JPS5849665B2 - Earthmoving machine safety equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a safety device that supports a lift arm that is attached to an earth-moving machine such as a shovel device.

Generally, when servicing engines such as tractor excavators,
This is done by raising and stopping the lift arm to the highest position.

In order to prevent unexpected descent at this time, there is a known means for preventing descent using a safety pin, which is disclosed in Japanese Utility Model Publication No. 465073.

In this known example, the lift arm elevation operation lever is locked in conjunction with the insertion and removal of the safety pin, but this interlocking system is connected by a mechanical link means, so it cannot be used independently. There is a drawback that the lift arm elevation control lever cannot be locked or released.

In other words, when the lift arm naturally descends and the weight is on the safety pin, it is impossible to remove the safety pin with artificial force, so it is necessary to lift the lift arm upward to remove the weight on the safety pin. To do this, it is necessary to operate the lift arm elevation control lever to move the lift arm from the holding position to the raised position.

In the case of the above-mentioned known example, since the locking mechanism and the safety bottle are connected by a link mechanism, it is not possible to release the locking mechanism alone.

Furthermore, it is also not possible to lock only the lift arm elevation operation lever.

The present invention aims to improve such drawbacks, and includes a safety pin insertion/extraction link mechanism near the safety pin device position, and connects the mechanism to the locking mechanism of the lift arm lifting/lowering operating lever via a cable. After being connected, the locking action is performed in conjunction with the insertion of the safety pin, so that the lift arm elevation control lever can be locked and released regardless of whether the safety bin is inserted or removed. .

The explanation will be given below with reference to the embodiment figures.

10 shows a side frame (only one side shown) of a tractor shovel, and the base end of a lift arm 11 (only one side shown) is supported by a pivot 12.

This lift arm 11 is connected to a telescopic rod 14 of a lift cylinder 13 provided on the side surface of the side frame 10, and is swung up and down.

Pressure fluid is selectively supplied to the lift cylinder 13 through a hydraulic pressure control valve (not shown) operated by the lift arm elevating operation lever 15, and the telescopic rod 14
The lift arm 11 is controlled to extend and contract, and the lift arm 11 is raised, lowered, held, and floated.

The above is conventionally known.

In such preparations, a safety pin insertion/removal link mechanism is provided to prevent unexpected lowering when the lift arm 11 is raised to near the highest position and kept in a stopped state in order to maintain the engine.

Details below. 16 indicates a safety pin, lift arm 1
1 is provided at a position that interferes with the arm base 17 when the arm is raised near the maximum raised position.

For this purpose, a safety pin holding bracket 18 that horizontally crosses the side frame 10 is fixed to the front inner side of the side frame 10, and the safety pin 16 is slidably inserted so that it can go in and out from the side frame 10 to the outer surface. Make it.

A safety pin insertion/extraction link mechanism is provided so that the safety pin 16 can be operated in and out from the driver's seat.

This link mechanism can be freely swung by fixing a bracket 20 having a support shaft 19 to the front wall of the driver's seat, and pivoting a rotary cylinder part 23 to which a manual handle 21 and a first interlocking lever 22 are fixed. On the other hand, a transmission lever 25 is suspended from the lower surface of the crossbar 24 passed between the side frames 10 so as to be able to swing freely in the horizontal direction, and one end of the transmission lever 25 is connected to the first interlocking lever 2.
2 and the rod 26, and the other end is connected to the safety bin 1.
6 and is freely connected by a rod 27.

Thus, by operating the handle 21, the transmission lever 25 is swung, and the safety pin 16 can be inserted or removed from the driver's seat.

The present invention further includes an interlocking locking means that locks the lift arm lifting/lowering operating lever 15 in the holding position in conjunction with the insertion of the safety pin 16.

For this purpose, the second interlocking lever 28 was fixed to the rotating cylinder part 23 of the safety pin insertion/extraction link mechanism, one end of the cable 29 was connected, and the manual lever 21 was swung in the counterclockwise direction of the safety pin insertion. Finally, the cable 29 is pulled to engage the locking mechanism 30.

A locking mechanism 30 locks a lift arm lifting/lowering operating lever 15 at a holding position to prevent it from moving, and prevents the lever 15 from moving to a lift arm lowering position even if it is inadvertently touched.

Furthermore, even if the user forgets to remove the safety pin 16 and attempts to move the lever 15 to the lift arm lowering position, the lever 15 cannot be moved.

In detail below, 15 shows a lift arm elevating operation lever, and a rotating shaft 3 rotatably supported on a bracket 31.
It is pivotally mounted 33 to the tip of 2 so as to swing in the vertical direction.

A lockper 34 and a lever 35 are integrally provided on the pivot base side of the lift arm elevating operation lever 15 in the vertical direction.

A rod 36 is connected to the lever 35 and connected to a lift arm lifting/lowering hydraulic pressure control valve (not shown), and the control valve is switched according to the upper, lower, lower, or floating positions of the lift arm lifting/lowering operation lever 15.

One lockper 34 is designed to engage with the locking mechanism 30 when the lift arm lifting/lowering operating lever 15 is set at the holding position, thereby keeping the operating lever 15 at the holding position.

The locking mechanism 30 has a support shaft 38 fixed to a bracket 37 and a rotatable cylindrical shaft 39 pivotally connected thereto, and a manual handle 40 and a restraining bar 4 that engages with the lock lever 34 on the cylindrical shaft 39.
1 is provided so that the scale can swing freely, and the swinging position is determined by an urging spring 42.

When the manual handle 40 is swung counterclockwise, the restraining bar 41 is engaged with the locking member 34, and when the manual handle 40 is swung clockwise, it is disengaged.

In order to achieve a locking effect in conjunction with the insertion of the safety pin 16, a link 43 is provided on the cylindrical shaft 39, and a cable link lever 44 is pivotally supported on the support shaft 38, so that the other end of the cable 29 can be locked. are connected so that the movement of the manual lever 40 for inserting and removing the safety pin is linked.

The link 43 includes a lever 45 fixed to the cylindrical shaft 39, a rod 46 connected to the lever 45 at one end, and a link joint 47 connected to the cable link lever 44 to slidably hold the other end of the rod 46. and a stopper 48 at the end of the rod 46.

Then, when the manual lever 21 for operating the safety bin is swung counterclockwise to insert the safety pin, and the second interlocking lever 28 is pulled to pull the cable 29 to the right in the figure, the cable interlocking lever 44 is activated. It is swung counterclockwise.

In this swinging motion, the linkage joint 47 hits the stopper 48 and swings the rod 46, causing the lever 45 to swing counterclockwise.

Therefore, since the cylinder shaft 39 is rotated, the restraint bar 41 is also swung, and the lift arm elevating operation lever 15, which is in the retained position, is rotated.
This will engage the locking par 34 of.

In this way, the insertion of the safety pin 16 can be linked to the locking action of the holding position of the lift arm lifting/lowering operating lever 15.

When the manual knob 40 of the locking mechanism 30 is swung counterclockwise from the free position A to the lock position B, the rod 46 that is attached to the link 43 slides against the link joint 47. Therefore, the cable interlocking lever 44 cannot be rotated and the safety pin 16 is not inserted in the locking direction and does not slide.

Therefore, only the lift arm raising/lowering operation lever 15 can be locked independently.

Further, when the manual lever 21 for operating the safety pin is swung to the free position C for removing the safety pin, the second interlocking lever 28 pushes the cable 29 and swings the cable interlocking lever 44 clockwise, but the linking joint 47 The lever 40 cannot be returned from the locked position B to the free position A by sliding it on the parrod 46 and locking it manually.

Therefore, even if the safety pin 16 is removed, the lift arm elevation operation lever 15 will not be unlocked, and the lift arm 16 can be lowered after confirming safety.

The present invention further includes a lock releasing means that can move the lift arm elevation operating lever 15 only from the locked state of the fixed position to the raised position.

For this purpose, the restraining bar 41 of the locking mechanism 30 has a groove 50.
An engagement hole 51 is provided perpendicular to the groove 50, and a stepped protrusion 52 is provided on the lock par 34 so as to engage with the groove 50 button and the engagement hole 51.

A spring 53 is provided between the stopper 48 of the button 46 of the link 43 and the link joint 47.

Thus, when the lift arm elevating operation lever 15 is in the holding position, the stepped protrusion 52 of the locking member 34 is pressed against the restraining bar 41.
When the manual locking lever 40 is swung from the lock position B toward the free position A while the rod 46 is inserted into the engagement hole 51 and locked, the rod 46 compresses the spring 53 and absorbs the amount of swiveling.

Therefore, the restraining bar 41 swings clockwise by the spring compression amount and is disengaged from the stepped projection 52 of the locking member 34.

Therefore, the lift arm raising/lowering operation lever 15 can be moved only to the lift arm raised position by being guided by the locking member 34 that engages along the groove 50 of the restraining bar 41.

This structure and action is because when the lift arm 11 naturally descends and the weight is applied to the safety pin 16, the safety pin 16 cannot be pulled out by input, so it is necessary to raise the lift arm 11 once. It arises.

As described above, the present invention is capable of locking a lift arm elevating operation lever in conjunction with insertion of a safety pin, and temporarily releasing the locking mechanism when the safety pin is inserted. The locking mechanism can be locked and unlocked regardless of whether the casing or the safety pin is inserted or removed, making it more functional and safer than conventional devices.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a side view;
FIG. 2 is a plan view, FIG. 3 is an explanatory diagram of the main part structure, and FIGS. 4 and 3 are sectional views taken along the line IV-IV. 11 is a lift arm, 15 is an operating lever, 16 is a safety bin, 29 is a cable, 30 is a locking mechanism, and 43 is an associated link.

Claims (1)

[Claims] 1. A safety pin 16 is slidably provided on a holding bracket 18 fixed to the frame to engage the lift arm 11 in the raised state by protruding.
A manual handle 21 that reciprocates the safety pin 16 is connected via a link mechanism, and the operating lever 15 is locked in the retained position near the pivot point of the operating lever 15 that raises and lowers the lift arm 11. A locking mechanism 30 is provided, which consists of a deterrent lever 41 that operates the deterrent lever 41 and a manual handle 40 that operates the deterrent lever 41.A locking mechanism 30 is provided with a locking cable that operates the deterrent lever 41 in the locking direction via a spring 53. An interlocking lever 44 is provided, and the cable interlocking lever 44 and a link mechanism for operating the safety pin 16 are connected to the cable 2.
A safety device for an earthmoving machine characterized by being connected at 9.