JP4144310B2 - Pilot switching valve, pilot circuit and mobile crusher - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pilot switching valve that opens and closes a pilot passage by operating an electromagnetic valve to stroke a main spool, a pilot circuit provided with the switching valve, and a mobile crusher incorporating the circuit.
[0002]
[Prior art]
The conventional technology will be described by taking a mobile crusher configured by using a hydraulic excavator base machine as an example.
[0003]
A mobile crusher consists of a crusher and auxiliary equipment such as a feeder and a belt conveyor installed on the upper body mounted on the crawler-type traveling body. The power line is used to approach the object to be processed, and crushing is performed.
[0004]
FIG. 3 shows a part of the hydraulic circuit of this mobile crusher.
[0005]
1 is a first hydraulic pump, 2 is a second hydraulic pump, the first hydraulic pump 1 is used as a hydraulic power source for left travel and crusher, and the second hydraulic pump 2 is used for right travel and is used for feeders, belt conveyors, etc. Used as a hydraulic power source for auxiliary equipment.
[0006]
Both pumps 1, 2 are connected to respective actuators (hydraulic motors or hydraulic cylinders) via switching valves (control valves) 3, 4, 5, 6 for left running, crusher, right running, and auxiliary equipment. Of these, the left and right traveling switching valves 3 and 5 are remotely operated by the traveling remote control valve 7.
[0007]
For safety, the mobile crusher needs to be locked so that it cannot travel during the crushing operation, and conversely, it must be locked so that the crusher and other crushing devices are not driven during traveling.
[0008]
Therefore, the pilot pump 11 is connected via a start valve 9 that opens the primary pilot line 8 of the travel remote control valve 7 when the engine is started, and a travel stop valve 10 that shuts off the pilot line 8 during crushing operation and disables travel. And by supplying the primary pilot pressure to the traveling remote control valve 7 with both valves 9 and 10 open, the operation of the remote control valve 7 becomes effective and the crusher can travel. It is configured.
[0009]
Among the switching valves 3 to 6, the traveling switching valves 3 and 5 are configured as hydraulic pilot valves, while the crusher and auxiliary switching valves 4 and 6 are electromagnetic valves in which an electromagnetic valve is incorporated in the pilot drive unit. -It is configured as a hydraulic pilot valve, and when the solenoid valve is energized, the pilot passage is opened, the pilot pressure is supplied to the pilot chamber, and the main spool is operated in a stroke.
[0010]
The main supply / exhaust path to the actuator side of each device is not shown.
[0011]
Here, the switching valves 3, 4 and 5 for left running, crusher, and right running are configured as a double-sided drive type pilot valve having pilot drive units 12 and 13 on both sides as shown in the figure. .
[0012]
On the other hand, since the auxiliary switching valve 6 only needs to perform an on-off valve action, the auxiliary switching valve 6 is configured as a one-side drive type pilot valve in which the pilot drive unit 12 is provided only on one side.
[0013]
In this case, a double-sided drive valve is generally used as a pilot valve, and it can be obtained as a general-purpose product at a low cost. A one-side driven pilot valve is configured with the passage and the like intact.
[0014]
FIG. 4 shows a specific structure of the auxiliary switching valve 6 adopting this one-side drive system.
[0015]
A main spool 15 is provided in a valve block (valve case) 14 to perform a switching valve action by operating a stroke, and a pilot chamber for applying a pilot pressure as a stroke drive source to the main spool 15 on both sides of the main spool 15. 16 and 17, pilot passages 18 and 19 for introducing pilot pressure PP into the pilot chambers 16 and 17 on both sides, and return springs 20 and 21 for returning the main spool 15 to the neutral direction are provided.
[0016]
In the case of a double-side driven pilot valve, a solenoid valve comprising a solenoid and a spool is provided in each side pilot passage, and when this solenoid valve is operated, the pilot passage is opened and pilot pressure PP is introduced into the pilot chamber 16 from the outside.
[0017]
On the other hand, in the case of this auxiliary switching valve 6 that adopts the one-side drive system, the solenoid valve 22 is provided only in one of the two-side pilot passages 18 and 19 (left pilot passage 18 in the example shown in the figure, which will be described below). Is provided to constitute the pilot drive unit 12, and the main spool 15 is stroked from the left side to the right side by the operation of the electromagnetic valve 22 of the pilot drive unit 12.
[0018]
At this time, since it is necessary to drain the pilot oil in the right pilot chamber 17 to the tank, the plug hole 23 of the pilot chamber 17 is connected to the tank as a tank port.
[0019]
As described above, the pilot chamber 17 is connected to the tank through the plug hole 23 so that the spool 15 is not operated even if pilot pressure is supplied from the pilot line 19.
[0020]
[Problems to be solved by the invention]
However, in this way, the right solenoid valve originally provided in the auxiliary switching valve 6 is removed and closed with the plug 24, and the functions of the right pilot chamber 17 and the pilot passage 19 (= the function of the pilot drive unit) are achieved. On the other hand, according to the conventional circuit configuration in which two independent solenoid valves, the start valve 9 and the travel stop valve 10 shown in FIG. 4, are provided, the number of valves increases and the valve block becomes large. The system configuration is complicated, the cost is high, and the space utilization efficiency is poor.
[0021]
In particular, in the case of a small mobile crusher, the space problem has been desired to be improved because there is a demand for omitting even one valve because there is not enough room.
[0022]
Therefore, the present invention effectively uses one unused pilot drive unit as an independent valve, saves space in the hydraulic circuit, simplifies the configuration, and thereby achieves cost reduction. And a mobile crusher.
[0023]
[Means for Solving the Problems]
According to the first aspect of the present invention, a pilot chamber that applies a pilot pressure as a stroke driving source to the main spool is provided on both sides of the main spool that performs a valve action by operating a stroke, and a pilot passage that introduces the pilot pressure into the pilot chamber on both sides And a solenoid driving valve that opens and closes the pilot passages on both sides, and a main spool stroke in a direction in which the pilot oil in the pilot chamber is compressed in the pilot chamber of one pilot driving unit. A stopper for preventing the operation is provided, and a pilot chamber of the other pilot drive unit is provided with a spring for neutral return and an output port for taking out the pilot pressure in the pilot chamber to the outside.
[0024]
According to a second aspect of the present invention (pilot circuit), an external pilot line for extracting the pilot pressure in the pilot chamber is connected to the output port of the other pilot drive section in the pilot switching valve according to the first aspect.
[0025]
The invention of claim 3 (mobile crusher) is a mobile crusher in which an upper body is mounted on a lower traveling body, and a crusher and its peripheral equipment are installed on the upper body. The pilot switching valve is provided in the hydraulic circuit, and the primary pilot line of the remote control valve for operating the hydraulic actuator is connected to the output port of the pilot switching valve.
[0026]
According to the above configuration, the stroke operation of the main spool is limited to one direction by providing a stopper in place of the neutral return spring in one of the pilot chambers on both sides, and the one side drive system is substantially achieved. Since the pilot chamber is provided with an output port for taking out the pilot pressure of the pilot chamber to the outside, the pilot drive portion including the other pilot chamber, the pilot passage, and the electromagnetic valve can be operated as an independent valve of the electromagnetic valve system. .
[0027]
Therefore, as shown in claim 2, by connecting the output port of the pilot drive unit to an external pilot line (for example, the primary pilot line of the traveling remote control valve 7 in FIG. 3), the drive unit has an independent function. It can be used as (travel stop valve 10).
[0028]
As a result, the number of valves in the hydraulic circuit can be reduced and the valve block can be made smaller, so that space saving and cost reduction can be realized. In particular, it was applied to a small mobile crusher in terms of space saving. This is advantageous in the case (Claim 3).
[0029]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to FIGS.
[0030]
In the embodiment, the switching valve for auxiliary equipment in the mobile crusher exemplified in the description of the prior art is taken as an example of application.
[0031]
In FIG. 1, the same parts as those in FIG.
[0032]
The auxiliary switching valve 31 is configured as a double-side drive type electro-hydraulic pilot valve having pilot drive portions 32 and 33 on both sides as shown in the figure. The pilot drive unit 33 (described below in this example) functions as an independent electromagnetic valve, and only the left pilot drive unit 32 functions as the original switching drive unit.
[0033]
A specific structure will be described with reference to FIG.
[0034]
In the valve block (valve case) 34, a main spool 35 that operates as a stroke and operates as a switching valve as in the prior art, and a pilot chamber that applies a pilot pressure as a stroke drive source to the main spool 35 on both sides of the main spool 35. 36, 37, pilot passages 38, 39 for introducing the pilot pressure PP from the outside into the pilot chambers 36, 37 on both sides, and electromagnetic valves 40, 41 for opening and closing the pilot passages 38, 39 are provided.
[0035]
Here, in the conventional switching valve 6 shown in FIG. 4, the return springs 20 and 21 are provided in the pilot pilot chambers 16 and 17 on both sides, whereas in the switching valve 31, the return spring is provided in the right pilot chamber 37. On the other hand, a cylindrical stopper 43 is provided in the left pilot chamber 36 instead of the return spring, and the main oil in the direction (left direction) in which the pilot oil in the pilot chamber 36 is compressed by the stopper 43 is provided. The stroke operation of the spool 35 is prevented.
[0036]
That is, the switching valve 31 is configured as a one-side drive type valve in which the main spool 35 is stroked only in the right direction by the left pilot drive unit 32.
[0037]
Further, in this switching valve 31, an output port (a plug hole similar to the plug hole 23 used as a tank port in the conventional switching valve 6 shown in FIG. 4) is provided in the right pilot chamber 37 constituting the right pilot driving unit 33. 44), and a primary pilot line 45 (corresponding to the pilot line 8 in FIG. 3) of the traveling remote control valve 7 in the hydraulic circuit in FIG. 1 is connected to the output port 44.
[0038]
In this configuration, when the solenoid valve 40 of the left pilot drive unit 32 is operated, the pilot passage 38 is opened and the pilot pressure PP is applied to the pilot chamber 36, and the main spool 35 is stroked to the right side by the pilot pressure PP. The switching valve action is performed.
[0039]
On the other hand, when the solenoid valve 41 of the right pilot drive unit 33 is operated, the pilot passage 39 is opened and the pilot pressure is applied to the pilot chamber 37.
[0040]
At this time, since the main spool 35 is prevented from moving to the left by the stopper 43 and maintains the neutral position, the pilot pressure supplied to the right pilot chamber 37 is supplied to the travel remote control valve 7 via the output port 44 and the output line 45. Is supplied as a primary pilot pressure.
[0041]
That is, the right pilot drive unit 33 is an independent valve that controls the supply / shutoff of the primary pilot pressure to the travel remote control valve 7 regardless of the original valve action of the switching valve 31 (in the travel stop valve 10 of FIG. 3). Equivalent).
[0042]
Accordingly, since the travel stop valve 10 that is necessary in the hydraulic circuit of FIG. 3 is not required, the number of valves of the entire circuit is reduced, and the occupied space of the circuit can be reduced correspondingly.
[0043]
In addition, since the solenoid valves individually provided in the pilot line are configured using the solenoid valve port on the surplus side of the main switching valve in this way, the simultaneous operation of the traveling crusher and the crushing operation is prevented. The structure for the interlock as a safety device can be made simpler.
[0044]
Other Embodiments (1) In the above embodiment, the right pilot drive unit 33 is configured to act as an independent valve. Conversely, a stopper 43 is provided in the pilot chamber 37 of the right pilot drive unit 33. In addition, the left pilot drive unit 32 may be provided with a return spring 42 and an output port 44 so that the left pilot drive unit 32 acts as an independent valve.
[0045]
(2) Although the case where the start valve 9 which is one of the safety devices of the mobile crusher is provided is illustrated in the above embodiment, the start valve 9 is not limited to this form and may be omitted.
[0046]
(3) In the above embodiment, the switching valve for interlock provided in the hydraulic pilot line is taken as an example of the application as a safety device for preventing simultaneous operation of traveling and crushing work in the mobile crusher. Can be applied not only to a mobile crusher but also to a work machine equipped with two or more hydraulic drive devices that need to prevent simultaneous operation.
[0047]
For example, the present invention can be applied to an outrigger operation system and a traveling operation system of a wheel crane, a traveling system and a winch operation system in a crawler crane, and the like.
[0048]
The present invention is not limited to a circuit for preventing simultaneous operation, but can be applied to a hydraulic circuit of various work machines and its switching valve.
[0049]
【The invention's effect】
As described above, according to the present invention, among the pilot drive units on both sides of the switching valve, the pilot drive unit that is not used for driving the main spool can be used as an independent valve.
[0050]
As a result, the number of valves in the hydraulic circuit can be reduced and the valve block can be reduced in size, so that space saving and cost reduction can be realized. Especially in terms of space saving, a small mobile crusher (Claim 3) is advantageous.
[Brief description of the drawings]
FIG. 1 is a hydraulic circuit diagram of a mobile crusher in which a switching valve according to an embodiment of the present invention is used.
FIG. 2 is a partial cross-sectional front view showing a specific structure of the switching valve.
FIG. 3 is a hydraulic circuit diagram of a mobile crusher using a conventional switching valve.
FIG. 4 is a partial sectional front view showing a specific structure of the switching valve.
[Explanation of symbols]
31 Auxiliary switch valve 32, 33 as pilot switching valve Pilot drive part 34 of the switching valve Valve block 35 of the switching valve Same main spool 36, 37 Same pilot chamber 38, 39 Same pilot passage 40, 41 Same solenoid valve 42 Return spring 43 Stopper 44 Output port 7 Remote control valve 45 for moving crusher Primary pilot line (external pilot line) of the remote control valve

Claims (3)

A pilot chamber that applies a pilot pressure as a stroke drive source to the main spool, a pilot passage that introduces the pilot pressure into the pilot chamber on both sides, and a pilot passage on both sides A pilot drive unit having an electromagnetic valve for opening and closing is provided, and a stopper for preventing the stroke operation of the main spool in a direction in which the pilot oil in the pilot chamber is compressed is provided in the pilot chamber of one pilot drive unit And a pilot switching valve characterized in that a neutral return spring and an output port for extracting the pilot pressure in the pilot chamber to the outside are provided in the pilot chamber of the other pilot drive section. 2. A pilot circuit characterized in that an external pilot line for extracting pilot pressure in the pilot chamber is connected to the output port of the other pilot drive section in the pilot switching valve according to claim 1. An upper crusher is rotatably mounted on the lower traveling body, and the crusher and its peripheral equipment are installed on the upper body, wherein the pilot switching valve according to claim 1 is provided in the hydraulic circuit, A mobile crusher characterized in that a primary pilot line of a remote control valve for operating a hydraulic actuator is connected to an output port of the pilot switching valve.

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