JPH072599B2 - Industrial vehicle cargo handling equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a cargo handling device for industrial vehicles.

2. Description of the Related Art As is well known in some industrial vehicles, a carriage to which various attachments such as forks are attached is moved up and down along a guide mast that is erected at the front of the vehicle body by expanding and contracting a lift cylinder. It is known to have a cargo handling device as described above. This cargo handling device basically operates the lift control lever to set the lift control valve from the neutral position to the raised position, and hydraulic oil is supplied from the hydraulic pump into the lower liquid chamber of the lift cylinder to lift the piston of the lift cylinder. As it moves upward, the hydraulic oil in the upper liquid chamber of the lift cylinder is pushed by the piston and returns to the reservoir tank,
The lift cylinder extends. On the contrary, when the lift control valve is operated from the neutral position to the lowered position by operating the lift control lever, the hydraulic oil in the lower liquid chamber of the lift cylinder is pushed out by the piston receiving the load from the carriage and the reservoir tank At the same time, the lift cylinder is contracted by replenishing part of the hydraulic oil returning from the hydraulic pump side to the reservoir tank with the hydraulic oil returning to the reservoir tank to the upper liquid chamber of the lift cylinder. ing.

Problems to be Solved by the Invention Since the lifting speed of the carriage, that is, the expansion / contraction speed of the lift cylinder is adjusted by the opening of the lift control valve, a high degree of proficiency is required to operate the lift control lever. . Especially when stacking cargo such as corrugated cardboard and broken pieces, when the carriage that has been unloaded is lowered and various attachments, pallets, etc. approach the lower luggage as the unloading position, the lowering speed of the carriage should be as high as possible. The lift control valve must be carefully operated so that it does not slow down and damage or collapse the lower load from a fork or pallet collision.

Therefore, an unloading position sensor is installed on the carriage including various attachments, and while the carriage is descending, the unloading position sensor is detected when various attachments, pallets, etc. come close to the lower baggage as the unloading position for the required distance. By operating the carriage, it is possible to automatically reduce the descending speed of the carriage without variation due to individual differences of the driver, so that the cargo handling work can be efficiently performed. However, when the unloading position sensor is attached to various attachments, the irradiation field of the unloading position sensor is likely to be blocked by the load or pallet loaded on the carriage. If the irradiation field of the unloading position sensor is blocked, the descending speed of the carriage is unnecessarily slowed down,
Cargo handling becomes difficult. Therefore, the unloading position sensor is attached so as to project downward from the carriage, and the unloading position sensor is set by projecting below the various attachments to prevent the unloading position sensor from malfunctioning and The distance to the unloading position can be measured accurately. However, if the unloading position sensor projects below the various attachments, the unloading position sensor interferes with the road surface before the carriage is lowered to the lowest position.

Therefore, the present invention provides a cargo handling device for an industrial vehicle, which can prevent road surface interference of the unloading position sensor and overcome the above problems.

A means for solving the problem A support member is movably mounted on a carriage that is vertically moved along a guide mast and various attachments such as forks are assembled, and a load is attached to a lower end of the support member, which projects downward from the carriage. While the unloading position sensor is provided and a protrusion is provided above the unloading position sensor of the supporting member, the guide mast is provided with a stopper that abuts on the protrusion and moves the supporting member upward when the carriage descends.

Action When the carriage is lowered from a position where the carriage is lifted above a predetermined lifting height, an unloading position sensor protruding downward from various attachments measures the distance between the carriage and the unloading position. Further, when the descending carriage is below a preset predetermined elevation, the projection contacts the stopper and the support member moves upward, thereby preventing the unloading position sensor from interfering with the road surface.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

As shown in FIGS. 1 to 5, in the cargo handling apparatus of this embodiment, a pair of left and right guide masts 3 composed of an inner mast 1 and an outer mast 2 are erected on the front part of the vehicle body S. The carriage 5 to which the fork 4 as an attachment is assembled is mounted so as to be able to move up and down. The lift cylinder 6 is inserted into the cylinder tube 6a and the cylinder tube 6a so as to be slidable in the axial direction and the upper liquid chamber 6b. The cylinder tube includes a piston 6d that defines the lower liquid chamber 6c, and an operating rod 6e that is connected to the piston 6d and axially slidably and sealingly penetrates the head wall of the cylinder tube 6a. The bottom part of 6a is fixed to the lower part of the outer mast 2, and the head part of the operating rod 6e is connected to the upper part of the inner mast 1. The chain wheel 7 is attached to the head part of the operating rod 6e. The one end of the lift chain 8 wound around the chain wheel 7 is moored to the cylinder tube 6a, and the other end of the lift chain 8 is moored to the carriage 5. By operating the lift control lever 9 to move up and down along the guide mast 3, the lift control valve 10 is moved to the neutral position 10a.
When the hydraulic pump 11 is set to the ascending position 10b, the hydraulic fluid is supplied from the hydraulic pump 11 into the lower fluid chamber 6c of the lift cylinder 6 to move the piston 6d upward and the hydraulic fluid present in the upper fluid chamber 6b is pushed by the piston 6d. When the lift cylinder 6 is extended to return to the reservoir tank 12, the lift cylinder 6 extends, and conversely, by operating the lift control lever 9,
When the lift control valve 10 is set from the neutral position 10a to the lower position 10c, the hydraulic oil in the lower liquid chamber 6c of the lift cylinder 6 is pushed out by the piston 6d receiving the load from the carriage 5 and returns to the reservoir tank 12, A part of the hydraulic oil returning to the reservoir tank 12 from the hydraulic pump 11 side together with the hydraulic oil returning to the reservoir tank 12 is replenished in the upper liquid chamber 6b of the lift cylinder 6, so that the lift cylinder 6 performs a contracting operation. The basic structure such as points is the same as the known structure.

Here, the cargo handling apparatus of this embodiment includes the flow rate adjusting mechanism 13 and the unloading position sensor 14. When the unloading position sensor 14 senses the unloading position A while the carriage 5 is descending, the flow rate is detected by this sensing operation. By lowering the adjusting mechanism 13 from the maximum flow rate to the minimum flow rate, the descending speed of the carriage 5 is reduced. Flow rate adjustment mechanism 13 is a variable throttle
It is provided with 15, an actuator 16 and a check valve 17. The variable throttle 15 is located at the bottom port 6f of the lift cylinder 6 and the lower position 10 of the lift control valve 10.
It is provided in the middle of the hydraulic line 18 connecting the descending port 10d in c. The actuator 16 is connected to a valve movable part (not shown) of the variable throttle 15, and the variable throttle 15 is changed from the maximum flow rate to the minimum flow rate by the drive current supply from the battery (not shown) accompanying the sensing operation of the unloading position sensor 14. Valve closing operation and the unloading position sensor 14
The variable throttle 15 is opened so that the flow rate is changed from the minimum flow rate to the maximum flow rate by shutting off the drive current from the battery due to the non-sensing operation. The check valve 17 is arranged in parallel with the variable throttle 15 in the middle of the hydraulic line 18, and allows only the flow of hydraulic oil flowing from the lift control valve 10 to the lift cylinder 6 side. On the other hand, the carriage 5 has a pair of left and right lift brackets 20 having rollers 19 on its outer surface that are slidably contacted with and engaged with the inner mast 1, and a fork 4 as a variety of attachments that is laterally mounted on the front portion thereof.
And the upper and lower finger bars 21 assembled with.
A support member 23 is vertically movably attached to the carriage 5. The support member 23 is inscribed in a tubular guide member 24 fixed to the inner surface of one of the pair of left and right lift brackets 20 so as to be slidably contactable and engageable in the vertical direction. Carriage 5 of this support member 23
An unloading position sensor 14 is provided via a bracket 25 at the lower end projecting downward. The irradiation field 14a of the unloading position sensor 14 is set toward the front of the carriage 5. A protrusion 26 is provided above the unloading position sensor 14 of the support member 23 so as to face radially outward. This protrusion
Reference numeral 26 is a vertical hole formed in the rear portion of the peripheral wall of the guide member 24.
It is inserted in 27. A spring 29 is provided so as to straddle a tip portion of the protrusion 26 protruding from the vertical hole 27 and a stud 28 protruding below the guide member 24 of the one lift bracket 20. The spring 29 biases the support member 23 downward. The spring 29 causes the protrusion 26 to come into contact with the lower end of the vertical hole 27, so that the unloading position sensor 14 is disposed below the carriage 5 with a required protrusion amount L from the lower surface of the fork 4. Further, the guide mast 3 is provided with a stopper 30. This stopper 30 is fixed to the lower part of the inner mast 1, and the unloading position sensor 14
Of the supporting member 23 while the carriage 5 descends from the predetermined height position to the lowest position while contacting the protrusion 26 at the predetermined height position on the way of lowering the carriage 5 which is more than the protrusion amount L from the lower surface of the fork 4. It is designed to move upward against the resilience of the spring 29. The predetermined lifting height H of the carriage 5 is set to be larger than the protrusion amount L of the unloading position sensor 14 from the lower surface of the fork 4 (H> L).

According to the structure of the above embodiment, as shown by the phantom line in FIG. 4, the lift control valve 10 is operated by operating the lift control lever 9 while the carriage 5 loaded on the fork 4 is lifted up.
From the lower port 10c to the lower position 10c, the hydraulic oil in the lower liquid chamber 6c of the lift cylinder 6 is pushed by the piston 6d receiving the product load G of the carriage 5 to open the maximum flow rate from the bottom port 6f. It is discharged to the reservoir tank 12 via the diaphragm 15 and the lift control valve 10, and the carriage 5 descends at a normal speed. Then, as shown by the solid line in FIG. 4, when the unloading position sensor 14 protruding downward from the lower surface of the fork 4 detects and senses the upper part of the lower baggage as the unloading position A, the flow rate adjusting mechanism is detected.
The variable throttle 15 of 13 is closed to the minimum flow rate by the actuator 16, the flow rate of the hydraulic oil flowing from the lift cylinder 6 to the lift control valve 10 side is reduced, and the descending speed of the carriage 5 is reduced. When the load of the carriage 5, which is decelerated to a slight speed and is lowered, is softly attached to the lower load as the unloading position A, the lift control lever 9 is operated to move the lift control valve 10 to the lower position.
After setting the neutral position 10a from 10c and stopping the descent of the carriage 5, the vehicle is retracted and the forks 4 are pulled out from the pallet of the load, whereby the unloading is completed.

Further, as indicated by a phantom line in FIG. 1, when the carriage 5 is lowered from a state where the carriage 5 is lifted up to a predetermined lift height H or more, when the carriage 5 reaches a predetermined lift position, it is indicated by a solid line in the figure. Thus, the protrusion 26 contacts the stopper 30. Then, when the carriage 5 is lowered, the protrusion 26 and the stopper 30
With the contact with the support member 23, the support member 23 moves upward against the elastic force of the spring 29, and the unloading position sensor 14 starts moving upward. When the carriage 5 is further lowered to the lowest position as shown in FIG. 5, the unloading position sensor 14 is pulled upward from the lower surface of the fork 4.
That is, while the carriage 5 is descending from the predetermined elevation position to the lowest descent position, the abutment of the projection 26 and the stopper 30 causes the support member 23 to move upward, and thus the load of the support member 23 as the support member 23 moves upward. The unloading position sensor 14 moves upward to prevent interference with the road surface D.

Furthermore, by operating the lift control lever 9,
When the lift control valve 10 is switched from the neutral position 10a to the lift position 10b, hydraulic fluid from the hydraulic pump 11 lifts the lift control valve 10 and the check valve 1.
Since the liquid is supplied to the lower liquid chamber 6c of the lift cylinder 6 via 7, the carriage 5 is raised at a normal speed. During this ascent, while the carriage 5 rises from the lowest position to the predetermined elevation position, the spring 29 biases the
The support member 23 moves downward as the carriage 5 rises, and thus the unloading position sensor 14 also moves downward. Then, when the carriage 5 rises above the predetermined elevation position, the protrusion 26 is formed into the vertical hole 27.
Then, the unloading position sensor 14 automatically returns to the state in which the unloading position sensor 14 is projected with the amount L of projection from the lower surface of the fork 4.

In the above-described embodiment, the support member 23 is configured to be slidable in the vertical direction, but the support member 23A is provided with the hinge 31 on the inner surface of the lift bracket 20, as shown in FIG. The unloading position sensor 14 is connected to the lower end of the support member 23A protruding downward from the carriage 5.
And the unloading position sensor 14 of the support member 23A.
Even if the protrusion 26 is provided on the upper side, the supporting member 23A is biased downward by the spring 29A, and the supporting member 23A is moved up and down about the hinge 31. .

As described above, according to the present invention, when stacking luggage,
Since the unloading position sensor operates when the carriage that is unloading and descending approaches the lower tier as the unloading position, the carriage descending speed should be automatically reduced without variation due to individual differences of the driver. You can
Moreover, since the irradiation field of the unloading position sensor is not blocked by the cargo loaded on the carriage, malfunction of the unloading position sensor can be prevented, and the distance between the carriage and the unloading position can be accurately measured. be able to. Further, while the carriage is descending, the protrusion of the supporting member and the guide mast contact each other, so that the unloading position sensor can be moved and arranged upward, and interference between the unloading position sensor and the road surface can be prevented. There is a new effect that work can be performed efficiently.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of the present invention, FIG. 2 is a schematic configuration diagram of the same embodiment, FIG. 3 is a rear perspective view showing a carriage of the same embodiment, and FIGS. And FIG. 6 is a rear perspective view of a carriage showing a different example of the present invention. 3 ... Guide mast, 4 ... Fork (various attachments), 5 ... Carriage, 14 ... Unloading position sensor, 14a ... Irradiation field, 23, 23A ... Supporting member, 26 ... Protrusion, 30 ... Stopper, L ... Projection amount, H ... Predetermined lift.

Claims (1)

[Claims] 1. A support member is vertically movably attached to a carriage to which various attachments such as forks are assembled by being moved up and down along a guide mast, and an unloading position sensor is provided at a lower end of the support member protruding downward from the carriage. And a protrusion is provided above the unloading position sensor of the support member, while the guide mast is provided with a stopper that abuts on the protrusion and moves the support member upward while the carriage is descending. Industrial vehicle cargo handling equipment.