JPH0637292U - Forklift split type clamp device - Google Patents

Abstract

(57) [Summary] [Purpose] A split type clamp device for a forklift that can clamp cargo handling objects of different sizes beyond the play range and can use a hydraulic circuit that eliminates the need for a distribution and collection valve. provide. [Structure] The clamp device 20 includes a fixed clamp arm 2
3a and 23b, a pair of rotatably arranged movable clamp arms 22a and 22b, and a hydraulic circuit including each cylinder for rotating the movable clamp arms.
In the present invention, the torque transmission device 30 including the torsion bar 31 has one end fixed to the rotation support part of one movable clamp arm and the other end fixed to the rotation support part of the other movable clamp arm. , Are arranged coaxially with the rotation support portions 26a, 26a of the movable clamp arm. Since the pair of movable clamp arms is connected by the torsion bar, the difference in relative rotation angle between the two is absorbed by the torsion bar.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a clamp device mounted on a forklift and used for handling goods to be handled, and particularly to a split type roll suitable for handling roll-like goods to be handled such as newspaper or kraft paper take-up rolls. It is related to the clamp device.

[0002]

[Prior art]

 In general, the roll clamp device of a forklift has a poorer forward field of view than a standard attachment such as a fork, and in particular, the side gripping work of holding the take-up roll in a horizontal state has its drawbacks. Since there is a safety problem when it is desired to grip two winding rolls of different diameters at the same time, a swingable clamp arm may be used with a split type that is divided into left and right. 57-7 1198, Jitsukai Sho 58-45296 and JP-A-2-276800).

An example of the split type roll clamp device disclosed in Japanese Utility Model Laid-Open No. 58-45296 will be representatively described with reference to FIG. 5. In the clamp device, a mast of a forklift truck is compared. A support arm 2 is integrally formed at the tip of a holder 1 fixed to the front surface of a rotating device (not shown) mounted so as to be lifted up and down, and a clamp pad 3 is rotatable at the tip of the support arm 2. It is supported. A pair of clamp arms 4, 5 are rotatably supported by pins 6 near the base end of the holder 1, and a clamp pad 7 is rotatably attached to the tip of each clamp arm 4, 5. ing. A pair of clamp cylinders 8 for rotating the clamp arms 4 and 5 with respect to the support arm 2 are rotatably attached to the base end of the holder 1. A synchronizing bar 9 is projectingly provided on one side of the clamp arm 4, and a tip end of the synchronizing bar 9 is loosely attached to a cylindrical engaging portion projecting on the other side of the clamp arm 5. Has been inserted.

When the two different diameter winding rolls are arranged in a row and are clamped between the clamp pads 3 and 7 by the roll clamp device described above, both clamp arms 4 and 5 are supported by the operation of the clamp cylinder 8. It is rotated toward 2. At this time, both the clamp arms 4 and 5 rotate in a synchronized state by the synchronization bar 9 engaging with the engaging portion 10. After one clamp arm 4 clamps a large-diameter winding roll, only the other clamp arm 5 further rotates to clamp a small-diameter winding roll. However, the difference in the diameters of the different diameter winding rolls that can be simultaneously clamped by this roll clamp device is only the difference between the inner diameter of the engaging portion 10 and the outer diameter of the synchronizing bar 9 even at the maximum. It is not possible to safely clamp different diameter take-up rolls with a large difference.

Therefore, the above Japanese Utility Model Laid-Open No. 58-45296 teaches that a special hydraulic circuit is provided in the clamp device to cope with a different diameter winding roll having a large difference in diameter. That is, in FIG. 6 and FIG. 7, this hydraulic circuit connected to a hydraulic unit (not shown) on the forklift side includes a rotary valve 11 for controlling the direction of the flow of hydraulic oil supplied from the forklift side. , One port of the rotary valve 11 is connected to the rod side cylinder chamber 8a of each clamp cylinder 8 via the pipe line P ₁ , and the other port is connected to the distribution and collection valve 12 via the pipe line P _2. connected Rutotomoni, it is connected to the f head-side cylinder chamber 8b of the clamp cylinder 8 via the line P _3, P ₄ from the distribution current flow valve 12. A pilot check valve 13 is provided in each of the pipelines P ₃ and P ₄ so that the oil in the cylinder chamber 8b is discharged when the pressure in the pipeline P ₁ exceeds a predetermined value.

In the above-mentioned clamping device, when clamping different diameter winding rolls R ₁ and R ₂ having diameters d ₁ and d ₂ (d ₁ > d ₂ ) as shown in FIG. In a state where the arms 4 and 5 are open at equal intervals with respect to the support arm 2, hydraulic oil is supplied from the pipe P ₂ to the distribution and collection valve 12 via the rotary valve 11. The hydraulic oil is divided by the distribution and collection valve 12 and is supplied to each cylinder chamber 8b through one of the pipes P ₃ and the other of the pipes P ₄ so that both clamp cylinders 8 are operated and the clamp arms are clamped. 4, 5 are operated to the clamp side.

As shown in FIG. 7, if the large-diameter winding roll R ₁ is clamped by the clamp arm 4 and the small-diameter winding roll R ₂ is clamped by the clamp arm 5, respectively, the clamp arm 4 is wound. The resistances applied to both clamp cylinders 8 are equal until they come into contact with the roll R ₁ . Therefore, the hydraulic oil supplied to the distribution and collection valve 12 is equally divided and supplied to the clamp cylinder 8 via the pipes P ₃ and P ₄ , and both clamp arms 4 and 5 operate in the clamp direction in a synchronous state. To be done.

When the clamp arm 4 comes into contact with the winding roller R ₁ having a large diameter, a resistance is applied to the clamp arm 4 and the flow rate of the hydraulic oil flowing through the pipe line P ₃ is reduced. As a result, when the clamp pressure of the clamp arm 4 reaches a predetermined value, the distributor / collector valve 12 operates so as to supply hydraulic oil to the clamp cylinder 8 on the clamp arm 5 side, and the clamp arm 5 operates. It is further operated in the decelerated state to clamp the small diameter roll R ₂ .

For further details of the structure and operation of the distributor / collector valve 12, refer to the above-mentioned Japanese Utility Model Application Laid-Open No. 58-45296, ie, Japanese Patent Application No. 56-139718, if necessary. .

[0010]

[Problems to be solved by the device]

 As can be appreciated from the above description, the conventional clamping device shown in FIGS. 6 and 7 can be used even when the difference between the diameters of different diameter winding rolls that can be simultaneously clamped is maximum, as shown in FIG. There is no problem that it is not possible to simultaneously clamp different diameter take-up rolls having a large difference in diameter within the play range of the difference between the inner diameter of the joining portion 10 and the outer diameter of the synchronizing bar 9. Since the distributor / collector valve 12 is used to synchronize the movements of the two clamp arms 4 and 5, a hydraulic circuit dedicated to the split type is required instead of the hydraulic circuit for a normal roll clamp device. Not only is this disadvantageous in terms of manufacturing cost, but once there is a difference between the rotation angles of the clamp arms 4 and 5, until both pistons reach the stroke end of each cylinder 8, the clamp arms 4 and 5 on both sides are rotated. Move There is a disadvantage that must be an integer.

Accordingly, an object of the present invention is to split a forklift capable of clamping cargos of different sizes beyond the play range and using a hydraulic circuit which eliminates the need for a distributor / collector valve. Type clamp device.

[0012]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention provides a fixed clamp arm, a pair of movable clamp arms facing the fixed clamp arm and rotatably arranged with respect to the fixed clamp arm, and the movable clamp arm. In a split-type clamping device for a forklift, which is provided with a hydraulic circuit including separate cylinders for rotating the movable clamp arm, a torque transmission device is provided coaxially with a rotation support portion of the movable clamp arm. It is characterized in that one end of the movable clamp arm is fixed to the rotary support portion of the movable clamp arm and the other end is fixed to the rotary support portion of the other movable clamp arm.

[0013]

[Action]

 When pressure oil is supplied to each cylinder, the pair of movable clamp arms rotate together toward the goods to be loaded in the closing direction. If there is a difference in the diameter of the goods to be handled, one movable clamp arm that clamps the one with a larger diameter first comes into contact with the goods to be handled, so the movable clamp arm receives rotation resistance from the goods to be handled. However, the other movable clamp arm continues to rotate toward the goods to be handled. Since the pair of movable clamp arms are connected by the torque transmission device composed of the torsion bar, the difference in relative rotation angle between the two is absorbed by the torsion bar in this process. Thus, it is possible to simultaneously clamp the objects to be handled having different diameters without using the distribution / collection valve.

If the hydraulic circuit is operated to open the movable clamp arm in order to release the clamped object to be handled, the torque of the difference in the rotational angle absorbed by the torsion bar is large in the movable clamp. Transmitted to the arm, both movable clamp arms are aligned at the same angular position.

[0015]

【Example】

 Next, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, in which the same reference numerals indicate the same or corresponding parts.

FIG. 1 schematically shows a preferred embodiment of the split roll clamp device 20 according to the present invention in a substantially horizontal state. A pair of short clamp arms 23a and 23b (fixed clamp arms) having a common pad 25 at one end (left end in the drawing) of the frame 21 of the clamp device 20 is rotatable by means of a pin. The base ends of the pair of long clamp arms 22a and 22b (movable clamp arms) which are coupled to the other end by means of pins or shafts 26a and 26b (rotary support parts) coaxially aligned. The parts are rotatably connected. Pads 24a and 24b are preferably rotatably attached to the tip ends of the clamp arms 22a and 22b, respectively.

Although not shown in FIG. 1, a hydraulic cylinder is mounted on the back side of the frame 21 for each clamp arm. The tip end of the piston rod extending from the hydraulic cylinder is connected to the pins 27a and 27b on the back side of the corresponding clamp arm. By operating the hydraulic cylinder, the long clamp arms 22a and 22b are connected to the frame 21. Alternatively, the short clamp arms 23a and 23b are rotated.

According to the present invention, the above-described clamp device 20 is arranged between the proximal ends of the long clamp arms 22a and 22b and fixed to the shafts 26a and 26b at both ends thereof. Equipped with 30.

In the preferred embodiment, as shown in detail in FIG. 2, each shaft 26a, 26b has an inwardly projecting extension into which the torsion bar 31 of the torque transmitting device 30 is extended. Each grip or end is fitted and secured thereto, preferably by such means as welding. The effective length, radius arm, bar diameter, etc. of the torsion bar 31 are such that one of the long clamp arms 22a and 22b is fully opened and the other is fully closed, even if the relative rotation angle is the largest, the torsion bar is damaged. In order to have sufficient strength, and in cooperation with the action of sliding resistance of the shafts 26a, 26b, etc., which are the rotation support parts, the variation of the operating speed between the clamp arms 22a, 22b and thus the fluctuation of the rotation angle is suppressed. Is designed to be. In FIG. 2, rod-shaped pins 28a and 28b attached to bolts 29a and 29b at the base ends of the clamp arms 26a and 26b are used to rotate the corresponding clamp arms in cooperation with the extension of the shaft. It is a stopper that limits

FIG. 3 shows a hydraulic circuit 40 used to operate the above-described clamp device 20. Since this hydraulic circuit 40 may be a normal roll clamp type (see Japanese Patent Application Laid-Open No. 2-276800) that is not a split type, it goes without saying that the distribution assembly described with reference to FIGS. 6 and 7 is used. No flow valve is required. However, like the hydraulic circuit of FIGS. 6 and 7, the hydraulic circuit of the clamp device 20 of the present invention also includes the rotary valve 11 that controls the direction of the flow of the hydraulic oil supplied from the forklift side. , One port of the rotary valve 11 is connected to the rod side cylinder chamber 8a of each clamp cylinder 8 (which is provided on the back side of the frame 21 as described above) via the pipe P ₁ , and the other port Is connected to the head side cylinder chamber 8b of the clamp cylinder 8 via a pipe line P ₂ . A pilot check valve 13 is provided in the pipe line P ₂ so that the oil in the cylinder chamber 8b is discharged when the pressure in the pipe line P ₁ exceeds a predetermined value.

Therefore, when pressure oil is supplied to each cylinder chamber 8b by operating the rotary valve 11, the long clamp arms 22a and 22b both rotate in the closing direction toward the winding rolls R ₁ and R ₂ having different diameters. To do. As shown in FIG. 3, when the diameters d ₁ and d ₂ of the take-up roll are different, the clamp arm 22a _first comes into contact with the take-up roll R ₁ , so that the clamp arm 22a is rotated from the take-up roll R _1. Although it receives dynamic resistance, the other clamp arm 22b continues to rotate toward the winding roll R ₂ . Since the clamp arms 22a and 22b are connected by the torsion bar 31, the torsion bar 31 absorbs the difference in relative rotational angle between the two in this process. Thus, the different-diameter winding rolls R ₁ and R ₂ can be simultaneously gripped by the clamp device 20 shown in FIG.

Further, in order to release the grasped different diameter winding rolls R ₁ and R ₂ , the rotary valve 11 is operated to open the clamp arms 22a and 22b. The torque of the difference in angle is transmitted to the clamp arm having a large rotation angle (22b in the embodiment), and both clamp arms are aligned at the same angular position.

FIG. 4 shows a modified embodiment of the present invention, in which the shafts 26a 'and 26b' (rotation supporting portions) are formed in a hollow shape, and both of the hollow portions are provided with a torsion bar 31 '(torque). A transmission device) extends through and is secured to the outer end of the shaft by any suitable means such as welding. In the embodiment of FIGS. 1 and 2, it was necessary to incorporate the torsion bar during the assembly of the clamp device to manufacture the same, but according to this modified embodiment, the torsion bar is inserted into the shaft after assembly. Therefore, it is relatively easy to manufacture. Needless to say, the clamp function of this modified embodiment is equivalent to that of the above-mentioned clamp device.

The preferred embodiment of the present invention has been described above with respect to the split type roll clamp device for handling the take-up roll, but the present invention is not limited to this and various modifications can be made.

For example, although the torsion bar is used in the above-described embodiment, if the rotation torque of one clamp arm can be transmitted as the rotation force of the other clamp arm, a torsion coil spring, for example, can be used. Appropriate members can be adopted. In addition, although the torsion bar was fixed to the shaft in all the examples, if the torsion bar is coaxially aligned with the shaft, each end of the torsion bar should be connected to the proximal side (rotation) of the corresponding clamp arm. It may be fixed to the dynamic support portion). Further, if the torsion bar is formed integrally with the two shafts and the torsion bar itself is used as the rotation supporting portion of the clamp arm, the number of parts can be minimized.

[0026]

[Effect of device]

 According to the present invention, since the pair of clamp arms are connected to each other by the rotation support portion by the torque transmission device, a hydraulic circuit for a normal roll clamp device, which is not a split type, can be used, and therefore, the distribution collecting valve. Since this is not incorporated in the hydraulic circuit, the degree of freedom in designing the forklift can be increased and the manufacturing cost can be reduced. Furthermore, even after the clamp device has clamped goods to be handled with different diameters, if both clamp arms are opened to release them, the action of the torque transmission device ensures that both clamp arms are substantially aligned at the same angular position. The troublesome work of moving to the stroke end is unnecessary, and both clamp arms are essentially aligned at the same angular position at the start of clamping. It is possible to prevent accidents where the tip of the clamp arm is damaged.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a split type roll clamp device according to the present invention.

FIG. 2 is a partially enlarged side view showing a main part of the clamp device of FIG.

FIG. 3 is a schematic system diagram of a hydraulic circuit used in the clamp device of FIG.

FIG. 4 is a side view showing a modified embodiment of the present invention.

FIG. 5 is a perspective view of a conventional split type roll clamp device.

FIG. 6 is a perspective view showing another conventional split type roll clamp device.

7 is a schematic system diagram showing a hydraulic circuit used in the clamp device of FIG.

[Explanation of symbols]

8 ... Shaft, 20 ... Split type clamp device, 22
a, 22b ... Movable clamp arm, 23a, 23b ... Fixed clamp arm, 26a, 26b ... Shaft (rotation support part), 26a ', 26b' ... Shaft (rotation support part), 30 ... Torque transmission device, 31, 31 '... torsion bar, 40 ... hydraulic circuit.

Claims (1)

[Scope of utility model registration request] 1. A fixed clamp arm, a pair of movable clamp arms facing the fixed clamp arm and rotatably disposed with respect to the fixed clamp arm, and the movable clamp arm coupled to the movable clamp arm. In a split-type clamp device for a forklift including a hydraulic circuit including respective cylinders to be rotated, a torque transmission device is provided coaxially with a rotation support portion of the movable clamp arm, and one end of the torque transmission device rotates the movable clamp arm. A split type clamp device for a forklift, wherein the split type clamp device is arranged so that it is fixed to a dynamic support part and the other end is fixed to a rotation support part of the other movable clamp arm.