switching valve, which increases the manufacturing cost and requires a large installation space.

In the latter hydraulic excavator hydraulic circuit, since six electromagnetic directional control valves are interposed, the production cost becomes remarkably expensive due to the electromagnetic directional switching, a large number of joint fittings, a large number of hydraulic hoses and hydraulic pipings, It requires a large installation space, increases the probability of failure, and lacks practicality.

Therefore, Japanese Utility Model Laid-Open Publication No. 3-130403 discloses a valve body incorporating four pilot valves of a pilot valve device.
A rotary block formed with two selection ports, a pump port, and a tank port, and is mounted on the lower end side of the valve body so as to be capable of being fixedly released, and has four switching ports, an inlet port, and an inlet bypass communicating therewith. Forming a port and an outlet port and an outlet bypass port communicating with the port,
Connecting the four switching ports to the four pilot oil passages of the two solenoid directional valves, connecting the inlet port to the pump,
There is described a pilot oil passage switching device in which an outlet port is connected to a tank and a rotary block is rotated by 90 degrees to switch connection states between four selection ports and four switching ports.

[Problems to be solved by the invention]

In the device disclosed in Japanese Utility Model Application Laid-Open No. 3-130403, the rotary block is brought into contact with the lower end surface of the valve body and fastened with fastening bolts, and since the configuration is such that a compression coil spring is mounted between the bolt head and the rotary block, It is difficult to ensure the sealing performance between the valve body and the rotary block,
Pilot oil pressure leaks easily occur. Further, the connection state between the four selection ports and the four switching ports can be switched only in two ways, and cannot be switched in three or more ways.

An object of the present invention is to prevent a pilot oil pressure leak in a pilot oil passage switching device of a hydraulic system of a construction machine, to enable switching of three or more pilot oil passages, and the like.

[Means for solving the problem]

According to a first aspect of the present invention, there is provided a pilot oil passage switching device for a hydraulic system of a construction machine, comprising: a plurality of hydraulic actuators; and a plurality of pilot-type directional switching valves respectively corresponding to the hydraulic actuators. At least one pilot valve device is provided in a hydraulic system of a construction machine having a directional control valve having a plurality of directional control valves and a plurality of pilot valve devices for selectively supplying pilot pressure to the directional control valves in accordance with the operation direction of an operation lever. With a plurality of pilot valves, a plurality of vertical pilot pressure discharge passages respectively corresponding to the plurality of pilot valves are formed at equal intervals in the circumferential direction at the lower part of the casing of the pilot valve device,
A port member having a plurality of pilot pressure discharge ports respectively connected to the plurality of pilot pressure discharge paths is fixed to a lower end side of the casing via a fastening member so as to be unlockable, and the port member is a casing in the unlocked state in the unlocked state. The plurality of pilot pressure discharge ports of the port member are respectively connected to a pilot operating portion of the direction switching valve via an oil passage including a hydraulic hose connected thereto. An annular oil chamber is formed between the fastening member and the port member, the upper and lower ends of the annular oil chamber facing the port member and the fastening member, respectively. The hydraulic oil is introduced into the annular oil chamber from a hydraulic pressure supply port formed in the port member. The port member is configured to be urged upward with respect to the fastening member. According to a second aspect of the present invention, there is provided a pilot oil passage switching device for a hydraulic system of a construction machine, comprising four hydraulic actuators and four pilot-type directional switching valves respectively corresponding to the hydraulic actuators, each of which comprises a pair of pilot operation units. Directional control valves, and two pilot valve devices for selectively supplying pilot pressure to these directional control valves in accordance with the operation direction of the operation lever, and two pilot valve devices each having four pilot valves. A pilot oil passage switching mechanism for switching a pilot oil passage that guides pilot pressure from eight pilot valves of the two pilot valve devices to eight pilot operation units of four directional switching valves in the hydraulic system of the construction machine. A body member fixedly disposed, a first port member rotatably mounted coaxially at one end of the body member, A second port member mounted rotatably coaxially on the other end of the member, and fastening means for securing releasably securing the first and second port member to the body member,
Four first inlet ports formed at one end of the body member at the same radial position at a phase angle of 90 °, and four first inlet ports formed in the first port member at the same radial position at a phase angle of 90 ° in the axial direction. Four second inlet ports, eight outlet ports axially transparent to the second port member at the same radial position at a phase angle of 45 °,
The four first oil ports and the first inlet port formed in the main body member are phase-shifted by 45 ° so that the two first inlet ports communicate with the first group of four outlet ports at 90 ° intervals. Connect the four second inlet ports of the state to the second
A pilot oil passage switching mechanism having four second oil passages formed in the main body member so as to communicate with the four outlet ports of the group, and four first inlet ports having hydraulic hoses connected thereto. And the four second inlet ports are connected to the other pilot valve device via an oil passage including a hydraulic hose connected thereto, and the first group of the first group is connected to the first pilot valve device. The four outlet ports are respectively connected to the four pilot operating parts of the two directional control valves via oil passages including hydraulic hoses connected to them, and
The four outlet ports of the group are each connected to the four pilot controls of the remaining two directional valves via an oil passage including a hydraulic hose connected to them.

[Action]

According to the first aspect of the present invention, there is provided a hydraulic oil pressure switching device for a construction machine, wherein a pilot pressure is supplied to the directional control valve by operating an operation lever of the pilot valve device to switch the directional control valve, and the hydraulic actuator is switched. Operate.

A plurality of pilot valves are incorporated in at least one of the plurality of pilot valve devices, and a direction of the pilot pressure discharge passage is switched through an oil passage including a pilot pressure discharge port of a port member and a hydraulic hose. Each is connected to the pilot operation part of the valve.

The plurality of pilot pressure discharge paths and the plurality of pilot pressure discharge ports are connected in a predetermined correspondence relationship, and the port member can be used with the port member fixed to the casing via a fastening member.

In order to change the predetermined correspondence, the fastening member is loosened to release the fixation of the port member, and then the port member is coaxially rotated with respect to the casing to thereby set the pilot pressure discharge path and the plurality of pilot pressures. What is necessary is to connect the discharge port to the discharge port in a correspondence different from the above-mentioned correspondence, and then fix the port member to the casing via the fastening means.

Since the hydraulic hose is connected to the pilot pressure discharge port of the port member, when the port member is rotated as described above, it can be rotated while the hydraulic hose is connected. Further, since the plurality of pilot pressure discharge paths of the casing are formed at equal intervals in the circumferential direction, the connection state between the pilot pressure discharge path and the pilot pressure discharge port can be switched by rotating the port member as described above. I can do it.

In the use state, the oil pressure is supplied to the annular oil chamber, so that the port member is urged upward with respect to the fastening member by the oil pressure, whereby the sealing property between the casing of the pilot valve device and the port member can be secured. . In addition, in the non-use state, no oil pressure is supplied to the annular oil chamber, so that the resistance when rotating the port member does not increase.

In the pilot oil passage switching device for a hydraulic system of a construction machine according to the second aspect, a pilot pressure is supplied to the directional switching valve by operating an operation lever of the pilot valve device, and the directional switching valve is switched to switch the hydraulic actuator. Operate.

The pilot oil passage switching mechanism will be described. Basically, the four first inlet ports of the main body member and the four second inlet ports of the first port member are arranged at a phase angle of 45 °, and these eight first The first and second inlet ports and the eight outlet ports are set to correspond in the same phase, and the first port member and the second port member are used with the first port member and the second port member fixed to the main body member by fastening means.

At this time, the four first inlet ports connected to one of the pilot valve devices are connected to the first group of four outlet ports via the four first oil passages in the main body member (these are connected to the two directional control valves). Are connected to the other pilot valve device, and the four second inlet ports are connected to the other pilot valve device through four second oil passages in the main body member. Connected to the two directional control valves)
Connected to each other.

By loosening the fastening means, turning the first port member 90 ° clockwise or counterclockwise with respect to the main body member, and then fixing the first port member again with the fastening means, the connection state of the pilot oil passage can be switched to a plurality of positions. I can do it.

Also, the connection state of the pilot oil passage is switched to a plurality of positions by loosening the fastening means, rotating the second port member 45 ° clockwise or counterclockwise with respect to the main body member, and then fixing the second port member again with the fastening means. I can do it. Therefore, by combining the rotation of the first port member and the rotation of the second port member, the pilot oil passage can be switched to at least three connection states.

[Effect of the invention]

According to the pilot oil passage switching device for a hydraulic system of a construction machine according to the first aspect, a port member having a plurality of pilot pressure discharge ports is fixed to a lower end side of the casing via a fastening member so as to be releasable. Since the pilot pressure discharge port is connected to the pilot operating part of the directional control valve via the oil passage including the hydraulic hose connected to it, the pilot oil passage switching device has a small number of parts and a very simple configuration and is compact. It can be arranged in a small space below the pilot valve device, the production cost is very low, and in use, oil pressure is supplied to the annular oil chamber,
The port member is urged upward by the hydraulic pressure with respect to the fastening member, whereby the sealing property between the casing of the pilot valve device and the port member can be secured. Moreover, in the non-use state, no oil pressure is supplied to the annular oil chamber,
There is no increase in resistance when rotating the port member.

According to the hydraulic fluid pilot oil passage switching device for a construction machine according to the second aspect, the pilot oil passage switching mechanism has four first inlet ports, four first oil passages, and four second oil passages. A body member having a main body member, a first port member having four second inlet ports connected to the other pilot valve device and rotatably mounted on the main body member coaxially, and a body member having eight outlet ports. The pilot oil passage switching device has a small number of members and is relatively simple because the second port member is rotatably mounted on the second port member and the fastening means. In spite of the configuration, effects such as being able to switch the connection state of the pilot oil passage in three or more ways and being able to be manufactured relatively inexpensively are obtained.

〔Example〕

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

<First Embodiment> Referring to FIGS. 1 to 11, a revolving backhoe 1 as a construction machine will be described with reference to FIG. 1. A traveling machine base 3 having a pair of right and left crawler traveling devices 2 is mounted around a vertical axis. A turntable 4 is provided rotatably on the turntable 4, and a control unit 5 is provided on the turntable 4.
An excavator 6 is provided at the front of.

The excavator 6 is provided with a boom 7 attached to the swivel table 4 so as to be able to swing up and down, an arm 8 attached to the tip of the boom 7 so as to be able to swing, and a swingable attachment to the tip of the arm 8. Bucket 9, a boom cylinder 10 for swingingly driving the boom 7, and an arm cylinder 11 for swingingly driving the arm 8.
And a bucket cylinder 12 that swings and drives the bucket 9.
And a turning hydraulic motor 13 for driving the turning table 4 to turn.

A first operation lever 14 and a second operation lever 15 for operating the excavator 6 are provided on the left and right sides of the driver's seat of the control unit 5, respectively. The first operation lever 14 is shown in FIG. 2 (a). Operable in four operation directions A to D, and the second operation lever 15
Can be operated in four operation directions E to H shown in FIG. 2 (b). The correspondence (operation / function correspondence mode) between the eight operation directions A to H and the operation of each member of the excavator 6 is the third.
This is as shown in FIG. 4 or FIG.

Next, the hydraulic system of the excavator 6 will be described with reference to FIG.

Pilot type directional control valve 20 for switching the oil path to boom cylinder 10, pilot type directional valve 21 for switching the oil path to arm cylinder 11, and bucket cylinder 12
A pilot-type directional switching valve 22 for switching an oil path to the hydraulic motor for turning is provided with a pilot-type directional switching valve 23 for switching an oil path to the hydraulic motor for turning. They are connected in series to the passage 25 and are also connected to the drain oil passage 26, respectively.

A first pilot valve device 16 including the first operation lever 14
And a second pilot valve device 17 including a second operation lever 15, and the first pilot valve device 16 is provided with a first operation lever
It has four pilot valves 16A to 16D which are operated at 14 and correspond to the four operation directions A to D, and the second pilot valve device 17 is operated by the second operation lever 15 and corresponds to the four operation directions E to H. It has four pilot valves 17E to 17H, and the four pilot pressure discharge passages 16a to 16d of the first pilot valve device 16 are connected to the direction switching valves 21 and 21 via pilot oil passage switching mechanisms 18 and oil passages 27 to 30 described later. 23 pilot operation parts 21a ・ 21b ・ 23a ・ 2
3b, the operating direction E of the second pilot valve device 17
The pilot pressure discharge passages 17e and 17f of the pilot valves 17E and 17F corresponding to F are connected to the pilot operating portions 20a and 20b of the directional control valve 20.
And the pilot pressure discharge passage 17g of the pilot valve 17G / 17H corresponding to the operation direction G / H as shown in FIG.
17h is connected to the pilot operation parts 22a and 22b of the direction switching valve 22 as shown in the figure.

A hydraulic pressure is supplied to the first pilot valve device 16 from a hydraulic pump 19 for generating pilot pressure via an oil passage 31, a pilot oil passage switching mechanism 18, and an oil passage 32.
The 16 drain oil passages 33 are connected to the oil tank via the pilot oil passage switching mechanism 18 and the drain oil passage 34.

The second pilot valve device 17 is supplied with hydraulic pressure via oil passages 31 and 35, and its drain oil passage 36 is connected to an oil tank.

When the pilot oil passage switching mechanism 18 is in the state shown in FIG. 5, the operation / function corresponding mode shown in FIG. 3 is set. For example, when the first operation lever 14 is tilted in the operation direction A, the pilot valve
The pilot pressure is supplied to the pilot pressure discharge passage 16a of 16A, and the pilot pressure is supplied to the pilot operation portion 23b of the direction switching valve 23 via the pilot oil passage switching mechanism 18, so that the hydraulic motor 13 operates counterclockwise and turns. When the table 4 turns left and the first operation lever 14 is tilted to the operation direction B, the hydraulic motor
13 operates clockwise, and the swivel 4 turns right.

By the way, the manufacturer A of the revolving backhoe 1
The operation / function correspondence mode shown in the figure is adopted, and Company B adopts the operation / function correspondence mode shown in FIG. 4. However, since there is a demand that the user wants to use one of the modes unifiedly, the pilot The oil passage switching mechanism 18 can switch the mode from the mode of FIG. 3 to the mode of FIG. 4 or vice versa.

Next, the first pilot valve device 16 and the pilot oil passage switching mechanism 18 mounted on the lower end thereof will be described with reference to FIGS.
This will be described with reference to FIG.

As shown in FIG. 6, the first pilot valve device 16 is the same as an existing one, and four pilot valves 16A to 16D provided in a casing 40 are provided with a first operating lever 14A.
Is selectively opened in the operation directions A to D. First of spools 41 of each pilot valve 16A to 16D
Drain oil passage 33 and pilot pressure discharge passage 1 by land 41a
The area between 6a to 16d is opened and closed, and the second land 4
1b opens and closes the oil passage 32 and the pilot pressure discharge passages 16a to 16d. Reference numeral 42 denotes a labyrinth seal shaft,
Reference numeral 43 denotes an annular groove communicating with the drain oil passage 33.

As shown in FIGS. 6 to 8, a lower casing 44 is fixed to the lower end of the casing 40 with two bolts (not shown), and four pilots are provided in the lower part of the casing 40 and in the lower casing 44. Pilot pressure discharge path for valves 16A to 16D
16a to 16d are vertically formed at the same radial position at 90 ° intervals in the circumferential direction, and an upstream portion 32a of the oil passage 32 is formed between the pilot pressure discharge passages 16b and 16c.

Further, a branch path 32b branched from the upstream section 32a in the lower casing 44 is connected to an opening 32c opened on the lower surface in the middle of the pilot pressure discharge paths 16b and 16d.

A concentric circular receiving hole 46 is recessed from the lower surface of the lower casing 44 at a height of about 3/4 on the lower side, and a circular port member 47 is received in the receiving hole 46.
A fastening member 58 is screwed into the center of the lower casing 44 through the center of the lower casing 44, and the port member 47 is fixed to the upper end surface of the receiving hole 46 of the lower casing 44 by the fastening member 58 so as to be releasably abutted. Have been. The port member 47 has pilot pressure discharge ports 30a, 29a, 27a, and 28a connected to the pilot pressure discharge paths 16a to 16d so as to face each other, and are formed vertically at the same radial position at 90 ° intervals in the circumferential direction. With the upstream part 32a
The hydraulic supply port 31a and the drain port 34a that is 180 ° circumferentially shifted with respect to the hydraulic supply port 31a are formed in an upright direction. Reference numeral 49 denotes a seal member.

In the fastening member 58, the lower large diameter portion 58a has a middle step middle diameter portion 58b and an upper end small diameter screw portion 58c, and the large diameter portion 58a and the middle diameter portion 58b are located at the center of the port member 47. Oil-tightly slidably inserted into the large-diameter hole 47a and the medium-diameter hole 47b, and the small-diameter screw portion 58c.
Is screwed into the center of the lower casing 44.

A disc spring 60 is mounted on the annular oil chamber 59 on the upper end side of the large-diameter portion 58a, and the annular oil chamber 59 is connected to the hydraulic pressure supply port 31a via an oil passage (not shown). In addition, the concave portion 61 is the small hole 6
2 communicates with the annular groove 43 to introduce the drain oil.

Further, an annular drain oil passage is provided on the outer peripheral portion of the upper end of the port member 47.
33A is formed so as to communicate with the drain oil passage 33, and the drain port 34a is communicated with the drain oil passage 33A. Further, in order to rotate the port member 47, a vertical hole 63 is formed in the vicinity of one side of the port member 47 as shown in FIGS.
A movable shaft 64 is mounted on the 63 so as to be able to move up and down. The movable shaft 64 is urged upward by a compression coil spring 65, the spring 65 is received by a spring holder 66, and the movable shaft 64 has a handle extending radially outward. The handle 67 is fixed, and the handle 67 can be moved in the circumferential direction within a notch 68 over a quarter of the circumference of the cylindrical wall portion 44a, and engagement portions 69 and 70 are formed at both ends of the notch 68. By moving the handle 67 in the circumferential direction, the port member 47 can be turned 90 ° about the fastening member 58.

In the state of FIG. 7, the operation / function corresponding mode of FIG. 3 is set, and in the state of 90 ° rotation, the mode of FIG. 4 is set.

In the use state, the hydraulic pressure is introduced into the annular oil chamber 59, so that the hydraulic pressure and the spring force of the disc spring 60 allow the port member 47.
Is strongly pressed against the upper end surface of the accommodation hole 46, so that the sealing surface
47c sealing performance is ensured. On the other hand, when the mode is switched, the hydraulic pump 24 is stopped and the hydraulic pressure is not introduced into the annular oil chamber 59, so that the port member 47 is only pressed by the spring force of the disc spring 60. The mode can be switched by rotating the port member 47 with a relatively small torque. Since it is not necessary to switch the connection between the hydraulic supply port 31a and the oil passage 32 and the connection between the drain port 34a and the oil passage 33, the hydraulic supply port 31a and the drain are connected to the lower casing 44 as shown in FIG. A port 34a may be formed.

The pilot pressure discharge ports 27a to 30a of the port member 47 are connected to oil path hoses forming the oil paths 27 to 30, respectively, the hydraulic supply port 31a is connected to a hydraulic hose forming the oil path 31, and the drain port 34a Is connected to a hydraulic hose constituting a drain oil passage.

In the first pilot valve device 16 and the pilot oil passage switching mechanism 18, when the port member 47 is fixed at the position shown in FIG. 8, the oil pressure is supplied from the oil passage 31 to the hydraulic supply port 31a, the upstream portion 32a, and the oil passage 32. Is supplied, and the drain oil flows from the drain oil passage 33 to the drain oil passage 34 via the drain oil passage 33A and the drain port 34a. At this time, the pilot oil passage switching mechanism
Reference numeral 18 denotes the circuit schematically shown in FIG. 5, and the operation / function corresponding mode is as shown in FIG.

On the other hand, when the fastening member 58 is loosened and the port member 47 is rotated 90 ° in the direction of the arrow X in FIGS. 5 and 8 and then the fastening member 58 is fastened, the pilot pressure discharge passages 16a, 16b. 16
Since c and 16d are connected to the pilot pressure discharge ports 28a, 27a, 30a, and 29a, respectively, the operation / function corresponding mode shown in FIG. 4 is established. However, in this case, the hydraulic supply port 31a has the opening 3
2c and a branch passage 32b, and is connected to the hydraulic supply passage 32, and the drain port 34a is connected to the drain oil passage 33 through a drain oil passage 33A.
Will be connected.

According to the embodiment described above, the pilot oil passage switching mechanism 18 can be constituted mainly by the port member 47 attached to the lower ends of the casings 40 and 44 of the first pilot valve device 16, so that the structure is simple and small. Therefore, the installation space can be reduced, the manufacturing cost can be reduced, and the length and the number of hydraulic hoses do not increase, and the number of fittings for oil passages does not increase. In addition, the sealing performance of the contact portion between the port member 47 and the casing 44 can be ensured.

<Second Embodiment> See FIGS. 12 to 24 This embodiment is provided with a pilot oil passage switching mechanism 80 which is a further development of the pilot oil passage switching mechanism 18.
The same components as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

First, the pilot oil passage switching mechanism 80 will be described. As shown in FIGS. 13 to 16, a main body member 81 fixed to the swivel base 4 includes a laterally substantially cylindrical shaft member 82,
An annular member 83 is externally fitted and fixed to this.
An annular groove 84 is formed outside the shaft member 81 at the left end of the 83,
A first port member 85 is coaxially and rotatably mounted in the annular groove 84, and is locked by a flange 82a of the shaft member 82. At the right end of the annular member 83, an annular groove 86 is formed outside the shaft member 82, and a second port member 87 is coaxially and rotatably mounted in the annular groove 86. A locking plate 89 is fastened by a fastening bolt 88 screwed to the center portion, and the first port member 85 and the second port member 87 can be fixed and released by the locking plate 89 to the shaft member 82 and the annular member 82. It is fixed to. Four first inlet ports 90 are provided at the left end of the shaft member 82.
E to 90H are formed around the axis at a phase angle of 90 ° toward the axial direction at the same radial position, and the first port member 85 is provided with four second inlet ports 91A to 91D in phase around the axis. The first inlet port and the second inlet port are arranged at 45 ° intervals in the state shown in the drawing in the axial direction at the same radial position at 90 ° intervals. In this state, the second port member 87 has eight outlet ports.
92a to 92h are provided in the same radial position around the axis at a phase angle of 45 ° at the same radial position in the axial direction.
The outlet ports 92e to 92h at an interval of four are four first inlet ports 90.
In the circumferential position corresponding to E to 90H, the remaining four 90 ° -spaced outlet ports 92a to 92d of the second group are at circumferential positions opposed to the four second inlet ports 91A to 91D. I have.

Further, the shaft member 82 and the annular member 83 are formed with four crank-shaped first oil passages 93 connecting the four first inlet ports 90E to 90H to the first group of four outlet ports 92e to 92h, respectively. The annular member 83 has four second inlet ports 91A to 91D.
Four straight second oil passages 94 are formed to connect to the four outlet ports 92a to 92d of the group, respectively.

Pilot pressure discharge passages 17e to 17h composed of hydraulic hoses are respectively connected to the four first inlet ports 90E to 90H as shown in FIG. 12, and hydraulic hoses are connected to the four second inlet ports 91A to 91D. The pilot pressure discharge passages 16a to 16d
Each is connected as shown in the figure. Hydraulic pressures 93 to 96 composed of hydraulic hoses are respectively connected to the four outlet ports 92e to 92h of the first group as shown in FIG. 12, and hydraulic pressures are connected to the four outlet ports 92a to 92d of the second group. Oil passages 97 to 100 composed of hoses are connected as shown in FIG.
In addition, as shown in FIG. 12, the first and second pilot valve devices
Oil pressure is supplied to the oil pumps 16 and 17 from the hydraulic pump 19 through an oil passage 32A, and the drain oil of the first and second pilot valve devices 16 and 17 flows to the oil tank through an oil passage 33A.

The operation of the above-described pilot oil passage switching device will be described.

The connection states of the oil passages and the ports in the states of FIGS. 12 to 16 are as shown in FIG. 17 and Table 1, and the operation / function corresponding mode of FIG. 3 is realized.

Next, after loosening the fastening bolt 88, the first port member 85 is counterclockwise viewed from the left in FIG. 13 (arrow Y in FIG. 12).
18) and the fastening bolt 88 is fastened again, the state is as shown in FIG. 18, the connection state of the oil passage is as shown in Table 2, and the operation / function corresponding mode of FIG. 4 is realized. You.

Next, in the state shown in FIG. 18 and Table 2, the fastening bolt
After loosening 88, the second port member 87 is turned 45 ° in the counterclockwise direction (the direction of arrow Z in FIG. 12) when viewed from the right in FIG. 13 and the fastening bolt 88 is fastened again. 19, the connection state of the oil passage is as shown in Table 3, and the operation / function corresponding mode shown in FIG. 20 is realized.

Next, a modified example of the pilot oil passage switching mechanism 80 will be described with reference to FIGS. However, the same reference numerals are given to the same components as described above, and the description will be omitted.

The main body member of the pilot oil passage switching mechanism 80A is constituted by an integral main body member 81A, and a first disc-shaped port 85A is coaxially rotatably mounted in a circular concave portion on the left end side of the main body member 81A. A disc-shaped second port member 87A is coaxially rotatably mounted on the right end of the member 81A so as to be in contact with the first port member 85A, and the first fastening bolt 8 is inserted through the center of the first port member 85A.
8A is screwed into the center of the main body member 81A, and the first port member 8
5A can be released by the first fastening bolt 88A.
1A, and the second port member 87A is fixed to the second fastening bolt 88B.
Thus, it is fixed to the main body member 81A so that the fixing can be released.

The four first inlet ports 90E-
90H is formed, and four second inlet ports 91A to 91D are formed at one end of the first port member 85A.
A has eight outlet ports 92a to 92h formed therein, and is connected to an oil passage similarly to the pilot oil passage switching mechanism 80.
The same function as described above can be obtained by the pilot oil passage switching mechanism 80A.

According to the pilot oil passage switching device 80 / 80A of the second embodiment, the first port members 85/85 remain connected to the hydraulic hose.
A Since the pilot oil passage switching mechanism 80 / 80A that switches the connection of the oil passage by rotating the right second port member 87 / 87A is used, the structure becomes simple and small with a small number of members, and the space is reduced. Not only can it be installed and manufactured inexpensively, but also can be freely switched over in three modes of operation and functions, and is excellent in versatility and practicality.

[Brief description of the drawings]

1 shows an embodiment of the present invention. FIG. 1 is a side view of a revolving backhoe, and FIGS. 2 (a) and 2 (b) show operating directions of a first operating lever and a second operating lever, respectively. Illustration of,
3 and 4 are explanatory diagrams of operation / function corresponding modes, respectively.
FIG. 5 is a configuration diagram of a hydraulic system, FIG. 6 is a sectional view of a first pilot valve device and a pilot oil passage switching mechanism, and FIG.
FIG. VII view, FIG. 8 is a schematic exploded perspective view of the lower casing and the port member, FIG. 9 is a schematic perspective view of the port member, FIG.
FIG. 10 is a cross-sectional view of the structure near the handle, FIG. 11 is a cross-sectional view of the lower casing and the port member of the modification, FIGS.
FIG. 24 relates to the second embodiment, FIG. 12 is a configuration diagram of a hydraulic system, FIG. 13 is a sectional view of a pilot oil passage switching mechanism, and FIG.
FIG. 13 is a view as viewed in the direction of arrow XIV in FIG. 13, FIG. 15 is a view as viewed in the direction of arrow XV in FIG.
The figure is a partial cross-sectional view of the pilot oil passage switching mechanism.
FIG. 19 is a schematic perspective view of the pilot oil passage switching mechanism in each state, FIG. 20 is an explanatory view of the operation / function corresponding mode, and FIG.
FIGS. 21 to 24 are diagrams corresponding to FIGS. 13 to 16, respectively, according to modifications. 1 ... Revolving backhoe, 10 ... Boom cylinder, 11
…… Cylinder for arm, 12 …… Cylinder for bucket, 13
…… Hydraulic motor, 14 ・ 15… Operation lever, 16 ・ 17 …… Pilot valve device, 16A-16D ・ 17E-17H …… Pilot valve, 16a-16d ・ 17e-17h …… Pilot pressure discharge path, 18…
... Pilot oil passage switching mechanism, 20 to 23 ... Directional switching valve, 20
a to 23b: Pilot operation unit, 27 to 30: Oil passage, 27a to 3
0a: Pilot pressure discharge port, 40: Casing, 44
... lower casing, 47 ... port member, 58 ... fastening member, 59 ... annular oil chamber, 60 disc spring, 80 / 80A ... pilot oil passage switching mechanism, 81 / 81A ... body member, 85・ 85A…
... First port member, 87 / 87A ... Second port member, 88.8
8A / 88B: fastening bolt, 90E-90H: first inlet port, 91A-91D: second inlet port, 92a-92h ... outlet port, 94-100: oil passage.

Claims (2)

(57) [Scope of request for utility model registration] 1. A plurality of hydraulic actuators, a plurality of pilot-type directional switching valves respectively corresponding to the hydraulic actuators, each having a pair of pilot operating portions, and an operation lever connected to the directional switching valves. In a hydraulic system of a construction machine having a plurality of pilot valve devices for selectively supplying a pilot pressure according to an operation direction, at least one pilot valve device includes a plurality of pilot valves and a casing of the pilot valve device. A plurality of vertical pilot pressure discharge passages respectively corresponding to the plurality of pilot valves are formed at equal intervals in the circumferential direction at a lower portion of the casing, and the lower end side of the casing is connected to the plurality of pilot pressure discharge passages, respectively. A port member having a plurality of pilot pressure discharge ports is releasably fixed via a fastening member, and a port portion is provided. Is disposed so as to be rotatable coaxially with respect to the casing in the unlocked state, and the plurality of pilot pressure discharge ports of the port member are connected to the pilot of the direction switching valve via an oil passage including a hydraulic hose connected thereto. An annular oil chamber is formed between the fastening member and the port member, the upper and lower ends of the annular oil chamber facing the port member and the fastening member, respectively. A pilot oil passage switching device for a hydraulic system of a construction machine, characterized in that the port member is urged upward with respect to the fastening member by the hydraulic pressure introduced into the pilot member. 2. Four hydraulic actuators and four pilot-type directional control valves respectively corresponding to these hydraulic actuators, each having a pair of pilot operating parts.
Construction comprising two directional control valves and two pilot valve devices for selectively supplying pilot pressure to these directional control valves in accordance with the operation direction of an operation lever, each pilot valve device having four pilot valves. In a hydraulic system of a machine, a pilot oil passage switching mechanism for switching a pilot oil passage that guides pilot pressure from eight pilot valves of the two pilot valve devices to eight pilot operation parts of four directional switching valves, , A first port member rotatably mounted coaxially at one end of the main body member, and a second port member rotatably mounted coaxially at the other end of the main body member. A port member, fastening means for releasably fixing the first and second port members to the main body member, and a phase angle at one end of the main body member.
Four first inlet ports formed at the same radial position at 90 ° intervals, four second inlet ports provided at the same radial position at 90 ° phase angle axially through the first port member, and Eight outlet ports and four first inlet ports, which are provided in the two-port member in the axial direction at the same radial position at a phase angle of 45 °, and the four first inlet ports are 90 °.
Four first oil passages formed in the main body member and four second inlet ports in a state of being phase-shifted by 45 ° with respect to the first inlet ports so as to communicate with the first group of four outlet ports at intervals. A pilot oil passage switching mechanism having four second oil passages formed in the main body member so as to communicate with the remaining second group of four outlet ports at 90 ° intervals; The ports are connected to one pilot valve device via an oil passage including a hydraulic hose connected thereto, and the four second inlet ports are connected to the other pilot valve via an oil passage including a hydraulic hose connected thereto. The four outlet ports of the first group are respectively connected to the four pilot operating parts of the two directional control valves via oil passages including hydraulic hoses connected to them, and the four outlet ports of the second group are connected to the four outlet ports of the first group. Outlet ports are for oil connected to them Hydraulic system pilot oil passage switching device for a construction machine, characterized in that via the oil passage are respectively connected to the four pilot operating unit of the remaining two directional control valve comprising a hose.