JPH02291397A - Cargo gear of lift truck - Google Patents

Abstract

PURPOSE:To easily position an attachment in the forward direction and right and left directions by installing an attachment support member on a forward base member in such a manner as to turn horizontally, and providing the first and second cylinders rotatably on the support member. CONSTITUTION:An attachment support member 22 is supported on a base member 18 through the first cylinder 30 and the second cylinder 32. The attachment support member 22 side supporting points of the first and second cylinders have designated phase angles to the rotational center 20. Accordingly, the attachment support member 22 can be revolved without play by the elongation and contraction of the first and second cylinders 30, 32. As the first cylinder 30 is disposed along the extraction line in the longitudinal direction of a vehicle, which passes the rotational center 20, when the first cylinder points the longitudinal direction of the vehicle, it comes in the forward position of the attachment 24, and the elongation and contraction relation of the first cylinder 1 is reversed on this position as a boundary.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a cargo handling device for a lift truck, in particular,
The present invention relates to a cargo handling device that can perform cargo handling work in three directions: in front of a vehicle, and to the left and right.

Prior Art This type of cargo handling device is disclosed in Japanese Patent Application Laid-Open No. 60-236, for example.
There is a method disclosed in Japanese Patent No. 996, in which a support member to which an attachment is attached is horizontally rotatably mounted on a base member on the vehicle body side, and the support member is driven to swing via a swing drive mechanism. It is now possible to carry out cargo handling work in three directions.

The swing drive mechanism uses a hydraulic cylinder, and includes a swing arm fixed to the support member, a main link whose base end is pivotally supported on the base member, and whose free end is connected to the operating rod end of the hydraulic cylinder. an intermediate link having one end pivoted on the free end side of the main link and the other end pivoted on the free end of the swing arm;
With this structure, it is possible to perform an accurate pivoting operation without causing backlash when the supporting member is pivoted.

Problems to be Solved by the Invention However, in such a conventional lift truck cargo handling device, the swinging drive of the support member is performed by the continuous expansion and contraction operation of one hydraulic cylinder, and when the hydraulic cylinder is in the extended position, Since the support member is positioned on one side of the vehicle left or right, and the other side of the support member is positioned on the vehicle left or right at the contracted position of the hydraulic cylinder, the support member is positioned in the vehicle left or right direction. In order to position the vehicle at the front, it is necessary to stop the stroke of the hydraulic cylinder midway.

Therefore, there is a problem in that it is difficult to operate the hydraulic cylinder for positioning the support member, that is, the attachment in front of the vehicle, and requires skill.

Therefore, in view of such conventional problems, the present invention enables easy positioning of the attachment in three directions, that is, the front of the vehicle, and the left and right directions of the vehicle, and drives the support member to rotate without wobbling. The purpose of the present invention is to provide a lift truck cargo handling device that can perform the following tasks.

Means for Solving the Problems In order to achieve the above object, the present invention provides a base member that is movably mounted in the vehicle width direction at the front part of a carriage that moves up and down along the mast, and a base member that is movable in the vehicle width direction. In a cargo handling device for a lift truck, an atsotiment support member is horizontally rotatably mounted on a lift truck, and the atsotiment support member is rotated via a swing drive mechanism, wherein the swing drive mechanism is connected to a vehicle. It is placed forward and along an extension line in the longitudinal direction of the vehicle that passes through its center of rotation, and one end is rotatably supported by the attachment support member, and the other end is rotatably supported by the base member. a first cylinder supported movably, and one end rotatably supported by the attachment support member at a predetermined phase angle with a support point on one end side of the first cylinder with respect to the rotation center of the attachment support member; and a second cylinder whose other end is rotatably supported by the base member.

Further, it is preferable that the swing drive mechanism is provided with a circuit switching valve that automatically switches the supply of operating pressure in the expansion/contraction direction of the first cylinder at a position where the first cylinder is oriented in the longitudinal direction of the vehicle.

Effect With the above structure, in the lift truck cargo handling device of the present invention, the attachment support member is supported by the base member via the first cylinder and the second cylinder, and the attachment support members of the first and second cylinders are supported by the base member. Since the side support points are provided with a predetermined phase angle with respect to the rotation center of the acnotiment support member, these first and second
The attachment support member can be rotated without play by the expansion and contraction operation of the cylinder.

By the way, since the first cylinder is arranged along an extension line in the longitudinal direction of the vehicle passing through the rotation center, the attachment is in the forward position when the first cylinder is oriented in the longitudinal direction of the vehicle. The expansion and contraction relationship of the first cylinder is reversed across the directional position.

As described above, since the telescopic relationship is reversed at the position where the first cylinder is oriented in the longitudinal direction of the vehicle, it becomes easy to stop the operation of the first cylinder at the position where the telescopic relationship is reversed. In this case, the positioning operation at the front of the attachment can be easily performed.

Further, the swing drive mechanism is provided with a circuit switching valve that automatically switches the working pressure supply in the expansion/contraction direction of the first cylinder at a position where the first cylinder is oriented in the longitudinal direction of the vehicle. the vehicle left,
When turning continuously from one side to the other to the right, the first
The expansion and contraction of the cylinder is automatically switched at a position facing the longitudinal direction of the vehicle, allowing continuous turning movement without the need for special operations.

Example Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

That is, FIGS. 1 to 7 show a cargo handling device for a lift truck showing one embodiment of the present invention, and will be explained by taking an example of a forklift truck using a fork as an attachment.

In FIGS. 1 and 2, reference numeral 10 denotes a pair of masts erected in the front left and right directions of the vehicle body 12, and the masts 10 are attached via a tilt cylinder 14 so as to be swingable back and forth.

A carriage 16 is attached to the mast 10 so as to be movable up and down, and the carriage 16 is driven up and down via a lift cylinder (not shown).

Further, a base member 18 is attached to the carriage nozzle 16 so as to be movable in the left-right direction of the vehicle, and furthermore, an attachment support member 22 is attached to the front of the base member 18 in a manner that allows rotation in the horizontal direction about a support shaft 20. Possibly installed.

A fork 24 as an attachment is attached to the vehicle front of the attachment support member 22, and cargo handling work is performed via the fork 24.

Incidentally, a swing drive mechanism 26 is provided between the base member l8 and the attachment support member 22, and the fork 24 swings together with the attachment support member 22 in the X direction in FIG. 2 via the swing drive mechanism 26. By setting the fork 24 in the position shown by the solid line in the figure, cargo handling work can be performed in front of the vehicle, and cargo handling work can be performed on the right side of the vehicle by setting the fork 24 in the position shown by the dashed line. In addition, cargo handling work can be carried out on the left side of the vehicle at the position indicated by the two-dot chain line.

Note that cargo handling work in the left-right direction of the vehicle is performed by moving the base member 18 in the left-right direction of the vehicle with respect to the carriage 16.

Here, as shown in FIGS. 3 and 4, the swing drive mechanism 26 is constituted by a first cylinder 30 and a second cylinder 32, each of which is operated by hydraulic pressure, and the first cylinder 30 is the attachment support member. 22 is set at the front of the vehicle as shown in the figure, and is arranged along an extension line L in the longitudinal direction of the vehicle passing through the center of rotation, that is, the support shaft 20, and one end a on the rod 30a side is connected to the support shaft. 20 is rotatably supported via a pin 34 at a position offset to the front of the vehicle, and the other end b on the bottom 30b side,
is rotatably supported by the base member l8 via a pin 36.

On the other hand, one end a of the second cylinder 32 on the rod 32a side is connected to the attachment support member 22 via the pin 38 with a phase angle of 90° with respect to the one end a of the first cylinder 30 with respect to the support shaft 20. The other end b of the second cylinder 32 on the bottom 32b side is rotatably supported.
, is rotatably supported on the extension line L via a pin 40.

FIG. 5 shows a hydraulic circuit supplied to the first and second cylinders 30, 32, and shows the bottom side cylinder chamber 30c of the first cylinder 30 and the rod side cylinder chamber 30.
d is connected to circuits 42 and 44, and the second
Circuits 46 and 48 are connected to the bottom side cylinder chamber 32c and the rod side cylinder chamber 32d of the cylinder 32.

The circuit 42 and the circuit 48 are combined into a circuit 50, and the circuit 44 and the circuit 46 are combined into a circuit 52, each of which is operated by an oil pump 56 via a manually operated valve 54. Hydraulic pressure is supplied.

The manually operated valve 54 is manually operated in conjunction with an operating lever 58, and has a pull position 54a and a neutral position 54b.
In the pull position 54a, the oil pressure of the oil pump 56 is supplied to the circuit 50 and the circuit 52 is drained, so that the bottom side cylinder chamber 30G of the first cylinder 30 and the push position 54c are provided. Rod side cylinder chamber 32d of the second cylinder 32
Hydraulic pressure is generated.

On the other hand, in the push position 54C, hydraulic pressure is supplied to the circuit 52 and the circuit 50 is drained, so that hydraulic pressure is applied to the rod-side cylinder chamber 30d of the first cylinder 30 and the bottom-side cylinder chamber 32c of the second cylinder 32. It is supposed to occur.

Incidentally, in the neutral position 54b of the manual operation valve 54, both the circuits 50 and 52 are cut off, so that the first and second circuits 50 and 52 are cut off.
The cylinders 30, 32 are maintained in their current positions.

Incidentally, a circuit switching valve 60 is provided between the circuits 42 and 44 for automatically switching the expansion and contraction of the first cylinder 30 at a predetermined position.

The circuit switching valve 60 has a direct communication position 60a where the circuits 42 and 44 are directly connected, and a neutral position 60b.
and a cross position 60c that crosses and communicates with the circuits 42 and 44, and can be automatically switched via a cam 62 that rotates as the attachment support member 22 rotates. There is.

That is, the cam 62 is attached to the attachment support member 22.
The attachment support member 22 is mounted on the spindle 20 of the vehicle so as to be rotated together with the attachment support member 22, and as shown in FIG. Assuming that, in a position where the attachment support member 22 is directed toward the front of the vehicle, the circuit switching valve 6o can be switched from the illustrated direct position 60a to the crossed position 60c.

Note that when the attachment support member 22 is turned in the reverse direction (left turn), the circuit switching valve 60 is switched from the crossing position 60c to the direct communication position 60a when the attachment support member 22 is in a position pointing toward the front of the vehicle. It has become.

As shown in FIGS. 5 and 6, the forklift trunk cargo handling device of this embodiment is configured as described above, with the attachment support member 22 set to the left side of the vehicle as the initial position, The 26 functions are described below.

That is, when the manual operation valve 54 is pulled from the state in which the attachment support member 22 is set at the vehicle left position and switched to the position 54a, the hydraulic pressure discharged from the oil bomb 56 is transferred from the circuit 50 to the circuits 42 and 48.
is output to.

At this time, the circuit switching valve 60 is set to the direct communication position 60a by the cam 62, and the hydraulic pressure is supplied to the bottom side cylinder chamber 30c of the first cylinder 30, and the rod side cylinder chamber 30 of the second cylinder 32.
2d.

Then, the rod 30a of the first cylinder 30 is extended, and the rod 32a of the second cylinder 32 is extended.
is shortened, and the operating force at this time causes the attachment support member 22 to turn to the right about the support shaft 20.

Then, as the attachment support member 22 continues to turn to the right in this manner, in a position where the attachment support member 22 is directed toward the front of the vehicle, the rod 30a of the first cylinder 30 is rotated as shown in FIG. is fully extended, and at this time the circuit switching valve 60 is switched by the cam 62 to the cross position 60C.

Therefore, in the first cylinder 30, hydraulic pressure is supplied to the rod side cylinder chamber 30'd.
The rod 30a of the first cylinder 30 was shortened, and as a result, the attachment support member 22 continued to rotate to the right, and the rod 32a of the second cylinder 32 was shortened the most, as shown in FIG. In this state, the attachment support member 22 is set at the right position of the vehicle.

Further, when the attachment support member 22 is turned to the left from the vehicle right position, the left turn is started by pushing the manual operation valve 54 and setting it to the position 54c, contrary to the case of the left turn described above. Also, when the attachment support member 22 points toward the front of the vehicle during this left turn, the circuit switching valve 60 is in the cross position 6.
It is switched from 0C to the direct communication position 60a.

In addition, since the left and right rotations of the attachment support member 22 are performed by the expansion and contraction of the first and second cylinders 30.32 without using gears, the attachment support member 22 can be rotated to the left or right in accordance with the strokes of these cylinders 30.32. Since the attachment support member 22 is rotated in this manner, it is possible to prevent play from occurring in this rotation operation.

By the way, when the attachment support member 22 is turned left or right, the circuit switching valve 60 is switched through the neutral position 60b when the attachment support member 22 is directed toward the front of the vehicle, and the first cylinder 30 is turned to the left or right. Since the stroke direction is changed, the attachment support member 22
Although it is for a short time, it is temporarily stopped.

Therefore, by switching the manually operated valve 54 to the neutral position 54b with the aim of achieving such a stopped state, the hydraulic pressure is adjusted to the first position.
, since it is sealed in the second cylinder 30.32,
The attachment support member 22 can be easily stopped at a position in front of the vehicle.

Effects of the Invention As explained above, in the lift truss cargo handling device of the present invention, in claim 1, the rotation drive mechanism of the attachment support member is constituted by a first cylinder and a second cylinder, and these first and second cylinders are Since the support point of the cylinder on the attachment support member side is arranged at a predetermined phase angle with respect to the rotation center of the attachment support member, the attachment support member can be rotated without rattling by the expansion and contraction of these first and second cylinders. Can be driven.

Further, since the first cylinder is arranged along an extension line in the longitudinal direction of the vehicle passing through the rotation center of the attachment support member, the attachment is in the forward position when the first cylinder is oriented in the longitudinal direction of the vehicle. Since the telescopic relationship of the first cylinder is once reversed at the same position of the finger in the longitudinal direction of the vehicle, it is easy to stop the operation of the first cylinder at the position where the telescopic relationship is reversed.
In addition, positioning operations at the front of the attachment,
It is easy to perform and does not require a great deal of skill, and can significantly improve driving operability.

Furthermore, in claim 2 of the present invention, the swing drive mechanism is provided with a circuit switching valve that automatically switches the working pressure supply in the expansion/contraction direction of the first cylinder at a position where the first cylinder is oriented in the longitudinal direction of the vehicle. Therefore, when the attachment support member is continuously rotated from one side of the vehicle left or right to the other, the expansion and contraction of the first cylinder is automatically switched at a position facing the vehicle longitudinal direction, and no special operation is required. Since it is possible to perform a continuous turning movement without any movement, it has various excellent effects such as significantly improving operability.

[Brief explanation of the drawing]

FIG. 1 is an overall side view showing an embodiment of the present invention, FIG. 2 is an overall plan view showing an embodiment of the invention, and FIG. 3 is an enlarged plan view of essential parts showing an embodiment of the invention. Fig. 4 is an enlarged side view of essential parts showing one embodiment of the present invention, Fig. 5 is a schematic configuration diagram showing the entirety of the invention, and Figs. 6 and 7 show the operating state of one embodiment of the present invention. FIG. 4 is an enlarged plan view of the main parts shown respectively. DESCRIPTION OF SYMBOLS 10... Mast, 12... Vehicle body, 16... Carriage, 18... Base member, 20... Support shaft (rotation center), 22... Attachment support member, 24...
Fork (attachment), 26... Swivel drive mechanism, 30... First cylinder, 32... Second cylinder, 42, 44, 46. 48... Circuit, 54... Manually operated valve, 60 ...Circuit switching valve. Figure Figure Figure Figure Figure V

Claims (2)

[Claims] (1) A base member is mounted movably in the vehicle width direction on the front part of a carriage that moves up and down along the mast, and an attachment support member is mounted on the front part of the base member so as to be horizontally rotatable, and the attachment In a cargo handling device for a lift truck in which the support member is rotated via a rotation drive mechanism, the rotation drive mechanism is configured to rotate the attachment support member in the longitudinal direction of the vehicle passing through its center of rotation with the attachment support member set at the front of the vehicle. located along the extension of
a first cylinder whose one end is rotatably supported by the attachment support member and whose other end is rotatably supported by the base member; A second cylinder is rotatably supported by the attachment support member at a predetermined phase angle with the support point on one end side of the cylinder, and a second cylinder is rotatably supported by the base member at the other end. A lift truck cargo handling device characterized by: (2) A claim characterized in that the swing drive mechanism is provided with a circuit switching valve that automatically switches the working pressure supply in the expansion/contraction direction of the first cylinder at a position where the first cylinder is oriented in the longitudinal direction of the vehicle. Item 1. The lift truck cargo handling device according to item 1.