JP4001833B2 - Anti-theft hydraulic equipment for construction machinery - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention mainly relates to a hydraulic apparatus that prevents theft of construction machines, industrial vehicles, and the like.
[0002]
[Prior art]
In recent years, theft of construction machinery has increased. Conventionally, for example, there is a hydraulic apparatus shown in FIG.
[0003]
This will be described. In a hydraulic apparatus for a construction machine that includes an operation lever 102 for switching and controlling various hydraulic actuator switching valves 101, a manually operated lock is provided in the middle of a pilot pressure passage 104 connecting the pilot pump 103 and the operation lever 102. An on-off valve 105 is interposed.
[0004]
In this case, if the keyed on-off valve 105 is operated to the blocking position of the passage 104, even if the engine key is unlocked and the engine 106 is driven to operate the pilot pump 103, various hydraulic actuator switching valves are used. The pilot pressure is not guided to 101, and the construction machine cannot be operated.
[0005]
[Patent Document 1]
Japanese Utility Model Publication No. 2-30755 [0006]
[Problems to be solved by the invention]
However, in such a conventional anti-theft hydraulic device for construction machinery, since the keyed on-off valve 105 is interposed in the middle of the pilot pressure passage 104, for example, the inlet side and the outlet of the keyed on-off valve 105 Each of the hydraulic pipes connected to the side is removed, so that there is a problem that the construction machine can be operated by introducing pilot pressure to the switching valve 101 for various hydraulic actuators.
[0007]
The present invention has been made in view of the above problems, and an object of the present invention is to provide an antitheft hydraulic device for a construction machine that cannot be easily restored by connection of hydraulic piping or the like.
[0008]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided an anti-theft hydraulic device for a construction machine, an unloading valve for returning hydraulic oil directed to an actuator to a tank side via a construction machine operation switching valve, and the unloading valve via a key. A locking device that opens and closes mechanically and a valve housing that houses a switching valve for operating a construction machine are housed in this valve housing together with an unloading valve and a locking device that switches the same, via a key when the construction machine is not in operation. By opening the unload valve, the hydraulic oil from the hydraulic pump is prevented from flowing to the construction machine operation switching valve.
[0009]
The second invention is the anti-theft hydraulic system for a construction machine, and unloading valve for recirculating hydraulic oil discharged from the oil pressure pump to the tank side, mechanically opening and closing the unloading valve via the key A locker and a pump housing for accommodating a hydraulic pump are provided, and an unload valve and a locker for switching the same are housed in the pump housing, and the unload valve is opened via a key when the construction machine is not in operation. Thus, the hydraulic oil from the hydraulic pump is not allowed to flow to the construction machine operation switching valve.
[0010]
According to a third aspect of the present invention, there is provided a relief valve for returning hydraulic oil discharged from the hydraulic pump to the tank side in response to an increase in the discharge pressure of the hydraulic pump in the anti-theft hydraulic device for construction machinery, and the relief valve. A valve housing that contains a shut-off valve that shuts off the flow of hydraulic oil discharged from the hydraulic pump downstream of the valve and a locker that mechanically opens and closes the shut-off valve via a key, and houses a switching valve for operating a construction machine The shut-off valve and a locker for switching the shut-off valve are housed together, and the shut-off valve is operated to be closed via a key when the construction machine is not in operation.
[0011]
A fourth invention is characterized in that, in the first or second invention, an unload valve that is switched via a locker is provided in the middle of the hydraulic piping.
A fifth invention is characterized in that, in the third invention, a shut-off valve that is switched via a locker is interposed in the middle of the hydraulic piping.
[0012]
Operation and effect of the invention
According to the first invention, since the unload valve is opened and closed via the locker, the construction machine cannot be moved unless the unload valve is switched to the closed position even if the locker is broken. For this reason, when the locker is broken, the actuator cannot be driven if the unload valve remains open.
[0013]
Further, when the locker and the unload valve are removed from the valve housing, the pressurized hydraulic fluid from the hydraulic pump leaks to the outside, the actuator cannot be driven, and a high antitheft effect is obtained. .
[0014]
According to the second invention, when the locker and the unload valve are removed from the pump housing, the pressurized hydraulic fluid from the hydraulic pump leaks to the outside, the actuator cannot be driven, and high theft Preventive effect is obtained.
[0015]
According to the third invention, since the shut-off valve is opened and closed via the locker, the construction machine cannot be moved unless the shut-off valve is switched to the open position even if the locker is broken.
[0016]
Further, when the locker and the shutoff valve are removed from the housing, the pressurized hydraulic fluid from the hydraulic pump leaks to the outside, the actuator cannot be driven, and a high antitheft effect is obtained.
[0017]
According to the fourth aspect of the invention, the antitheft effect can be further enhanced by additionally providing the hydraulic piping with the unload valve that can be switched via the locker.
According to the fifth aspect of the invention, the antitheft effect can be further enhanced by additionally providing the hydraulic piping with the shutoff valve that can be switched via the locker.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0019]
FIG. 1 is a hydraulic circuit diagram of a hydraulic operating device mounted on a construction machine such as a hydraulic excavator. This hydraulic operating device includes left and right traveling hydraulic motors 1 and 2 that drive left and right crawlers, and other hydraulic actuators (not shown) that drive work machines such as booms and buckets.
[0020]
A hydraulic pump 3 driven by the engine 4 is provided as a hydraulic source. The hydraulic pump 3 sucks the hydraulic oil in the tank 9 through the suction passage 8. The hydraulic oil discharged from the hydraulic pump 3 is supplied to the left and right traveling hydraulic motors 1 and 2 and each hydraulic actuator through the supply passage 5.
[0021]
The hydraulic oil discharged from the left and right traveling hydraulic motors 1 and 2 and each hydraulic actuator is returned to the suction passage 8 through the return passage 6. A relief valve 17 is interposed in a passage that short-circuits the supply passage 5 and the return passage 6.
[0022]
The hydraulic drive device includes a plurality of first and second passages 11 and 12 connected to the left and right traveling hydraulic motors 1 and 2 and the respective hydraulic actuators. The first and second passages 11 and 12 selectively communicate with the suction passage 8 and the return passage 6 via the construction machine operation switching valves 13. Each switching valve 13 switches the supply and discharge of the hydraulic oil to and from the hydraulic oil sent from a pilot pump (not shown) and adjusts the flow rate of the hydraulic oil.
[0023]
The variable displacement hydraulic pump 3 makes its discharge amount variable via a regulator valve 15 and an actuator 18. As for the regulator valve 15, the highest pressure among the load pressures led to the left and right traveling hydraulic motors 1, 2 and each hydraulic actuator as pilot pressure for operating the regulator valve 15 is led through each shuttle 16, and the pump discharge pressure is constant from the load pressure. Load sensing (load sensing) control is performed in which the discharge amount of the hydraulic pump 3 is adjusted via the actuator 18 so as to increase by the differential pressure.
[0024]
In order to prevent the theft of the construction machine, an unload valve 21 is provided in the passage from the hydraulic pump 3 to each switching valve 13 to return the hydraulic oil to the tank side. The unload valve 21 is connected via a key 40. A locker 30 that mechanically opens and closes is provided, and when the construction machine is not in operation, the unloading valve 21 is opened via the key 40, whereby the pressurized hydraulic fluid from the hydraulic pump 3 is circulated to each switching valve 13. The configuration is not allowed.
[0025]
In the present embodiment, as shown in FIG. 1, an unload passage 24 that short-circuits the supply passage 5 and the return passage 6 is provided, and an unload valve 21 is interposed in the middle of the unload passage 24.
[0026]
The unload valve 21 has an open position for opening the unload passage 22 and a closed position for closing the unload valve 21, and this open / close position is switched via the locker 30.
[0027]
The construction machine is mounted with a valve housing 31 shown in FIG. In the valve housing 31, each switching valve 13, the main relief valve 17 and the unload valve 21 are interposed, and a locker 30 is interposed. That is, the valve housing 31 houses both the unload valve 21 that stops the flow of the hydraulic oil guided to the traveling hydraulic motor 1 and the locker 30 that operates the unload valve 21.
[0028]
A locker mounting hole 32 is integrally formed in the valve housing 31, the unload valve 21 is stored in the inner part of the locker mounting hole 32, and the locker 30 is stored in front of the unload valve 21 in the locker mounting hole 32. It is done.
[0029]
A passage 28 communicating with the hydraulic power source and a passage 29 communicating with the tank 7 are formed in the valve housing 31, and the unload passage 22 is constituted by both the passages 28 and 29. The locker mounting hole 32 is formed so as to penetrate both the passages 28 and 29.
[0030]
The unload valve 21 includes a cylindrical member 33 that is inserted into the back of the locker mounting hole 32 of the valve housing 31, a spool 34 that is slidably inserted into the cylindrical member 33, and an open position of the spool 34. And a spring 35 urging in the direction. The cylindrical member 33 is formed with through holes 38 and 39 communicating with the passages 28 and 29 of the valve housing 31, and the spool 34 closes the through hole 39 in its closed position by the land portion 37. .
[0031]
The locker 30 locks the movement of the cylinder 42 with respect to the holder 41, a cylindrical holder 41 that is screwed into the locker mounting hole 32, a cylinder 42 that is slidably received in the holder 41, and the holder 42. A locking mechanism 45 and a key 40 for operating the locking mechanism 45 are provided.
[0032]
As shown in FIG. 2B, a key hole 43 into which the key 40 is inserted is opened on the base end surface of the cylinder 42. The front end surface of the cylinder 42 contacts the end of the spool 34. The locking mechanism 45 is unlocked when the key 40 is inserted into the keyhole 43, and can be moved in the axial direction together with the spool 34 while rotating the cylinder 42.
[0033]
A seal 47 is interposed between the cylinder 42 and the holder 41. The seal 47 seals between the cylinder 42 and the holder 41, thereby preventing the hydraulic oil from leaking through the lock device 30.
[0034]
A seal 49 is interposed between the pump housing 31 and the holder 41. The seal 49 seals between the pump housing 31 and the holder 41, thereby preventing the hydraulic oil from leaking through the lock device 30.
[0035]
Next, the operation of the embodiment of the present invention configured as described above will be described.
[0036]
At the start of operation of the construction machine, the key 40 is inserted into the key hole 43 to release the locking operation of the locking mechanism 45, and the cylinder 42 is moved in the axial direction while rotating to move the spool 34 from the illustrated open position to the spring 35. Push it into the closed position. As a result, the unload valve 21 closes the unload passage 22 to enable the travel hydraulic motor 1 to operate, and the vehicle travels normally.
[0037]
When the operation of the construction machine is stopped, the locking operation of the locking mechanism 45 is released by inserting the key 40 into the key hole 43, and the spool 34 is moved from the above-mentioned closed position by moving in the axial direction while rotating the cylinder 42. Switch to the open position. As a result, the unload valve 21 opens the unload passage 22 to disable the operation of the traveling hydraulic motor 1 and disable the traveling of the vehicle.
[0038]
Therefore, even if the engine key is unlocked and the engine 4 is driven, the vehicle cannot run unless the locker 30 is unlocked, and theft can be prevented.
[0039]
Since the unload valve 21 is opened and closed via the locker 30, even if the locker 30 is destroyed, the construction machine cannot be moved unless the unload valve 21 is switched to the closed position. For this reason, the hydraulic device of the construction machine cannot be easily restored by connection of hydraulic piping or the like, and a high antitheft effect can be obtained.
[0040]
In the present embodiment, since the unload passage 23 of the left traveling hydraulic motor 1 is opened via the lock device 30, even if the lock device 30 is broken, the unload valve 21 is not switched to the closed position. The hydraulic actuator cannot be moved.
[0041]
Further, since the locker 30 is housed in the locker mounting hole 32 of the valve housing 31 together with the unloading valve 21, in order to switch the unloading valve 21 to the closed position without using the key 40, the valve housing 31 itself is required. It takes a long time to remove it from the construction machine and disassemble it, and a high anti-theft effect is obtained.
[0042]
Further, when the unload valve 21 is removed together with the locker 30 from the valve housing 31, the pressurized hydraulic oil from the hydraulic pump 3 leaks to the outside, and the actuator cannot be driven.
[0043]
An unload passage may be provided so as to bypass the main relief valve 17, and an unload valve may be interposed in the middle of the unload passage.
[0044]
As another embodiment, as shown in FIG. 3, the first passage 11 that leads the pressurized hydraulic oil from the supply passage 5 to the left traveling hydraulic motor 1 when the unload passage 22 travels forward is short-circuited to the return passage 6. However, an unload valve 21 may be interposed in the middle of the unload passage 22.
[0045]
In this case, even if the locker 30 is destroyed, the left traveling hydraulic motor 1 cannot be moved unless the unload valve 21 is switched to the closed position. For this reason, even if the right traveling hydraulic motor 2 operates, the vehicle cannot go straight.
[0046]
As another embodiment, as shown in FIG. 4, an unload passage 23 that short-circuits the first passage 11 and the second passage 12 that communicate with the left traveling hydraulic motor 1 is provided, and in the middle of the unload passage 23. An unload valve 21 may be interposed.
[0047]
Also in this case, by opening the unload passage 23 of the traveling hydraulic motor 1 through the locker 30, the left traveling hydraulic motor 1 is not switched to the closed position even if the locker 30 is broken even if the unload valve 21 is switched to the closed position. Can not move.
[0048]
As another embodiment, as shown in FIG. 5, an unload passage 25 that short-circuits the supply passage 5 and the suction passage 8 may be provided, and an unload valve 21 may be interposed in the middle of the unload passage 25. .
[0049]
A pump housing 51 is mounted on the construction machine. In the pump housing 51, each switching valve 13, the main relief valve 17 and the unload valve 21 are interposed, and a locker 30 is interposed. That is, the pump housing 51 houses both the unload valve 21 that stops the flow of hydraulic oil guided to the traveling hydraulic motor 1 and the locker 30 that operates the unload valve 21.
[0050]
In this case, by opening the unload passage 25 through the locker 30, if the unload valve 21 is not switched to the closed position even if the locker 30 is broken, all the hydraulic actuators including the left and right traveling hydraulic motors are operated. I can't move it.
[0051]
Furthermore, since the locker 30 is housed in the pump housing 51 together with the unload valve 21, in order to switch the unload valve 21 to the closed position without using the key 40, the pump housing 51 itself is removed from the construction machine and disassembled. It takes a long time to work, and a high anti-theft effect is obtained.
[0052]
When the unload valve 21 is removed together with the locker 30 from the pump housing 51, the pressurized hydraulic fluid from the hydraulic pump 3 leaks to the outside, and the actuator cannot be driven.
[0053]
The present invention can also be applied to a hydraulic power source that includes two or more hydraulic pumps in an open circuit. In this case, the discharge pressures of all the hydraulic pumps do not necessarily have to be regulated by the locker. For example, when two hydraulic pumps are provided as the hydraulic power sources of the left and right traveling hydraulic motors, if the discharge pressure of one hydraulic pump is restricted by a locker, the vehicle cannot go straight and theft can be prevented.
[0054]
Further, as shown in FIG. 4, a shutoff valve 26 is interposed in the middle of the pipe constituting the first passage 11 connecting the switching valve 13 and the right traveling hydraulic motor 2, and this shutoff valve 26 is connected via a key 40. A locker 30 that is mechanically opened and closed is provided.
[0055]
In this case, the right traveling hydraulic motor 1 cannot be moved by closing the shutoff valve 26 via the locker 30.
[0056]
Next, another embodiment shown in FIG. 6 is provided with a shut-off valve 27 for shutting off the flow of hydraulic oil discharged from the hydraulic pump 3 on the downstream side of the relief valve 17 in the supply passage 5. A locker 30 that mechanically opens and closes via 40 is provided, and a shutoff valve 27 and a locker 30 that switches the lock valve 30 are housed in a valve housing 31.
[0057]
In this case, since the shut-off valve 27 is opened and closed via the locker 30, even if the locker 30 is broken, the construction machine cannot be moved unless the shut-off valve 27 is switched to the open position.
[0058]
When the locker 30 and the shutoff valve 27 are removed from the valve housing 31, the pressurized hydraulic fluid from the hydraulic pump 3 leaks to the outside, and the traveling hydraulic motors 1 and 2 cannot be driven. High anti-theft effect can be obtained.
[0059]
The present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a hydraulic circuit diagram of a theft prevention hydraulic device for a construction machine according to an embodiment of the present invention.
2A is a cross-sectional view of a valve housing and the like, and FIG. 2B is a side view.
FIG. 3 is a hydraulic circuit diagram of an antitheft hydraulic device showing another embodiment.
FIG. 4 is a hydraulic circuit diagram of an antitheft hydraulic device showing another embodiment.
FIG. 5 is a hydraulic circuit diagram of an anti-theft hydraulic device showing another embodiment.
FIG. 6 is a hydraulic circuit diagram of an antitheft hydraulic device showing another embodiment.
FIG. 7 is a hydraulic circuit diagram showing a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Travel hydraulic motor 3 Hydraulic pump 4 Engine 5 Supply path 6 Return path 21 Unload valve 22-25 Unload path 27 Shut-off valve 30 Locking device 31 Valve housing 32 Locking device mounting hole 40 Key 51 Pump housing

Claims (5)

In anti-theft hydraulic equipment for construction machinery,
An unloading valve that recirculates hydraulic oil that is directed to the actuator to the tank side via the switching valve for operation of the construction machine, a locker that mechanically opens and closes the unloading valve through a key, and a switching valve for the operation of the construction machine And a valve housing for storing the unloading valve and a locker for switching the valve housing in the valve housing, and operating the hydraulic pump by opening the unloading valve via a key when the construction machine is not in operation. A construction machine anti-theft hydraulic device characterized in that oil is not distributed to a construction machine operation switching valve. In anti-theft hydraulic equipment for construction machinery,
The pump includes an unload valve for returning hydraulic oil discharged from the hydraulic pump to the tank side, a locker that mechanically opens and closes the unload valve through a key, and a pump housing that houses the hydraulic pump. The housing is housed with an unloading valve and a locker that switches the unloading valve, and when the construction machine is not in operation, the unloading valve is opened via a key to switch the hydraulic oil from the hydraulic pump to the construction machine operation switching valve. An anti-theft hydraulic device for construction machinery, characterized in that it is configured not to circulate. In anti-theft hydraulic equipment for construction machinery,
A relief valve that returns the hydraulic oil discharged from the hydraulic pump to the tank side in response to an increase in the discharge pressure of the hydraulic pump, and a flow of hydraulic oil discharged from the hydraulic pump downstream of the relief valve. A shut-off valve for shutting off and a locker for mechanically opening and closing the shut-off valve via a key, and a shut-off valve and a locker for switching the shut-off valve are housed in a valve housing for storing a switching valve for operation of the construction machine. An anti-theft hydraulic device for construction machinery, characterized in that the shut-off valve is closed via a key during non-operation of the construction machine. The anti-theft hydraulic device for a construction machine according to claim 1 or 2, wherein the unload valve that is switched via the locker is interposed in the middle of hydraulic piping. The anti-theft hydraulic device for a construction machine according to claim 3, wherein the shut-off valve that is switched via the locker is interposed in the middle of hydraulic piping.

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