JP2003278710A - Pilot operating device of direction changeover valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve responsiveness in changeover operation of a direction changeover valve by improving responsiveness in pressure regulation of a pressure reducing valve not by a software process, and by equipping with warm up function, in this pilot operating device of the direction changeover valve. <P>SOLUTION: Primary ports of solenoid proportional pressure reducing valves 3a, 3b are connected with a discharge passage 6 of a pilot hydraulic pump 5 via first ducts 4a, 4b, and secondary ports of the solenoid proportional pressure reducing valves 3a, 3b are connected with pressure receiving parts 52a, 52b of the direction changeover valve 50 via second ducts 7a, 7b. Third ducts 12a, 12b are provided for connecting the discharge passage 6 and the second ducts 7a, 7b respectively, and check valves 13a, 13b and throttles 14a, 14b for permitting flowing in of pressure oil from the discharge passage 6 into the second ducts 7a, 7b and preventing flow of the pressure oil from the second ducts 7a, 7b into the discharge passage 6 are arranged on the third ducts 12a, 12b. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a directional control valve pilot operating device provided in a hydraulic drive circuit of a construction machine such as a hydraulic excavator and drivingly controlling the directional control valve.

[0002]

2. Description of the Related Art As a conventional pilot operating device for switching a directional control valve, a portion for generating pilot pressure in accordance with the operation of an operating lever (hereinafter referred to as a pilot pressure generating portion) is an electric operating lever device, controller,
It is generally known that an electric system including an electromagnetic proportional pressure reducing valve and a hydraulic mechanical system including a hydraulic operation lever device that mechanically drives the pressure reducing valve with an operation lever are used.

An example of a pilot operating device in which the pilot pressure generating portion is an electric system is disclosed in, for example, Japanese Patent Laid-Open No. 5-195.
546, JP-A-8-210305 and JP-2
000-205204, and as the pilot operating device in which the pilot pressure generating section is constituted by a hydraulic mechanical system, for example, those described in Japanese Utility Model Laid-Open No. 5-10803 and Japanese Patent Laid-Open No. 8-120709. is there.

Japanese Unexamined Patent Publication Nos. 5-195546 and 8
In the pilot operating device described in JP-A-210305 and JP-A-2000-205204 in which the pilot pressure generating unit is configured by an electric system, the electromagnetic proportional force is proportional to the input command amount from the electric operating lever device as described below. When controlling the drive of the pressure reducing valve and switching operation of the direction switching valve, software correction is applied to the drive signal of the electromagnetic proportional pressure reducing valve according to the input status of the operating lever in order to improve the responsiveness of the switching operation of the direction switching valve. Is proposed to do.

JP-A-5-195546 [Patent Document 1] Japanese Patent Application Laid-Open No. 5-195546 This is related to the improvement of the drive control method of the electromagnetic proportional pressure reducing valve, and in response to the drive current of the proportional solenoid of the electromagnetic proportional pressure reducing valve, the input speed of the operating lever is specified in the control program. The output is corrected according to.

[Patent Document 1] Japanese Patent Application Laid-Open No. 8-210305 The standby pressure is applied to the output pressure of the electromagnetic proportional pressure reducing valve that acts on both ends of the spool of the directional control valve so that the non-operating side of both ends of the spool of the directional control valve changes from the input state of the operating lever. The output pressure of the electromagnetic proportional decompression valve relating to is reduced.

[Patent Document 1] Japanese Unexamined Patent Publication No. 2000-205204 At the same time as the output pressure of the electromagnetic proportional pressure reducing valve is applied to both ends of the spool of the directional control valve, an electric on / off valve is provided and the on / off valve is switched according to the input state of the operating lever. , Assist the flow rate of the electromagnetic proportional pressure reducing valve on the operating side.

Japanese Utility Model Laid-Open No. 5-10803 and Japanese Unexamined Patent Publication No. 8-
In the pilot operating device in which the pilot pressure generating unit described in Japanese Patent Publication No. 120709 is composed of a hydraulic mechanical system, the viscous resistance of the working fluid is reduced for the purpose of improving the responsiveness of the switching operation of the directional control valve, as described below. , A method of improving responsiveness by warming up the pilot hydraulic circuit has been proposed.

[Patent Document 1] Japanese Utility Model Laid-Open No. 5-10803 An electromagnetic switching valve for disabling the primary pressure to the pressure reducing valve of the hydraulic pilot device is provided, and the primary pressure is throttled when the primary pressure cannot be supplied (that is, when the operation lever device cannot be operated). Is connected to the second conduit of the pressure reducing valve to circulate the working fluid that has generated heat at the throttle.

Japanese Unexamined Patent Publication No. 8-120709 discloses a warm-up circuit having a throttle like that of Japanese Utility Model Laid-Open No. 5-10803. The warm-up circuit provided with this throttle is formed through a lock valve that is generally provided in a hydraulic excavator as a safety device that disables the operation lever device.

[0011]

However, the above-mentioned prior art has the following problems.

In a pilot operating device in which the pilot pressure generator is composed of an electric system or a hydraulic mechanical system, the problem that the switching speed of the directional control valve spool is slow when driving the directional control valve is due to the operation of the pressure reducing valve, that is, the secondary pressure. It is considered that this is largely due to the slow pressure regulation control and the influence of the viscous resistance of the working fluid.

The delay in adjusting the pressure of the pressure reducing valve refers to the delay in rising of the secondary pressure. Since the pressure reducing valve performs mechanical pressure feedback of the secondary pressure, the secondary pressure is equal to the target pressure. When the opening of the pressure reducing valve spool is large, the opening connecting the primary pressure port and the secondary pressure port of the pressure reducing valve spool is fully opened, and the pressure increase of the secondary pressure starts. At this time, the directional control valve spool starts to move, and a flow rate commensurate with the volume change accompanying the movement is required. However, the secondary pressure rising toward the target pressure means that the primary pressure and the secondary pressure of the decompression valve spool increase. The pressure difference from the pressure is eliminated, that is, the flow rate from the primary pressure side to the secondary pressure side is reduced and limited. Furthermore, the volume of the pilot pressure chamber (that is, the second conduit) increases with the movement of the directional control valve, and the pressure rise slows down, and the pilot flow rate required for rapid movement of the directional control valve spool can be secured by the pressure reducing valve. As a result, a sufficient response cannot be obtained.

Further, when the pilot pressure generator is constructed by an electric system, there is a further delay such as a dead time associated with the excitation of the driving proportional solenoid of the voltage proportional pressure reducing valve.

Japanese Unexamined Patent Publication Nos. 5-195546 and 8
In the pilot operating device in which the pilot pressure generating unit is configured by an electric system as described in JP-A-210305 and JP-A-2000-205204, an input state is determined by an operation lever signal and correction driving is performed, and therefore a controller is used. After that, follow-up control and program control are performed, and it is difficult to secure sufficient responsiveness. Further, when dealing with a large flow type directional control valve, it is necessary to upsize hydraulic equipment such as a pressure reducing valve in order to secure a further pilot flow rate.

Japanese Utility Model Laid-Open No. 5-10803 and Japanese Unexamined Patent Publication No. 8-
In the pilot operating device in which the pilot pressure generating unit is configured by the hydraulic mechanical system as described in Japanese Patent No. 120709, although improvement due to the warm-up effect of the pilot hydraulic circuit can be expected, as described above, due to insufficient pilot flow rate, it is still sufficient. It is not possible to secure responsiveness.

An object of the present invention is to improve the responsiveness of the pressure reducing valve for adjusting the pressure and to provide the warming function without depending on the software processing, thereby improving the responsiveness of the switching operation of the directional control valve. It is an object of the present invention to provide a pilot operation device for a directional control valve.

[0018]

(1) In order to achieve the above object, the present invention provides a first pipe line through which the discharge pressure of a hydraulic pump defined by a relief valve is guided as a primary pressure, and an operating lever device. Has a pressure reducing valve for reducing the primary pressure to generate a secondary pressure in accordance with the input command amount from the pressure reducing valve, and a second pipe line for outputting the secondary pressure of the pressure reducing valve. A pilot operating device for a directional control valve, which is connected to a pressure receiving portion located at an end of a spool valve body of the directional control valve and which switches and operates the directional control valve by the secondary pressure of the pressure reducing valve, wherein the first conduit and the second channel are provided. A third pipeline connecting to the pipeline is provided, and the inflow from the first pipeline to the second pipeline is permitted on the third pipeline, and the second pipeline
A check valve for blocking the flow from the pipeline to the first pipeline and a throttle are arranged.

Immediately after the operation lever device is input, the third pipe line connecting the first pipe line and the second pipe line is provided and the check valve and the throttle are arranged on the third pipe line. In addition to the flow rate that has passed through the pressure reducing valve, the assist flow rate that has passed through the throttle of the third pipeline can be combined and flowed into the second pipeline, so the rise of the secondary pressure can be accelerated. The response of pressure adjustment of the pressure reducing valve can be improved. In addition, since the assist flow rate from the third conduit passes through the throttle, it can flow into the second conduit in a heat-generating state and have a warm-up function.

As described above, the responsiveness of the pressure reducing valve can be improved and the responsiveness of the switching operation of the directional control valve can be improved by improving the responsiveness of the pressure reducing valve and providing the warm-up function. (2) In the above (1), it is preferable that the throttle arranged in the third pipeline be provided near a connection point between the second pipeline and the third pipeline.

As a result, the volume of the second conduit is not increased more than necessary, so that the responsiveness of the pressure regulating valve can be improved and the responsiveness of the switching operation of the directional control valve can be improved. (3) Further, in the above (1), preferably, the check valve and the throttle arranged in the third conduit are provided near the pressure chamber in the pressure receiving portion of the directional control valve.

This makes it possible to protect the comfort of the living space of the operator's cab in which the operation lever device is arranged, by separating the diaphragm, which is the heat generating portion, from the operation lever device. (4) In the above (1), preferably, the operation lever device is an electric operation lever device, the pressure reducing valve is an electromagnetic proportional pressure reducing valve, and an input command from the electric operation lever device is provided. A controller that outputs a drive signal to the electromagnetic proportional pressure reducing valve according to the amount is provided.

With this configuration, the pilot pressure generating section is constituted by an electric system, and the response of pressure adjustment of the electromagnetic proportional pressure reducing valve is improved and the warm-up function is provided to improve the response of the switching operation of the directional control valve. can do. (5) Further, in the above (1), preferably, the operation lever device is a hydraulic operation lever device including the pressure reducing valve.

With this configuration, the pilot pressure generating section is constituted by the hydraulic mechanical system, and the response of the pressure reducing valve is improved and the warm-up function is provided to improve the response of the switching operation of the directional control valve. be able to. (6) Further, in the above (1), preferably, a plug is attached to a pilot cap constituting a pressure receiving portion of the directional control valve, the third pipe line is connected to the plug, and the check valve is connected. It is assumed that the diaphragm is arranged and formed in the plug.

As a result, the check valve and the throttle are built in the pilot cap, and the pilot operating device can be simplified and downsized. (7) Further, in the above (1), preferably, an internal oil passage forming a part of the third pipe passage is formed in a pilot cap forming a pressure receiving portion of the directional control valve, and the check valve is formed. And a diaphragm is arranged and formed in the pilot cap.

As a result, the check valve and the throttle are built in the pilot cap, and the pilot operating device can be simplified and downsized. Moreover, since a part of the third pipe line is formed as the internal oil passage of the pilot cap,
In the case of a valve device with a multiple structure in which a plurality of directional control valve spools are arranged in parallel in the same casing, the internal oil passage can be commonly used, and the valve with a multiple structure is excellent. The device can be simplified and downsized.

Further, in the pilot cap 150A, an oil passage (8) forming a part of the third pipe passage 12a, and in the above (1), preferably, in the main body casing of the directional control valve and the spool valve body. It is assumed that an internal oil passage that constitutes a part of the third pipe passage is formed, and the check valve and the throttle are arranged and formed in the spool valve body.

As a result, the check valve and the throttle are built in the spool valve body, and the pilot operating device is simplified.
It can be miniaturized. Further, since a part of the third pipe line is formed as the internal oil passage of the main body casing, in the case of a valve device having a multiple structure in which a plurality of directional control valve spools are arranged in parallel in the same casing, the internal oil passage The passage can be used in common, excellent multiplicity, and a valve device having a multiple structure can be simplified and downsized.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

First, a first embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIG. This embodiment is an embodiment of a hydraulic circuit, and is a case where the pilot pressure generating portion of the pilot operating device is configured by an electric system.

In FIG. 1, reference numeral 50 denotes, for example, a three-position, four-port type directional switching valve. At both ends of the directional switching valve 50, pressure receiving portions 52a and 52b and a spring 53 for holding a neutral position are provided.
a and 53b are provided. In addition, the direction switching valve 50
The pump port of is connected to the main hydraulic pump 54,
The actuator port is connected to an actuator 55 such as a hydraulic cylinder, and the tank port is connected to a tank 56. By switching the direction switching valve 50, the flow direction and flow rate of the pressure oil supplied from the hydraulic pump 54 to the actuator 55 are controlled.
The direction and speed of motion of the are controlled.

The pilot operating device according to the present embodiment is for switching operation of such a directional control valve 50, and an electric operating lever device 1 for instructing the drive of the directional control valve 50 and this operation. A controller 2 that inputs a command signal (electrical signal) from the lever device 1 and outputs a drive signal (electrical signal) corresponding to the instruction signal, and an electromagnetic proportional pressure reducing valve 3a that operates by the drive signal from the controller 2, 3b and.

The primary ports of the electromagnetic proportional pressure reducing valves 3a, 3b are connected to the discharge passage 6 of the pilot hydraulic pump 5 via the first conduits 4a, 4b, and the secondary ports of the electromagnetic proportional pressure reducing valves 3a, 3b are It is connected to the pressure receiving portions 52a and 52b of the direction switching valve 50 via the second pipelines 7a and 7b, and the tank ports of the electromagnetic proportional pressure reducing valves 3a and 3b are tank lines 8a and 8b.
It is connected to the tank 56 via b and 8c.

The hydraulic pump 5 is driven to rotate by an engine (not shown) and discharges pressure oil to the discharge passage 6. A relief valve 9 is connected to the discharge passage 6, and the relief valve 9 regulates the discharge pressure of the hydraulic pump 5 to a constant pressure. First pipeline 4
The discharge pressure of the hydraulic pump 5 is guided to a and 4b as a primary pressure, and the electromagnetic proportional pressure reducing valves 3a and 3b reduce the primary pressure according to a drive signal from the controller 2 to generate a secondary pressure. This secondary pressure is output to the second pipelines 7a and 7b. The secondary pressure output to the second pipelines 7a and 7b is the directional control valve 50.
Guided by the pressure receiving portions 52a and 52b of the directional control valve 50, the directional control valve 50 is switched.

A construction machine such as a hydraulic excavator is provided with a plurality of actuators such as a boom cylinder and an arm cylinder, and the actuator 55 is, for example, one of those actuators. Further, in the hydraulic drive system for the construction machine, a directional control valve similar to the directional control valve 50 shown in the figure is provided for other actuators, and a pilot operating device similar to the pilot operating device shown in the figure is provided. In this case, the discharge passage 6 of the hydraulic pump 5 can be connected to a similar electromagnetic proportional pressure reducing valve of those pilot operating devices.

FIG. 2 shows the structure of a conventional general pilot operating device as a comparative example. In the figure, the same components as those of the pilot operating device according to the present embodiment shown in FIG. 1 are designated by the same reference numerals.

As can be seen from the comparison between FIG. 1 and FIG. 2, the configuration of the pilot operating device according to the present embodiment described so far is the same as that of the conventional general pilot operating device, and the pilot according to the present embodiment is the same. The operating device is different from the conventional pilot operating device in that the operating device further includes the following configuration.

That is, returning to FIG. 1, the pilot operating device according to the present embodiment has the third conduits 12a, 1 which connect the discharge conduit 6 of the hydraulic pump 5 and the second conduits 7a, 7b, respectively.
2b and the third conduits 12a, 12b, and allows the flow of pressure oil from the discharge conduit 6 into the second conduits 7a, 7b, and the pressure from the second conduits 7a, 7b into the discharge conduit 6. Check valves (check valves) 13a and 13b for blocking the flow of oil, and the third pipeline 1
There are throttles 14a, 14b arranged on the third conduits 12a, 12b between the check valves 13a, 13b and the connection points between the 2a, 12b and the second conduits 7a, 7b. In this case, the third conduits 12 a and 12 b are connected to the first conduit via the discharge conduit 6.
It will also be connected to the pipelines 4a, 4b.

Next, the operation of the pilot operating device of the present embodiment will be described in comparison with that of the prior art shown in FIG.

In FIG. 1, when the operation lever 1a of the electric operation lever device 1 is operated with the intention of switching the direction switching valve 50 to the right in the figure, a command signal from the operation lever device 1 is sent to the controller 2. In response to the input command, the controller 2 selects the electromagnetic proportional pressure reducing valve 3a or 3b corresponding to the switching operation of the directional switching valve 50. In this operation example, the electromagnetic proportional pressure reducing valve 3a is selected and its drive signal is selected. Is performed, and a drive signal is output to the proportional solenoid of the corresponding electromagnetic proportional pressure reducing valve 3a. These series of operations are general, and are the same in the conventional technique shown in FIG. Further, no special program control such as correction of the control calculation as in the above-mentioned JP-A-5-195546, JP-A-8-210305 and JP-A-2000-205204 is required. As a result, the electromagnetic proportional pressure reducing valve 3a generates a pilot pressure (secondary pressure) for switching the direction switching valve 50 to the right in the drawing, and outputs the pilot pressure to the second conduit 7a. Second
The pilot pressure (secondary pressure) output to the conduit 7a is guided to the pressure receiving portion 52a of the directional control valve 50, and the oil pressure due to the pilot pressure (secondary pressure) and the spring 53b facing the oil pressure.
The spool valve element of the directional control valve 50 is displaced to the right in the figure in accordance with the balance with the urging force of.

Details of the operating conditions of the respective parts in the above operation will be described with reference to FIGS. 3 and 4. FIG. 3 is a characteristic diagram showing the operating condition of the conventional technique shown in FIG. 2, and FIG. 4 is a characteristic diagram showing the operating condition of the present embodiment shown in FIG. In these characteristic diagrams, the spool displacement of the direction switching valve 50 and the spool displacement of the electromagnetic proportional pressure reducing valve 3a when the operation lever 1a of the operation lever device 1 is operated are Sy and S, respectively.
x, the secondary pressure of the electromagnetic proportional pressure reducing valve 3a is P2, the inflow flow rate from the electromagnetic proportional pressure reducing valve 3a to the second pipeline 7a is Q1, and the changes thereof are shown in time series. Further, in FIG. 4, the inflow flow rate (assist flow rate) from the third pipeline 12a to the second pipeline 7a is Q3, and its change is also shown.

First, in the case of the conventional pilot operating device shown in FIG. 2, when the operating lever 1a of the operating lever device 1 is operated (time t1), a drive signal is output from the controller 2 to the electromagnetic proportional pressure reducing valve 3a, and the electromagnetic proportional valve is output. The control spool of the pressure reducing valve 3a is maximally displaced so that the connection opening between the primary port and the secondary port is fully opened. As a result, pressure oil flows from the secondary port of the electromagnetic proportional pressure reducing valve 3a into the second pipe line 7a, the secondary pressure P2 starts to rise, and the force of the spring 53b against which the spool valve body of the directional control valve 50 opposes. It begins to displace according to the balance of.

Thereafter, as the secondary pressure P2 rises, the pressure difference from the primary pressure disappears, so the connection opening between the primary port and the secondary port of the electromagnetic proportional pressure reducing valve 3a is fully opened (the pressure reducing valve displacement Sx is the maximum. ), The inflow flow rate Q1 into the second pipeline 7a is limited so as to gradually decrease, and the secondary pressure P2
Rises slowly. Further, the volume of the pressure chamber of the pressure receiving portion 52a increases with the movement of the spool valve element of the direction switching valve 50,
This also makes the rise of the secondary pressure P2 slow. That is,
The rising of the secondary pressure P2 is delayed. And the secondary pressure P2
When the control spool of the electromagnetic proportional pressure reducing valve 3a reaches a target value near the target value instructed by the drive signal of the controller 2, the control spool of the electromagnetic proportional pressure reducing valve 3a is in a steady position (connection opening between the primary port and the secondary pressure port and connection between the secondary port and the tank port). The opening is pushed back to a position where both openings are near zero), and at this steady position, the electromagnetic proportional pressure reducing valve 3a controls the pressure so that the target value of the secondary pressure P2 is maintained (time t2).

As described above, in the case of the conventional pilot operating device, the secondary pressure P is caused by the shortage of the flow rate into the second conduit 7a.
2 is delayed, and therefore the response of the switching of the directional control valve 50 is delayed (the switching time t2-t1 is long).

On the other hand, in the case of the present embodiment shown in FIG. 4, first, when the operation lever 1a of the operation lever device 1 is not operated, the third pipe lines 12a, 12b to the check valves 13a, 13b and the throttles are first operated. The assist flow rate Q3 is flowing into the second pipelines 7a and 7b via 14a. At this time, the connection openings of the secondary ports and tank ports of the electromagnetic proportional pressure reducing valves 3a, 3b are fully opened, and the assist flow rate Q3 flowing into the second pipelines 7a, 7b is the same as the electromagnetic proportional pressure reducing valves 3a, 3b. Pass through the tank lines 8a, 8b,
It is returned to the tank 56 via 8c. Here, the electromagnetic proportional pressure reducing valves 3a and 3b are set at the second position when the operation lever is in the neutral position.
The assist flow rate Q3 flowing into the pipelines 7a and 7b is the tank 5
The pressure drop until reaching 6 is small, and the second pipelines 7a, 7b
The pressure of the assist flow rate Q3 that has flowed into the valve becomes equal to or lower than the pressure corresponding to the initial setting force of the springs 53a and 53b of the directional control valve 50, and the spool valve body of the directional control valve 50 is not switched by the assist flow rate Q3. The opening area of the next port and the tank port is set.

When the operating lever 1a of the operating lever device 1 is operated (time t1), a drive signal is output from the controller 2 to the proportional solenoid of the electromagnetic proportional pressure reducing valve 3a, and the control spool of the electromagnetic proportional pressure reducing valve 3a becomes the primary port. It is displaced to the maximum so that the connection opening with the secondary port is fully opened. As a result, pressure oil flows into the second conduit 7a from the secondary port of the electromagnetic proportional pressure reducing valve 3a, and the secondary pressure P2 starts to rise due to the inflow flow rate Q1 and the assist flow rate Q3. In this way, the assist flow rate Q3 flows into the second pipeline 7a in addition to the inflow flow rate Q1, so that the secondary pressure P2 rises faster. Then, the spool valve element of the direction switching valve 50 starts to be displaced in accordance with the balance between the hydraulic pressure due to the secondary pressure P2 and the force of the spring 53b facing the hydraulic pressure.

Thereafter, as the secondary pressure P2 rises, the pressure difference from the primary pressure disappears, so the connection opening between the primary port and the secondary port of the electromagnetic proportional pressure reducing valve 3a is fully opened (the pressure reducing valve displacement Sx is maximum. ), The inflow flow rate Q1 into the second pipeline 7a is limited so as to gradually decrease, and the secondary pressure P2
Rises slowly. Further, the volume of the pressure chamber of the pressure receiving portion 52a increases with the movement of the spool valve element of the direction switching valve 50,
This also makes the rise of the secondary pressure P2 slow. Further, the differential pressure across the throttle 14a also decreases, and the assist flow rate Q3 also decreases. However, the secondary pressure P2 quickly reaches the vicinity of the target value instructed by the drive signal of the controller 2 due to the large inflow of the inflow flow rate Q1 and the assist flow rate Q3 immediately after the operation, and the electromagnetic proportional pressure reducing valve 3a is in the steady position. Then, pressure regulation control is performed so as to maintain the target value of the secondary pressure P2 (time t3).

As described above, in the pilot operating device according to the present embodiment, the assist flow rate Q3 is added through the third pipe line 12a provided with the check valve 13a and the throttle 14a, so that the operating lever device 1 is immediately after the lever input. Since a large amount of pressure oil can be made to flow into the second pipe line 7a, and therefore the required volume of flow amount can be secured with the movement of the spool valve element of the directional control valve 50 earlier, the rise of the secondary pressure P2 can be achieved. The responsiveness of the pressure adjustment of the electromagnetic proportional pressure reducing valve 3a is improved, and as a result, the responsiveness of the switching operation of the directional switching valve 50 can be improved (the switching time t3-t1 can be shortened).

Moreover, as shown in FIG.
Since the diaphragms 14a and 14b arranged at a and 12b are provided in the vicinity of the connection points between the second pipelines 7a and 7b and the third pipelines 12a and 12b, the volume of the second pipelines 7a and 7b becomes unnecessary. Without increasing the pressure, the secondary pressure P2 can be quickly raised by the inflow of the assist flow rate into the second pipelines 7a and 7b as described above.

The assist flow rate Q3 is determined by the third conduit 12
Since it passes through the throttles 14a and 14b on the a and 12b, it flows into and circulates in the second pipelines 7a and 7b in a heat-generating state, and this warming-up effect reduces the viscous resistance of the working fluid. Also, the responsiveness of switching of the directional control valve 50 can be improved.

As described above, according to the present embodiment, the response of the pressure adjustment of the electromagnetic proportional pressure reducing valves 3a and 3b is improved and the warm-up function is provided without depending on the software processing.
The responsiveness of the switching operation of the direction switching valve 50 can be improved.

The check valves 13a and 13b and the throttles 14a and 14b arranged in the third pipelines 12a and 12b are
Since it is provided in the vicinity of the direction switching valve 50, the throttles 14a and 14b, which are heat generating parts, and the operation lever device 1 can be installed separately, and the comfort of the driver's cab in which the operation lever device 1 is installed is protected. be able to.

A second embodiment of the present invention will be described with reference to FIG. In the present embodiment, the pilot pressure generating portion of the pilot operating device is configured by a hydraulic mechanical system. 5, those parts that are the same as those corresponding parts in FIG. 1 are designated by the same reference numerals.

In FIG. 5, the pilot operating device of the present embodiment has a hydraulic operating lever device 31 generally called a hydraulic remote control valve, and this operating lever device 31 includes an operating lever 31a and pressure reducing valves 32a, 32b. It is composed of springs 33a and 33b for transmitting the operating force of the operating lever 31a to the pressure reducing valves 32a and 32b.

The primary ports of the pressure reducing valves 32a and 32b are connected to the discharge passage 6 of the pilot hydraulic pump 5 via the first pipelines 4c and 4d, and the secondary ports of the pressure reducing valves 32a and 32b are the second pipelines. The pressure receiving portions 52a and 52b of the direction switching valve 50 are connected via 7a and 7b, and the tank ports of the pressure reducing valves 32a and 32b are connected to the tank 56 via tank lines 8d and 8c.

The above-mentioned structure is the same as that of the conventional pilot operating device in which the conventional general pilot pressure generating part is constituted by the hydraulic mechanical system.

The pilot operating device according to the present embodiment connects the discharge passage 6 of the hydraulic pump 5 and the second pipelines 7a and 7b, respectively, as in the first embodiment shown in FIG. Third pipeline 12a, 12b and third pipeline 12
It is provided with check valves 13a, 13b and throttles 14a, 14b arranged on a, 12b. In this case, the third
The pipe lines 12a and 12b are connected to the first pipe line 4c via the discharge line 6,
It will also be connected to 4d.

Also in the present embodiment having such a configuration, the check valves 13a and 13b and the throttle 1 are also operated when the direction switching valve 50 is switched by the operating lever device 31.
The assist flow rate that flows into the second pipelines 7a and 7b via 4a and 14b can increase the inflow rate immediately after the lever is input, speeding up the rise of the pilot secondary pressure P2 and switching the directional control valve 50. To improve responsiveness,
The same effect as that of the first embodiment can be obtained with the pilot pressure generating unit configured by the hydraulic mechanical system.

FIG. 6 shows the third and fourth embodiments of the present invention.
And FIG. 7. These embodiments are different from the embodiments shown in FIGS. 1 and 5 in that the connecting position of the third conduit provided with the check valve and the throttle is changed to the second conduit. In the figure, the same parts as those shown in FIGS. 1 and 5 are designated by the same reference numerals.

In FIG. 6, the pilot operating device according to the present embodiment is similar to that of the first embodiment in that the pilot pressure generating portion is constituted by an electric system. , Controller 2 and electromagnetic proportional pressure reducing valves 3a, 3b. Electromagnetic proportional pressure reducing valve 3a,
3b is incorporated in the casing body 21, and the third conduits 12Aa, 12Ab provided with the check valves 13a, 13b and the throttles 14a, 14b are connected to the second conduits 7a, 7b in the casing body 21.

In FIG. 7, the pilot operating device according to this embodiment is similar to that of the second embodiment in that the pilot pressure generating portion is constituted by a hydraulic mechanical system, and pressure reducing valves 32a and 32b are provided. A hydraulic operation lever device 31 is provided. The pressure reducing valves 32a and 32b are incorporated in the casing body 22, and the check valves 13a and 32b
Third conduit 1 including 13b and throttles 14a, 14b
2Ba and 12Bb are the second inside the casing body 22.
It is connected to the pipelines 7a and 7b.

The same effects as those of the first and second embodiments can be obtained by the third and fourth embodiments.

Further, according to the third and fourth embodiments, the third conduits 12Aa, 12Ab or 12Ba, 12B.
b is an electromagnetic proportional pressure reducing valve 3a, 3b or pressure reducing valve 32a, 32
b inside the casing body 21 or 22 of the second conduit 7a, 7
Since it is connected to b, the discharge passage 6 of the pilot hydraulic pump 5
It is not necessary to route the pipe of the third pipe extending from the direction switching valve 50 side, and the overall configuration can be simplified.

The fifth to eighth embodiments of the present invention will be described with reference to FIGS.
This will be described with reference to FIG. These embodiments show embodiments of an apparatus for realizing the embodiments of the hydraulic circuit shown in FIGS. 1 and 5, and in FIGS.
The same parts as those shown in are denoted by the same reference numerals.

FIG. 8 shows a fifth embodiment of the present invention. In FIG. 8, 100 is a main casing of the directional control valve 50. A spool valve body 102 is inserted into a spool hole 101 in the body casing 100, and the end portion of the spool valve body 102 is located in the body casing 100.
A pilot cap 150 that constitutes the pressure receiving portion 52 a is attached to the end surface of the pilot cap 150, and a pressure chamber 151 is formed inside the pilot cap 150. Inside the pressure chamber 151, a stopper 110 that comes into contact with the end of the spool valve body 102 and is movable, and a spring 53a are mounted. Also,
An oil passage 152 that communicates with the pressure chamber 151 and a port 156 that communicates the oil passage 152 with the second conduit 7 a are formed in the pilot cap 150.

The adapter 200 is attached to the end of the pilot cap 150, and the third conduit 1 is attached to the adapter 200.
An oil passage 202 connected to 2a and a cylinder hole 201 having a larger diameter than the oil passage 202 and a seat portion 203 formed between the oil passage 202 are formed, and the cylinder hole 201 functions as a check valve 13a. The check valve body 125 is fitted so as to be able to slide closely. A small hole 126 that functions as the throttle 14a is formed in the check valve body 125, and the valve chamber 130 on the outer peripheral side of the check valve body 125 communicates with the back pressure chamber 204 of the check valve body 125 via the small hole 126. . In addition, the back pressure chamber 20 of the check valve body 125 of the adapter 200
A stopper 205 having an oil passage 206 is fixed to the fourth side, and the back pressure chamber 204 communicates with the oil passage 152 via the oil passage 206.

The above is the electromagnetic proportional pressure reducing valve 3 of the direction switching valve 50.
The side corresponding to "a" and the side corresponding to the electromagnetic proportional pressure reducing valve 3b (the end side opposite to the spool valve body 102) are also configured similarly.

According to this embodiment, the same effect as that of the first embodiment can be obtained, and the check valve having the small hole 126 (throttle 14a) built in the adapter 200 to which the third conduit 12a is connected. Since the body 125 (check valve 13a) is arranged, the pilot operating device is simplified,
It can be miniaturized.

FIG. 9 shows a sixth embodiment of the present invention, in which a check valve and a throttle are arranged in the pilot cap. In the figure, the same members as those shown in FIG. 8 are designated by the same reference numerals.

In FIG. 9, a pilot cap 150A is attached to the end surface portion of the main body casing 100 where the end portion of the spool valve body 102 is located, and a pressure chamber 151 is formed inside the pilot cap 150A. A cylinder hole 153 communicating with the pressure chamber 151 via the oil passage 152 is formed in the pilot cap 150A, and the check valve body 125A functioning as the check valve 13a is fitted in the cylinder hole 153 so as to be capable of sliding closely. Has been inserted. An adapter 200A is attached to an end of the pilot cap 150A, an oil passage 202A connected to the second pipe passage 7a is formed in the adapter 200A, and the oil passage 202A is formed in the back pressure chamber 128 of the check valve body 125A. Oil passage 127 and oil passage 15 formed in the check valve body 125A
It communicates with the pressure chamber 151 via 2.

The cylinder hole 153 has a larger diameter than the oil passage 152, and a seat portion 155 is formed between the cylinder hole 153 and the oil passage 152.
A valve chamber 131 is formed adjacent to the seat portion 155 on the outer peripheral side of the check valve body 125, and the valve chamber 131 is formed by the third conduit 12a.
Is connected to an oil passage 154 that constitutes a part of. Also,
When the check valve body 125A is disengaged from the seat portion 155, the back pressure chamber 128 side moves to the end portion of the adapter 200A, so that the throttle portion 126A that functions as the throttle 14a is formed between the check valve body 125A and the seat portion 155.

The above is the electromagnetic proportional pressure reducing valve 3 of the direction switching valve 50.
The side corresponding to "a" and the side corresponding to the electromagnetic proportional pressure reducing valve 3b (the end side opposite to the spool valve body 102) are also configured similarly.

According to this embodiment, the same effect as that of the first embodiment can be obtained, and the check valve body 125A (check valve 13) is provided in the pilot cap 150A.
Since a) and the throttle portion 126A (diaphragm 14a) are arranged and formed, the pilot operating device can be simplified and downsized as in the fifth embodiment.

Further, since the oil passage 154 forming a part of the third pipe passage 12a is formed in the pilot cap 150A, a valve device having a multiple structure in which a plurality of directional control valve spools are arranged in parallel in the same casing. If the oil passage 15
4 (third conduit 12a) can be used as a common internal oil passage, which has excellent multiplicity and can simplify and miniaturize a valve device having a multi-structure.

FIG. 10 shows a seventh embodiment of the present invention, in which the seat portion and the throttle of the check valve are provided on the plug side as compared with the sixth embodiment shown in FIG. is there. In the figure, the same members as those shown in FIGS. 8 and 9 are designated by the same reference numerals.

In FIG. 10, the seat portion 208 is formed at the end of the plug 200B, and the back pressure chamber 128 of the check valve body 125B is formed at the oil passage 152 side.
When 25B is detached from the seat portion 208, the back pressure chamber 12
The squeeze portion 12 that functions as the squeeze 14a with the seat portion 208 by moving the 8 side to the step portion with the oil passage 152
6B is formed.

The above is the electromagnetic proportional pressure reducing valve 3 of the direction switching valve 50.
The side corresponding to "a" and the side corresponding to the electromagnetic proportional pressure reducing valve 3b (the end side opposite to the spool valve body 102) are also configured similarly.

Also according to the present embodiment, the same effect as that of the sixth embodiment can be obtained.

FIG. 11 shows an eighth embodiment of the present invention, in which a check valve and a throttle are arranged in a spool valve body. In the figure, the same members as those shown in FIGS. 8 to 10 are designated by the same reference numerals.

In FIG. 11, the pilot cap 15
The second conduit 7a of the adapter 200A provided at the 0A end
The oil passage 202A connected to is directly connected to the pressure chamber 151 via the oil passage 152.

An oil passage 107 forming a part of the third conduit 12a is formed in the directional control valve body casing 100, and a port 106 is formed around the spool hole 101 to open the oil passage 107. There is.

A port 106 is provided in the spool valve body 102.
A radial oil passage 104 and an axial oil passage 105 communicating with
And a cylinder hole 109 having a larger diameter than the oil passage 105 and having a seat portion 108 formed between the oil passage 105 and the cylinder hole 109. A check valve body 125C functioning as the check valve 13a slides in the cylinder hole 109 closely. It is possible to be inserted.
A small hole 126C that functions as the throttle 14a is formed in the check valve body 125C, and the valve chamber 132 on the outer peripheral side of the check valve body 125C is checked through the small hole 126C.
It communicates with the back pressure chamber 204 of 5C. A stopper 205C having an oil passage 206 is fixed to the check valve body 125C of the spool valve body 102 on the back pressure chamber 204 side, and the back pressure chamber 204 communicates with the pressure chamber 151 via the oil passage 206. .

The above is the electromagnetic proportional pressure reducing valve 3 of the direction switching valve 50.
The side corresponding to "a" and the side corresponding to the electromagnetic proportional pressure reducing valve 3b (the end side opposite to the spool valve body 102) are also configured similarly.

According to this embodiment, the same effect as that of the first embodiment can be obtained, and the spool valve element 102 can be obtained.
Since the check valve body 125C (check valve 13a) and the throttle portion 126C (throttle 14a) are arranged and formed therein, the pilot operating device can be simplified and downsized as in the fifth and sixth embodiments. it can.

Further, since the oil passage 107 forming a part of the third pipe passage 12a is formed in the directional control valve casing main body 100, a multiple structure in which a plurality of directional control valve spools are arranged in parallel in the same casing. In the case of the above valve device, the oil passage 107 (third pipe passage 12a) can be used as a common internal oil passage, and as in the sixth embodiment, it has excellent multi-linkage and multi-link structure. The valve device can be simplified and downsized.

[0086]

According to the present invention, the responsiveness of the pressure regulating valve is improved and the warming function is provided without depending on the software processing, so that the responsiveness of the switching operation of the directional control valve is improved. be able to.

[Brief description of drawings]

FIG. 1 is a diagram showing a hydraulic circuit of a pilot operating device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a conventional operating pilot operating device in a hydraulic circuit.

FIG. 3 is a characteristic diagram showing an operating condition of a pilot operating device having a conventional configuration.

FIG. 4 is a characteristic diagram showing an operating condition of the pilot operating device according to the present invention.

FIG. 5 is a diagram showing a hydraulic circuit of a pilot operating device according to a second embodiment of the present invention.

FIG. 6 is a diagram showing a hydraulic circuit of a pilot operating device according to a third embodiment of the present invention.

FIG. 7 is a diagram showing a pilot operating device in a hydraulic circuit according to a fourth embodiment of the present invention.

FIG. 8 is a view showing a pilot operating device according to a fifth embodiment of the present invention in a sectional view of a pressure receiving portion of a directional control valve and in a hydraulic circuit of other portions.

FIG. 9 is a sectional view showing a pressure receiving portion of a directional control valve of a pilot operating device according to a sixth embodiment of the present invention.

FIG. 10 is a sectional view showing a pressure receiving portion of a directional control valve of a pilot operating device according to a seventh embodiment of the present invention.

FIG. 11 is a sectional view showing a pressure receiving portion of a directional control valve of a pilot operating device according to an eighth embodiment of the invention.

[Explanation of symbols]

1 Electric operation lever device 2 controller 3a, 3b Electromagnetic proportional pressure reducing valve 4a, 4b 1st pipeline 5 Pilot hydraulic pump 6 discharge paths 7a, 7b 2nd pipeline 8a, 8b, 8c, 8d Tank line 9 relief valve 12a, 12b Third pipeline 13a, 13b check valve 14a, 14b diaphragm 31 Hydraulic operation lever device 31a Operation lever 32a, 32b Pressure reducing valve 33a, 33b spring 21 Casing body 22 Casing body 50 directional valve 52a, 52b Pressure receiving part 53a, 53b springs 54 Main hydraulic pump 55 Actuator 100 body casing 101 spool hole 102 spool valve body 105 oilway 106 port 107 oil passage 108 seat 110 stopper 125 check valve body (check valve) 126 small holes (iris) 126B diaphragm 127 oil passage 128 back pressure chamber 130 valve chambers 131 valve chamber 132 valve chamber 150 pilot cap 151 Pressure chamber 152 Oil passage 153 Cylinder hole 154 oil passage 155 seat section 156 ports 200 adapter 201 cylinder hole 202 oil passage 203 seat 204 Back pressure chamber 205 stopper 206 oil passage 208 seat Sy Directional switching valve displacement Sx Pressure reducing valve displacement P2 secondary pressure Q1 Pressure reducing valve inflow Q3 Assist flow rate

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2D003 AA01 AC06 BA01 CA02 DA03                       DA04                 3H082 AA07 AA22 BB17 CC02 DB06                       DE05 EE02                 3H089 AA60 BB14 BB22 CC01 DA02                       DA13 DB46 DB49 EE05 EE07                       EE13 EE22 EE36 HH05 JJ02

Claims (8)

[Claims] Claim: What is claimed is: 1. A first conduit in which a discharge pressure of a hydraulic pump defined by a relief valve is guided as a primary pressure, and the primary pressure is reduced according to an input command amount from an operating lever device to generate a secondary pressure. Pressure reducing valve and a second pipe line through which the secondary pressure of the pressure reducing valve is output. In a pilot operating device for a directional control valve that switches and operates a directional control valve by a secondary pressure of the valve, a third pipeline connecting the first pipeline and the second pipeline is provided, and on the third pipeline. A directional control valve having a throttle and a check valve for permitting the inflow from the first pipeline to the second pipeline and blocking the flow from the second pipeline to the first pipeline. Pilot operating device. 2. A pilot operating device for a directional control valve according to claim 1, wherein a throttle arranged in said third pipe line is provided near a connection point between said second pipe line and said third pipe line. A pilot operated device for a directional control valve. 3. The pilot operating device for a directional control valve according to claim 1, wherein the check valve and the throttle arranged in the third pipe line are provided near a pressure chamber in a pressure receiving portion of the directional control valve. A pilot operated device for a directional control valve. 4. The pilot operating device for a directional control valve according to claim 1, wherein the operating lever device is an electric operating lever device, and the pressure reducing valve is an electromagnetic proportional pressure reducing valve,
A pilot operation device for a directional control valve, comprising a controller that outputs a drive signal to the electromagnetic proportional pressure reducing valve according to an input command amount from the electric operation lever device. 5. The pilot operating device for a directional control valve according to claim 1, wherein the operating lever device is a hydraulic operating lever device including the pressure reducing valve. 6. A pilot operating device for a directional control valve according to claim 1, wherein a plug is attached to a pilot cap forming a pressure receiving portion of the directional control valve, and the third pipe line is connected to the plug. A pilot operating device for a directional control valve, wherein the check valve and the throttle are arranged and formed in the plug. 7. A pilot operating device for a directional control valve according to claim 1, wherein an internal oil passage forming a part of said third pipeline is formed in a pilot cap constituting a pressure receiving portion of said directional control valve. A pilot operating device for a directional control valve, wherein the check valve and the throttle are arranged and formed in the pilot cap. 8. A pilot operating device for a directional control valve according to claim 1, wherein an internal oil passage forming a part of said third pipeline is formed in the main body casing of said directional control valve and in said spool valve body. A pilot operating device for a directional control valve, wherein the check valve and the throttle are arranged and formed in the spool valve body.