JP2003278187A - Antitheft device for hydraulic shovel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize an antitheft at an extremely low cost without newly adding a part as antitheft countermeasure or changing the equipment layout. <P>SOLUTION: This hydraulic shovel comprises an operating system change-over valve provided in a pilot line connecting a plurality of remote control valves to a plurality of hydraulic actuators, the operating system change-over valve being switchable between a plurality of switching positions. The operating system change-over valve 10 is constituted to interrupt the connection between the remote control valves and the hydraulic actuators in a state where it is operated to a non-switching position out of each switching position. This hydraulic shovel further comprises retaining means 10e, 10h and 14 for retaining the change-over valve 10 in the non-switching position. <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 an antitheft device for preventing theft of a hydraulic excavator.

[0002]

2. Description of the Related Art Usually, a hydraulic excavator is moved by a trailer, so that only the hydraulic excavator is often left at the work site at night or on holidays when work is not performed. In such a situation, the hydraulic excavator is often stolen at a work site or the like that is hard to be noticed.
Therefore, the anti-theft device is usually mounted on the hydraulic excavator.

Various anti-theft devices of this type have been proposed in the past.

For example, the one disclosed in Japanese Unexamined Patent Publication No. 9-50584 makes it impossible to operate the shovel by shutting off the primary side and the secondary side of the pilot pressure when parked, and is provided in the cab. If you enter your password through the numeric keypad, the block will be released.

The device disclosed in Japanese Unexamined Patent Publication No. 10-19619 prevents the transport using a trailer by locking the upper revolving structure while rotating it with respect to the lower traveling structure by a predetermined angle when parked. It has become. In addition, when unlocking, like the former one, the personal identification number is input through the ten keys.

[0006]

However, when the above-mentioned conventional anti-theft device is introduced, an input device such as a numeric keypad, a controller for collating a number input from the numeric keypad, a control valve for shutting off or communicating the pilot pressure. In addition to the new addition, the valve must be controlled by the controller, which inevitably increases the cost of the hydraulic excavator.

Further, in a device using a numeric keypad, the antitheft device can be easily found by tracing the cable connected to the device.

Furthermore, in the mini excavator having almost no extra space in the upper swing body, there is a problem that the equipment layout must be changed in order to arrange the antitheft device.

The present invention has been made in consideration of the above-mentioned problems in the conventional antitheft device, and does not require any new addition of a dedicated part as the antitheft device and does not change the device layout, and (EN) An antitheft device for a hydraulic excavator that can realize antitheft at low cost.

[0010]

According to the present invention, an operation mode switching valve is provided in a pilot line connecting a plurality of remote control valves and a plurality of hydraulic actuators, and the operation system switching valve is switched between a plurality of switching positions. In the hydraulic excavator configured as described above, the connection between the remote control valve and the hydraulic actuator is cut off when the operation mode switching valve is operated to the non-switching position outside each switching position, and the switching method is the same. The anti-theft device for a hydraulic excavator is provided with a holding means for holding the valve in the non-switching position.

The operation mode switching valve of the hydraulic excavator is configured to switch the operation pattern of each hydraulic actuator on the upper swing body including the swing motor, boom cylinder, arm cylinder, and bucket cylinder.
Usually, in addition to the standard operation method conforming to ISO, three other operation methods (corresponding to H company, M company, and K company) are added,
There are four operation methods in total.

According to the present invention, when the operation mode switching valve is held in the non-switching position other than the switching position by the holding means, the input port and the output port are shut off and the operation of each hydraulic actuator on the upper swing body is locked. It Even if each actuator on the upper swing body is locked, the lower traveling body can operate. However, when the shovel is parked, the bucket is normally grounded, and therefore the traveling is substantially impossible unless the front attachment can be raised. Further, in the state where the front attachment is set up, even if the trailer can be loaded, for example, the total height becomes high, and therefore it is impossible to drive on a public road. In this way, the new idea of holding the operation mode switching valve in the non-switching position makes it possible to prevent theft without introducing a new device or changing the device layout.

In the present invention, if the holding means is composed of a fixing hole provided in the operation lever of the operation mode switching valve and a fixing screw penetrating the fixing hole and screwed into the main body of the switching valve. Therefore, the operation mode switching valve can be reliably held in the non-switching position even in an environment where vibration is applied to the machine body.

In the present invention, the holding means includes holes provided in correspondence with the operation lever of the operation mode switching valve and the body of the switching valve, and a lock for locking the holes by latching the holes. With this configuration, even if it is realized that the operation mode switching valve is used for anti-theft, the holding of the non-switching position cannot be released unless the key is unlocked, so that the anti-theft effect is further enhanced. be able to.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below in detail based on the embodiments shown in the drawings.

FIG. 1 is a side view of a hydraulic excavator to which the anti-theft device of the present invention is applied.

In the figure, 1 is a lower traveling body, 2 is an upper swing body, 3 is a boom, 4 is an arm, 5 is a bucket, and these are operated by a boom cylinder 6, an arm cylinder 7, and a bucket cylinder 8, respectively. It

Reference numeral 9 denotes an operator's cab provided in the front part of the upper swing body 2.

In this embodiment, the operation mode switching valve 10 shown in FIG. 2 is arranged below the floor in the operator's cab 9. When the floor mat 11 is removed and the cover 12 is removed, the operation mode switching valve 10 is removed. The operation lever 10a is exposed.

FIG. 3 shows the structure of the operation mode switching valve 10. (a) is a plan view, (b) is a front view, and (c) is (b).
It shows a cross-sectional view taken along the line AA in the figure, that is, a cross-sectional view of the input ports I _{1 to} I ₈ .

In FIG. 3, the operation mode switching valve 10 is provided in a pilot line connecting a plurality of operation remote control valves and respective pilot ports of a plurality of hydraulic actuators, and input ports I _{1 to} I _{8 are provided.} The operation pattern can be switched by switching the connection relationship between the oil passages O _{1 to} O ₈ (see FIG. 3C) and the oil passages communicating with the output ports. In the figure, the oil passages leading to the input port and the output port face each other and are in communication.

A rotary pool 10c is inserted in the casing 10b, and is rotated by a predetermined angle (45 °) by operating the operating lever 10a so that any one of the _four switching positions P _{1 to} P ₄ can be obtained. You can choose.

Incidentally, P ₁ is a standard operation pattern according to ISO, P ₂ is an operation pattern of H company, P ₃ is an operation pattern of M company, and P ₄ is an operation pattern of K company.

[0024] The rotation center of the operation lever 10a is formed with a disc portion 10d, in the disk portion 10d in correspondence with the switching position P ₁ to P ₄ 4 single fixing holes S ₁ to S ₄ Are arranged on the circumference. For example, the fixing hole S ₁ is provided at a position displaced by 90 ° clockwise from the switching position P ₁ .

These fixing holes S _{1 to} S ₄ are for fixing the operation lever 10a at each switching position, and the operation lever 10a is carelessly rotated so that the operation pattern and the operation of the machine do not match. To prevent it from becoming. 13 is a thumbscrew, which is inserted into any one of the fixing holes S _{1 to} S ₄ ,
It is adapted to be screwed onto the upper surface of the casing 10b. The fixing holes S _{1 to} S ₄ and the thumbscrew 13 are conventionally provided in the operation mode switching valve 10.

In this embodiment, a fixing hole S ₅ is newly added in addition to the fixing holes S _{1 to} S ₄ .

This fixing hole S ₅ is, as shown in FIG. 4 (c),
It is provided between S ₁ and S ₂ and this intermediate position is shown in FIG.
As shown in (a), this corresponds to the non-switching position L in which the operating lever 10a is rotated 22.5 ° counterclockwise from the switching position P ₁ .

FIG. 4 (b) shows the arrangement of the oil passage leading to the input port and the output port when the operating lever 10a is in the non-switching position L.

At the non-switching position L, the input port (for example, I ₁ ) and the oil passage (O ₁ ) are shut off. In this state, if the thumbscrew 13 is inserted into the fixing hole S ₅ and screwed onto the upper surface of the casing 10b, the pilot line communicating from the operation remote control valve to each pilot port of the plurality of hydraulic actuators is cut off. The front attachment cannot be operated and the upper revolving structure cannot be swiveled.

The thumbscrew 13 and the fixing hole S ₅ function as holding means for holding the operation mode switching valve 10 in the non-switching position.

Further, FIG. 5 shows a structure in which the operating lever 10a is locked at the non-switching position L.

In the figure, the lever arm 10e of the operating lever 10a is provided with a through hole 10f.

When the operating lever 10a is in the non-switching position L, the through hole 10 is provided below the lever arm 10e.
A locking collar 10h provided with g is provided. The locking collar 10h is provided so as to project from the side wall of the casing 10b.

Reference numeral 14 denotes a commercially available cylinder lock, which is locked by inserting the latch 14a into the cylinder body 14b through the through holes 10f and 10g.

Operation lever 10 having the through hole 10f
The locking collar 10h provided with a, the through hole 10g, and the cylinder lock 14 function as holding means.

If the cylinder lock is used in this way, the operating lever 10a cannot be rotated to the switching position even if it is understood that the operating method switching valve 10 is used as a theft prevention means. It is possible to more reliably prevent theft.

It is to be noted that the lock is not limited to the cylinder lock having the above-mentioned key inserted therein, and, for example, a lock having a combination of personal identification numbers by rotating a plurality of number rings can be used.

[0038]

As is apparent from the above description,
According to the first aspect of the present invention, the operation mode switching valve is held in the non-switching position other than the switching position, the input port and the output port are shut off, and the operation of each hydraulic actuator on the upper swing body is locked. Since it is configured, it is possible to operate the undercarriage, but when parking the shovel,
Usually, since the bucket is grounded, it is practically impossible to drive unless the front attachment can be raised, and with the front attachment set, for example, the total height will be high even if it can be loaded on the trailer. It will be impossible to drive on public roads. This makes it possible to inexpensively prevent theft without introducing a new device or changing the device layout.

In addition, the operation mode switching valve is usually placed below the floor or inside the body cover, is invisible, and locks the hydraulic pressure at a portion that cannot be imagined by an outsider, so that a sufficient antitheft effect is obtained. Can be obtained.

According to the second aspect of the present invention, the holding means is fixed to the fixing hole provided in the operation lever of the operation mode switching valve, and the fixing means screwed through the fixing hole to the main body of the switching valve. Since it is configured with screws, the operation mode switching valve can be reliably held in the non-switching position even in an environment where vibration is applied to the machine body.

According to the third aspect of the present invention, the holding means is provided with holes provided in correspondence with the operation lever of the operation mode switching valve and the body of the switching valve, and a latch is provided on the holes. Since it is configured with a lock that locks through, even if it is understood that the operation method switching valve is used as anti-theft, it can not release the holding of the non-switching position unless the key is unlocked. The prevention effect can be further enhanced.

[Brief description of drawings]

FIG. 1 is an overall view of a hydraulic excavator to which an anti-theft device of the present invention is applied.

FIG. 2 is a perspective view showing an arrangement of an operation mode switching valve of the present invention.

3A is a plan view of an operation mode switching valve, FIG. 3B is a front view, and FIG. 3C is a sectional view taken along line AA in FIG. 3B.

4A is a plan view of an operation mode switching valve, FIG. 4B is a cross-sectional view showing an arrangement of input ports and output ports in a non-switching position,
(c) is a plan view showing a configuration of an operation lever.

FIG. 5 is an explanatory view showing locking of the operating lever using a cylinder lock.

[Explanation of symbols]

1 Undercarriage 2 Upper revolving structure 3 boom 4 arms 5 buckets 10 Operation method switching valve 10a operating lever 10b casing 10c rotary spool 10d disk part 10e lever arm 10f through hole 10g through hole 10h Locking collar

Claims (3)

[Claims] 1. A hydraulic excavator configured such that a pilot line connecting a plurality of remote control valves and a plurality of hydraulic actuators is provided with an operation mode switching valve, and the operation system switching valve is switched between a plurality of switching positions. When the operation mode switching valve is operated to a non-switching position outside the switching positions, the remote control valve and the hydraulic actuator are disconnected, and the switching valve is set to the non-switching position. An antitheft device for a hydraulic excavator, which is provided with a holding means for holding at a position. 2. The holding means comprises a fixing hole provided in an operation lever of the operation mode switching valve, and a fixing screw penetrating through the fixing hole and screwed into the main body of the switching valve. Anti-theft device for hydraulic excavators. 3. The holding means comprises hole portions provided corresponding to the operation lever of the operation mode switching valve and the main body of the switching valve, and a lock that locks by locking a latch in the hole portions. The anti-theft device for a hydraulic excavator according to claim 1.