JPS6234959Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a roll clamp device that is attached to a forklift truck and used for handling and transporting cylindrical objects such as rolled paper. A roll clamp device in which one side is attached to a rotatable clamp arm, and the clamp arm is rotated toward the other clamp pad by an actuating device such as a hydraulic cylinder, thereby clamping the conveyed object between both clamp pads. It is about improvement.

Conventionally, as this type of roll clamp device, an orthodox device in which a rotatable clamp arm is integrally formed without being divided has been mainly used. However, since the roll clamp device described above cannot grip two rolls of different diameters at the same time, a device with a split clamp arm has also been used to make this possible.

As shown in Fig. 1, a conventional split roll clamp device has a support arm at the tip of a holder 1 fixed to the front of a rotating device (not shown) that can be raised and lowered from the mast of a forklift truck. A clamp pad 3 is rotatably supported at the tip of the support arm 2. A pair of clamp arms 4 and 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 and 5. . A pair of clamp cylinders 8 for rotating the clamp arms 4 and 5 toward the support arm 2 are rotatably attached to the base end of the holder 1. A synchronization bar 9 is protruded from the side of the one clamp arm 4, and the other clamp arm 5 is attached to the tip of the synchronization bar 9.
It is loosely inserted into a cylindrical engaging portion 10 that protrudes from the side.

When this roll clamp device grips two rolls of different diameters at the same time, both clamp arms 4 and 5 are rotated toward the support arm 2 by the operation of the clamp cylinder 8. The synchronization bar 9 is the engagement part 10
By engaging with the clamp arms 4 and 5, both clamp arms 4 and 5 rotate in synchronization. After one clamp arm 4 clamps the large diameter roll, only the other clamp arm 5 rotates further to clamp the small diameter roll. However, the difference in diameter between rolls of different diameters that can be simultaneously clamped by this roll clamping device is only the difference between the inner diameter of the engaging portion 10 and the outer diameter of the synchronization bar 9 at most, and the difference in diameter is large. It was not possible to clamp rolls of different diameters at the same time.

This invention was made in order to eliminate the above-mentioned conventional defects, and its purpose is that even when two rolls with large diameter differences are grabbed at the same time, abnormal clamping pressure is applied to each roll. It is an object of the present invention to provide a roll clamping device that does not cause such problems and can also grip a single roll using only one clamp arm.

Examples 2 to 6 that embody this idea are as follows.
This will be explained according to the diagram. The roll clamp device of this invention differs from conventional devices in that it does not include a mechanical synchronizer, but instead provides a distribution and collector valve with a synchronizing action in the hydraulic circuit for operating the clamp cylinder 8. The basic configuration is the same as the device shown in FIG. 1, and the same parts are designated by the same reference numerals. Unlike the conventional device, there is no mechanical synchronization device, so there is a gap between the pair of clamp arms 4 and 5, which are configured to be able to operate independently by the clamp cylinder 8, as shown in FIGS. 2 and 3. A space S is formed in the space S.

The holder 1 is provided with a rotary valve 11 that is connected to a hydraulic unit (not shown) on the forklift truck side and controls the direction of flow of hydraulic oil supplied from the forklift truck side. One port of the rotary valve 11 is connected to the rod-side cylinder chamber 8a of each clamp cylinder 8 via a pipe _P1 , and the other port is connected to a pipe P1.
It is connected to the distribution collector valve 12 via _P2 . The distribution/collection valve 12 is connected to the head-side cylinder chamber 8b of the clamp cylinder 8 via pipes P ₃ and P ₄ . A pilot check valve 13 is provided in each of the pipes P ₃ and P ₄ , and when the pressure in the pipe P ₁ exceeds a predetermined pressure, the flow check valve is released.
The oil in the cylinder chamber 8b of each clamp cylinder 8 is drained.

As shown in FIG. 5, the distribution/collection valve 12 has a port A connected to the pipe _P2 , a port B connected to the pipe _P3 , and a port connected to the pipe _P4 . It has a pair of spools 16 and 17 in which a small diameter fixed orifice 14 and a large diameter variable orifice 15 are formed. Hook portions 16a and 17a that can be engaged with each other are formed at one end of each spool 16 and 17, and both the hook portions 16a and 17a are engaged with each other by a spring 18 interposed between the spools 16 and 17. is energized by Further, both spools 16 and 17 are connected to springs 1 disposed at both ends of the distribution/collection valve 12.
9 and 20, when the amounts of oil flowing through both ports B and C are equal, the distribution and flow collecting valve 12 is held at the center position.

In addition, the spools 16 and 17 move on both sides of the variable orifice 15 of each of the spools 16 and 17, so that when the communication between each port B and C and the variable orifice 15 is cut off, each port B and C Bypass holes 21 and 22 that can communicate with each other are provided.

Next, the operation of the clamp device configured as described above will be explained. When clamping rolls R ₁ and R ₂ of different diameters with diameters d ₁ and d ₂ (d ₁ > d ₂ ), both clamp arms 4 and 5 are placed against the support arm 2 as shown in FIG. Hydraulic oil from a hydraulic source is supplied to port A of the distribution/collection valve 12 via the rotary valve 11, which is opened at equal intervals. The hydraulic oil is divided by the distribution flow collecting valve 12, and one side is supplied from port B through pipe _P3 , and the other is supplied from port C through pipe _P4 to the head side cylinder chamber 8b of the clamp cylinder 8, respectively. As a result, both clamp cylinders 8 are operated, and the clamp arms 4 and 5 are operated toward the clamp side.

As shown in Fig. 4, if the large diameter roll R ₁ is clamped by the clamp arm 4 and the small diameter roll R ₂ is clamped by the clamp arm 5, both the rolls are clamped until the clamp arm 4 comes into contact with the roll R ₁ . The resistances applied to the clamp cylinder 8 are equal. Therefore, the resistance applied to both ports B and C of the distribution/collection valve 12 is equal, and each spool 16, 17 is held at the neutral position shown in FIG. 5, so the hydraulic oil supplied from port A is divided equally. It is distributed and supplied to the clamp cylinder 8 from ports B and C, and both clamp arms 4 and 5 are actuated in the clamping direction in a synchronous state.

When the clamp arm 4 comes into contact with the large-diameter roll _R1 , resistance is added to the clamp arm 4, and the flow rate of the hydraulic oil flowing through the pipe _P3 is reduced. Then, due to the action of the orifice 14, the pressure difference between the chamber L and the chamber N on the spool 17 side increases, that is, the pressure in the chamber N decreases compared to the pressure in the chamber L,
The spool 17 moves to the chamber N side (rightward in FIG. 5) against the elastic force of the spring 20, and the spool 16 is also pulled by the spool 17 via the hooks 16a and 17a and moves to the right. Moving. When the clamp pressure of the clamp arm 4 reaches a predetermined pressure, port B is closed by the spool 16 as shown in FIG. 6, but port C is closed by the bypass hole provided near the variable orifice 15 of the spool 17. 22
The clamp cylinder 8 on the clamp arm 5 side is maintained in a state where hydraulic oil is supplied to the clamp cylinder 8 on the clamp arm 5 side through the bypass hole 22. Therefore, clamp arm 4
After clamping the large-diameter roll R ₁ at a predetermined clamping pressure, the distribution/collection valve 12 closes the spool 17
Since the hydraulic oil flows only from the bypass hole 22 to the port C side, the clamp arm 5 is further operated in a decelerated state to clamp the small diameter roll _R2 . After both rolls R ₁ and R ₂ are clamped, the pressures in the chambers L, M, and N become equal, and the spools 16 and 17 return to their neutral positions. After the large diameter roll R ₁ is clamped as described above, the large diameter roll R ₁ is clamped until the small diameter roll R ₂ is clamped.

When both clamp arms 4 and 5 are opened from the clamped state, hydraulic oil from the hydraulic source flows to the pipe _P1 side via the rotary valve 11,
Hydraulic oil is supplied to the rod-side cylinder chambers 8a of both clamp cylinders 8 through the pipe _P1 . When the pressure in the pipe P ₁ exceeds a predetermined pressure, the flow check by the pilot check valve 13 is released, and the oil in the cylinder chamber 8b of each clamp cylinder 8 flows into the pipe P ₃ ,
It is discharged through P ₄ . Both clamp arms 4 and ₅ are operated at the same speed until the oil in the cylinder chamber 8b of the clamp cylinder 8 on the side of the clamp arm 4 that clamps the large-diameter roll R ₁ is discharged. , R ₂ are simultaneously released from the clamped state. Cylinder chamber 8 on the clamp arm 4 side
After the oil b is discharged, only the oil in the cylinder chamber 8b on the clamp arm 5 side is further discharged. At this time, oil flows into the distribution/collection valve 12 only from the port C side, so the pressure in the chamber N increases and the spool 17
moves to the left in FIG. 5 against the elastic force of the spring 18. However, since the spool 17 is provided with a bypass hole 21, even after the spool 17 moves to the left, the oil flowing from port C is discharged from port A through the bypass hole 21.
Both clamp arms 4, 5 then return to the initial state shown in FIG. In addition, when clamping rolls of different diameters continuously, if the arrangement of the large diameter roll R ₁ and the small diameter roll R ₂ is constant, it is not necessary to return the opening degrees of both clamp arms 4 and 5 to the same state. .

For example, when one roll is grabbed by the clamp arm 4, the clamp arm 5, which is free after the clamp arm 4 has clamped the roll, operates until the end of the stroke of the clamp cylinder 8 when left alone. However, the operator visually determines whether the single grip is stable (if the free clamp arm 5 precedes the clamp arm 4), or by checking the relief sound before the free clamp arm 5 moves to the end of its stroke. By operating the rotary valve 11 at the same time, it is possible to quickly pick up one piece.

As described in detail above, this invention provides a holder with a support arm integrally formed at the tip thereof, and a pair of clamp arms rotatably provided therein, and a mechanism for rotating each of the clamp arms toward the support arm. A pair of clamp cylinders are provided, and the two clamp cylinders are connected via a pipe line through a distribution collector valve, and the distribution collector valve has resistance on one side of the clamp cylinder, and the spool of the distribution collector valve has both outlets. By providing a bypass hole to allow oil to be supplied to the other clamp cylinder even when the side port is moved in the direction of closing it, it is possible to grasp two rolls with large diameter differences at the same time. Even when the rolls are closed, no abnormal clamping pressure is applied to the individual rolls, and there is no risk of damage to the rolls. In addition, it is possible to grip a single roll using only one clamp arm, and since there is no mechanical synchronization device, there is a hollow space between both clamp arms, so the visibility when horizontally gripping the roll is reduced. It has excellent effects such as improving health.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a conventional device, Fig. 2 is a partial perspective view of a device embodying this invention seen from the back, Fig. 3 is a partially schematic perspective view, and Fig. 4 is a hydraulic circuit diagram. , Fig. 5 is a vertical cross-sectional view of the distribution/collection valve, Fig. 6
The figure is a longitudinal cross-sectional view showing the operating state of the distribution flow collecting valve. 1... Holder, 2... Support arm, 4, 5...
...Clamp arm, 8...Clamp cylinder, 1
2... Distribution collector valve, 16, 17... Spool, 2
1, 22... Bypass hole.

Claims (1)

[Claims for Utility Model Registration] A pair of clamp arms are rotatably provided on a holder integrally formed with a support arm at the tip thereof, and a mechanism for rotating each of the clamp arms toward the support arm is provided. A pair of clamp cylinders are provided, the two clamp cylinders are connected by a pipe line through a distribution collector valve, and resistance is applied to one of the clamp cylinders in the distribution collector valve, and the spool of the distribution collector valve has both outlets. A roll clamp device characterized in that a bypass hole is provided to enable oil to be supplied to the other clamp cylinder even when the side port is moved in the direction of closing the side port.