Overload protection device for toggle rod press

Abstract

The invention relates to an overload protection device for a toggle rod press. The overload protection device comprises a cylinder body, a piston, a locking ring, a cushion block, an inclined block, a screw rod, a pin shaft, an inclined block mounting seat and a sliding block; the piston is arranged in the cylinder body and can move up and down along an inner cavity of the cylinder body; the locking ring is arranged in the cylinder body and used for limiting the limiting position of downward movement of the piston. The cushion block is arranged below the piston and can only move up and down; the inclined block is arranged below the cushion block, and the inclined surface of the inclined block is in contact with the cushion block; the inclined block is connected with the pin shaft in a matched mode through a hole shaft, and the pin shaft moves left and right and drives the inclined block to move left and right. The pin shaft is provided with an internal thread hole which is matched with the external thread of the screw rod; the inclined block is arranged on the inclined block mounting seat, and the inclined block mounting seat is connected with the sliding block. Hydraulic pre-tightening is combined with the inclined plane mechanism, the inclined plane mechanism and the cushion block form a rigid force transmission chain, the oil cylinder provides constant supporting force, and during overload, the oil cylinder firstly acts and releases pressure, so that a transmission path of abnormal force is cut off, and key protection on a core structure of the press is realized.

Description

Technical Field

[0001] This invention relates to the field of elbow press technology, and more particularly to an overload protection device for an elbow press. Background Technology

[0002] Currently, overload protection devices for toggle presses primarily employ hydraulic principles, achieving overload relief through preset pressure. However, existing technology has significant limitations, generally integrating the device within the press slide. This structural layout is only suitable for models where the sealing height adjustment mechanism is located inside or below the slide. For toggle presses where the sealing height adjustment mechanism is located above the press, the existing built-in device cannot be installed due to the space occupied by the adjustment mechanism, resulting in a long-standing lack of effective structural overload protection for this type of machine. Summary of the Invention

[0003] The purpose of this invention is to provide an overload protection device for an elbow press to solve the problems in the prior art.

[0004] The technical solution of the present invention is: an overload protection device for an elbow press, the overload protection device comprising a cylinder, a piston, a locking ring, a pad, a wedge block, a screw, a pin, a wedge block mounting base, and a slider; The piston is disposed inside the cylinder and can move up and down along the inner cavity of the cylinder; The locking ring is installed inside the cylinder to limit the piston's downward movement to extreme positions; The pad is positioned below the piston, and the pad can only move up and down; The inclined block is positioned below the pad block, and its inclined surface contacts the pad block; The inclined block and the pin are connected by a hole shaft, and the pin moves left and right, which in turn drives the inclined block to move left and right. The pin is provided with an internal threaded hole, which is compatible with the external thread of the screw. The inclined block is mounted on an inclined block mounting base, which is connected to the slider.

[0005] Furthermore, the locking ring is fixedly installed inside the cylinder to fix the initial position of the piston.

[0006] Furthermore, the contact surface between the inclined block and the pad is an inclined surface, which is used to convert the vertical force transmitted by the slider into a horizontal force.

[0007] Furthermore, the pin and the screw are connected by a thread, and the rotation of the screw drives the pin to move left and right.

[0008] The beneficial effects of this invention are: combining hydraulic preload with the inclined plane mechanism: during normal operation, the inclined plane mechanism and the pad block form a rigid force transmission chain, and the oil cylinder provides a constant supporting force; during overload, the oil cylinder acts first and releases pressure, thereby cutting off the transmission path of abnormal force and achieving critical protection for the core structure of the press. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the structure of the present invention.

[0010] In the diagram, 1 is the cylinder, 2 is the piston, 3 is the locking ring, 4 is the pad, 5 is the wedge block, 6 is the screw, 7 is the pin, 8 is the wedge block mounting base, and 9 is the slider. Detailed Implementation

[0011] An overload protection device for an elbow press, the overload protection device comprising a cylinder 1, a piston 2, a locking ring 3, a pad 4, a wedge block 5, a screw 6, a pin 7, a wedge block mounting base 8, and a slider 9; The piston 2 is disposed inside the cylinder 1 and can move up and down along the inner cavity of the cylinder 1; The locking ring 3 is installed inside the cylinder 1 to limit the downward movement of the piston 2 to the extreme position. The pad 4 is located below the piston 2, and the pad 4 can only move up and down; The inclined block 5 is positioned below the pad block 4, and its inclined surface is in contact with the pad block 4; The inclined block 5 and the pin 7 are connected by a hole shaft fit, and the pin 7 moves left and right, which drives the inclined block 5 to move left and right. The pin 7 is provided with an internal threaded hole, which is adapted to the external thread of the screw 6; The inclined block 5 is mounted on the inclined block mounting base 8, and the inclined block mounting base 8 is connected to the slider 9.

[0012] The locking ring 3 is fixedly installed inside the cylinder 1 to fix the initial position of the piston 2.

[0013] The contact surface between the inclined block 5 and the pad block 4 is an inclined surface, which is used to convert the vertical force transmitted by the slider 9 into a horizontal force.

[0014] The pin 7 and the screw 6 are connected by a thread, and when the screw 6 rotates, it drives the pin 8 to move left and right.

[0015] The working process of this invention is as follows: Initial state: High-pressure oil fills cylinder 1, pushing piston 2 downward until piston 2 is blocked by locking ring 3 fixed inside cylinder 1. At this time, the oil pressure applies a downward force to piston 2, which is transmitted through piston 2 → pad 4 → wedge 5 → wedge mounting seat 8 → slider 9, providing the machine tool with a stable, pre-set nominal pressure. At this time, slider 9 is in the ready-to-work position.

[0016] Operating state: The machine tool is started, and the slide block 9 moves downward to press the workpiece. The workpiece generates an upward reaction force on the slide block 9, which is transmitted through the slide block 9 → inclined block mounting seat 8 → inclined block 5. Since the inclined block 5 has an inclined surface, the upward force is decomposed on the inclined surface into a positive pressure perpendicular to the inclined surface and a horizontal component force. The positive pressure is transmitted through the inclined block 5 to the pad 4, and then to the piston 2. The horizontal component force attempts to push the inclined block 5 to move left and right, but since the pad 4 is restricted to left and right movement, this horizontal force is completely canceled out by the reaction force of the pad 4.

[0017] Within the normal operating range, the workpiece reaction force is less than or equal to the preset downward force of the hydraulic cylinder. Therefore, the resultant force transmitted to piston 2 (mainly positive pressure) cannot overcome the hydraulic pressure, piston 2 remains stationary, the hydraulic cylinder pressure is stable, and the machine tool continues to press normally.

[0018] When it is necessary to adjust the mold height (sealing height), rotating the screw 6 causes the threaded pin 7 to move left and right. The pin 7 causes the wedge block 5, which mates with the shaft, to move left and right, thereby changing the height of the entire force support point and achieving fine adjustment of the sealing height. During this process, the pad block 4 also plays a role in counteracting the lateral force generated by the left and right movement of the wedge block 5, protecting the piston 2 from jamming.

[0019] Overload protection state: When the workpiece is abnormal (such as excessive material thickness, double material feeding) or the mold is not properly adjusted, the upward reaction force on the slider 9 exceeds the preset downward force of the hydraulic cylinder. The excessive force is transmitted to the piston 2 through the above path. The resultant upward force acting on the piston 2 is greater than the oil pressure, and the piston 2 is pushed upward, resulting in a slight upward displacement. The upward movement of the piston 2 causes the closed volume of the hydraulic cylinder 1 to change instantaneously, triggering the rapid pressure relief valve inside the hydraulic system.

[0020] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An overload protection device for a knuckle joint press, characterized by: The overload protection device includes a cylinder (1), a piston (2), a locking ring (3), a pad (4), a wedge (5), a screw (6), a pin (7), a wedge mounting base (8), and a slider (9); The piston (9) is disposed inside the cylinder (1) and can move up and down along the inner cavity of the cylinder (1); The locking ring (3) is installed inside the cylinder (1) to limit the downward movement of the piston (2) to the extreme position; The pad (4) is located below the piston (2), and the pad (4) can only move up and down; The inclined block (5) is located below the pad block (4), and its inclined surface is in contact with the pad block (4); The inclined block (5) and the pin (7) are connected by a hole shaft. The pin (7) moves left and right and drives the inclined block (5) to move left and right. The pin (7) is provided with an internal threaded hole, which is adapted to the external thread of the screw (6); The inclined block (5) is mounted on the inclined block mounting base (8), and the inclined block mounting base (8) is connected to the slider (9).

2. An overload protection device for a knuckle-lever press according to claim 1, characterized in that: The locking ring (3) is fixedly installed inside the cylinder (1) to fix the initial position of the piston (2).

3. An overload protection device for an elbow press according to claim 1, characterized in that: The contact surface between the inclined block (5) and the pad block (4) is an inclined surface, which is used to convert the vertical force transmitted by the slider (9) into a horizontal force.

4. An overload protection device for a lever press according to claim 1, characterized in that: The pin (7) and the screw (6) are connected by a thread. When the screw (6) rotates, it drives the pin (7) to move left and right.

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