An automatic reset compression mechanism

Abstract

The utility model discloses an automatic reset compression mechanism belongs to the technical field of compression mechanism, including base and setting on the base compression arm, guide component, reset spring, the left end of compression arm is hinged on the hinge seat through the hinge pin, the right end of compression arm is set as the compression head section and operating section in the direction of away from the hinge pin in proper order, reset spring is set as the torsional spring, the torsional spring cover is established on the hinge pin, the guide component includes the guide groove of setting on the base and the guide block being connected with compression arm, the guide groove is set as the arc slot with the axle of hinge pin as the center, the utility model discloses adopt the arc guide groove of coaxial with hinge pin's axle center, make the sliding track of guide block and the rotation track of compression arm perfect coincidence, formed a radial limit system, effectively resist any direction's lateral force, completely put an end to the radial of compression arm's shift, and the defect of traditional scheme is solved.

Description

Technical Field

[0001] This utility model relates to the field of clamping mechanism technology, and in particular to an automatic reset clamping mechanism. Background Technology

[0002] In industrial production, clamping mechanisms are widely used in fixtures, assembly lines, and other scenarios for quickly clamping or fixing workpieces. A fast and reliable clamping mechanism is key to improving production efficiency. In existing technologies, lever-type clamping mechanisms often use springs for reset, but this has significant drawbacks: First, commonly used tension or compression springs are prone to fatigue and relaxation after long-term use, leading to weak reset or failure. Furthermore, their installation requires additional space, resulting in a less compact structure. Second, and more critically, traditional lever-type clamping rods lack effective radial constraint during clamping and reset. When subjected to lateral or eccentric forces, they are prone to radial movement around the hinge point, or even jamming. This not only reduces the accuracy of the clamping position and affects processing quality but also accelerates wear on the hinge area, shortening equipment lifespan.

[0003] Although some designs attempt to incorporate guide structures, most are simple linear guides that do not match the circular motion trajectory of the pressure rod, easily causing motion interference and additional friction, resulting in poor performance.

[0004] Therefore, there is an urgent need for a clamping mechanism that can simultaneously solve the problems of automatic reset reliability and motion trajectory accuracy. Utility Model Content

[0005] The purpose of this invention is to provide an automatic reset clamping mechanism to solve the problems in the background art.

[0006] To achieve the above objectives, this utility model provides an automatic reset clamping mechanism, including a base and a pressure arm, a guide assembly, and a reset spring disposed on the base. A hinge seat is fixedly disposed on the base. The left end of the pressure arm is hinged to the hinge seat via a hinge shaft. The right end of the pressure arm is sequentially configured as a pressure head section and an operating section along the direction away from the hinge shaft. The lower end of the pressure head section is provided with a pressure head for clamping the workpiece. The reset spring is a torsion spring, which is sleeved on the hinge shaft. The two ends of the torsion spring are respectively fixed to the base and the pressure arm. The guide assembly includes a guide groove formed on the base and a guide block connected to the pressure arm. The guide block is slidably embedded in the guide groove, and the guide groove is configured as an arc-shaped groove with the axis of the hinge shaft as the center.

[0007] Preferably, the torsion spring is a preload torsion spring, which provides a preload torque to keep the pressure arm in the initial reset position when the pressure arm is in that position.

[0008] Preferably, the hinge shaft is configured as a stepped shaft structure, comprising, in sequence along the axial direction: a first shoulder, a first shaft segment, a second shoulder, a second shaft segment, a third shoulder, a third shaft segment, a fourth shaft segment, and a shaft end hole; wherein, the first shoulder is used to abut against the hinge seat on one side of the base to achieve axial positioning; the first shaft segment is interference-fitted with the hinge seat hole on one side of the base; the second shoulder is located between the first shaft segment and the pressure arm, used to separate the hinge seat and the pressure arm; the second shaft segment is clearance-fitted with the hinge hole of the pressure arm; the third shoulder is located between the pressure arm and the torsion spring, used to separate the pressure arm and the torsion spring; the diameter of the third shaft segment is smaller than that of the second shaft segment, allowing the torsion spring to be fitted with it and a gap exists between them; the fourth shaft segment is interference-fitted with the hinge seat hole on the other side of the base; the shaft end hole is opened at the end of the fourth shaft segment, used to install an elastic retaining ring to achieve axial fixation of the hinge shaft.

[0009] Preferably, the guide block is adapted to the guide groove, and the guide block and the pressure arm are detachably connected by a connecting rod.

[0010] Preferably, the pressure head is detachably connected to the lower end of the pressure head section of the pressure arm. Preferably, a spherical washer is provided between the pressure head and the pressure arm.

[0011] Preferably, both the base and the pressure arm have slots for fixing the torsion spring.

[0012] Preferably, the operating section of the pressure arm is provided with a handle fixed to the pressure arm, and the surface of the handle is provided with anti-slip texture.

[0013] Preferably, the operating section of the pressure arm is provided with a connecting block, and the pressure arm is connected to the drive assembly through the connecting block. Therefore, the automatic reset pressing mechanism of the present invention, with the above structure, has the following beneficial effects: (1) This utility model uses a torsion spring as a reset spring and directly sleeves it on the hinge shaft of the pressure arm. The two ends of the torsion spring are directly fixed to the slots on the pressure arm through the base. This design minimizes the reset force transmission path and avoids the force transmission loss caused by the installation structure of the tension / compression spring. At the same time, the torsion spring and the hinge shaft are coaxially integrated, requiring no additional installation space and overcoming the disadvantages of tension / compression springs being prone to fatigue and taking up space.

[0014] (2) The core of this utility model is to set the guide groove of the guide component as an arc groove with the hinge shaft as the center, and the guide block is precisely matched with the guide groove and slidably embedded. This design ensures that when the pressure arm rotates, the guide block always slides along an arc trajectory concentric with the hinge shaft, forming a rigid constraint mechanism for the rotation trajectory. This ensures that the rotation trajectory of the pressure arm is precisely constrained on the predetermined arc line, which can effectively offset the radial force generated by factors such as off-center load and unbalanced operation, completely eliminate the risk of radial movement and jamming of the pressure arm, and greatly improve the repeatability accuracy of the pressing position and the rigidity and service life of the entire mechanism.

[0015] (3) In this utility model, the guide block and the pressure arm are detachably connected by a connecting rod. When the guide block is worn due to long-term sliding, it can be disassembled and replaced separately without replacing the entire pressure arm or base, thus reducing maintenance costs. The pressure head and the pressure arm are detachably connected, and different types of pressure heads such as flat, spherical, and irregular shapes can be quickly replaced according to the size and shape of the workpiece. A single mechanism can adapt to various workpiece processing needs, improving the versatility of the equipment.

[0016] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model; Figure 2 This is a cross-sectional view of the hinge seat in an embodiment of the present utility model; Figure label: 1. Base; 2. Pressure arm; 3. Hinge seat; 4. Torsion spring; 5. Hinge shaft; 6. Pressure head; 7. Arc-shaped guide groove; 8. Guide block. Detailed Implementation

[0018] The technical solution of this utility model will be further described below with reference to the accompanying drawings and embodiments.

[0019] Unless otherwise defined, the technical or scientific terms used in this utility model shall have the ordinary meaning understood by one of ordinary skill in the art to which this utility model pertains. The terms "first," "second," and similar terms used in this utility model do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0020] Example like Figures 1-2 As shown, this utility model provides an automatic reset pressing mechanism, including a base 1 and a pressing arm 2, a guide assembly, and a reset spring disposed on the base 1. The left end of the pressing arm 2 is hinged to the hinge seat 3 on the left side of the base 1 via a hinge shaft 5. The right end consists of a pressing head 6 segment and an operating segment (the pressing head 6 segment is close to the hinge shaft 5, and the operating segment is at the rightmost end) in a direction away from the hinge shaft 5, forming a lever structure with "fixed hinge on the left end and segmented function on the right end". The torsion spring 4 is sleeved on the hinge shaft 5 to achieve reset, and the guide assembly constrains the rotation trajectory of the pressing arm 2. The overall structure is compact and the motion logic is clear.

[0021] Specifically, the base 1, serving as the mounting foundation for the mechanism, is typically machined from steel plates or aluminum alloy blocks. It has a rectangular structure with countersunk mounting holes at the four corners of the bottom. M8 hex socket head cap screws are used to fix the base 1 to the workbench or frame, ensuring installation stability. A hinge seat 3, consisting of a pair of parallel ear plates, is fixed to the base 1 by bolts or directly machined onto it. The ear plates have coaxial hinge holes with ground walls for mounting the hinge shaft 5.

[0022] The left end of the pressure arm 2 is a hinge section with a hinge hole. It passes through the hinge seat 3 of the base 1 via the hinge shaft 5, allowing the pressure arm 2 to rotate around the axis of the hinge shaft 5. The right end of the pressure arm 2 consists of a pressure head 6 and an operating section along the direction away from the hinge shaft 5. In this embodiment, the lower end of the pressure head 6 (facing the worktable) is machined with a mounting screw (with an external thread structure) for detachable mounting of the pressure head 6. A relief groove is provided at the root of the mounting screw to avoid stress concentration during thread machining. To further optimize the performance, a spherical washer can be installed between the pressure head 6 and the mounting screw to ensure uniform clamping force. The inner hole of the spherical washer is clearance-fitted with the threaded section of the pressure arm 2, and its spherical center coincides with the axis of the pressure arm 2, allowing the pressure head 6 to produce a slight adaptive deflection when clamping workpieces with irregular surfaces, adapting to the clamping requirements of uneven workpiece surfaces.

[0023] The operating section is located at the far right end of the pressure arm 2. A connecting section (e.g., cylindrical, block-shaped, etc.) is machined, and mounting holes are made for installing other components. For example, depending on the application scenario, in a manual scenario, it is connected to a handle with anti-slip texture, and the connection is achieved by a flat key or other means and locked with bolts or other components; in an automated scenario, it is connected to drive components such as cylinder piston rod or electric cylinder push rod through a pin to achieve automation.

[0024] The reset function is achieved by a torsion spring 4, which is a preloaded torsion spring 4 made of 65Mn spring steel. The torsion spring 4 is directly sleeved on the hinge shaft 5, located between the hinge seats 3 of the base 1 and on one side of the pressure arm 2. Both ends of the torsion spring 4 are bent at 90° to form pins. One end is inserted into or secured in a slot on the base 1, and the other end is inserted into or secured in a corresponding slot on the pressure arm 2. After assembly, when the pressure arm 2 is in the initial reset position, the included angle between the two arms of the torsion spring 4 is compressed to 90°, and the preload torque provided (e.g., 12~15 N·m) ensures that the pressure arm 2 is stably maintained in the reset position.

[0025] In this embodiment, the hinge shaft can be configured as a stepped shaft, with a first shoulder for axial positioning, a first shaft section for interference fit with the hinge seat hole of the base 1, a second shoulder for separating the hinge seat 3 from the pressure arm 2, a second shaft section for clearance fit with the hinge hole of the pressure arm to ensure its flexible rotation, a third shoulder for separating the pressure arm 2 from the torsion spring 4, a third shaft section with a slightly smaller diameter for fitting the torsion spring 4, with a gap between it and the inner hole of the torsion spring 4, a fourth shaft section for interference fit with the hinge seat hole on the other side, and a shaft end hole for installing an elastic retaining ring for final fixation. Through this stepped structure, the hinge seat, pressure arm, and torsion spring are precisely positioned in their respective locations along the axial direction of the hinge shaft, without interfering with each other, and can independently perform their respective functions.

[0026] The guide assembly consists of the aforementioned arc-shaped guide groove 7 and guide block 8. The arc-shaped guide groove 7 is located on the base 1 on the right side of the hinge seat 3. The arc center of the guide groove must be precisely aligned with the axis of the hinge shaft 5 to be installed later. The arc length corresponds to the rotation angle of the pressure arm 2 (70°, suitable for conventional pressing stroke). In this embodiment, 2mm high limiting bosses are provided at both ends of the guide groove to prevent the guide block 8 from sliding out. This setting will not affect the pressing operation.

[0027] The guide block 8 is fitted with the guide groove with a clearance to ensure smooth sliding without jamming. The guide block 8 is detachably fixed to the lower part of the operating section of the pressure arm 2 by a connecting rod (e.g., by thread). The connecting rod is connected to the guide block 8 or the pressure arm 2 by bolts or other means. Each component is set according to the actual connection method. After assembly, the guide block 8 is precisely embedded in the guide groove and can slide freely in the groove.

[0028] The working principle of the above device is as follows: 1) Initial state: When no external force is applied, the preload torque of the torsion spring 4 drives the pressure arm 2 to remain in the initial reset position (the pressure head 6 is away from the workpiece).

[0029] 2) Clamping process: Manual scenario: The operator pulls the handle downwards to overcome the preload torque of the torsion spring 4, driving the pressure arm 2 to rotate clockwise around the hinge shaft 5. At this time, the torsion spring 4 is further torsionped, storing elastic potential energy. Simultaneously, the guide block 8 slides synchronously along the arc-shaped guide groove 7 concentric with the hinge shaft 5, rigidly constraining the rotation trajectory of the pressure arm 2 and preventing radial movement. When the pressure head 6 contacts the workpiece, the spherical washer adaptively deflects according to the surface shape of the workpiece, so that the pressure head 6 is fully in contact with the workpiece. After applying force to the preset clamping force, the clamping state is maintained.

[0030] In automated scenarios: the cylinder or electric cylinder drives the connecting block, causing the pressure arm 2 to rotate clockwise. The subsequent pressing process is the same as in manual scenarios. The pressing force can be controlled by a pressure sensor to achieve precise pressing.

[0031] During this process, since the guide groove is coaxial with the hinge shaft 5, the guide block 8 slides smoothly in the groove without any interference, and effectively restricts the radial degree of freedom of the pressure arm 2 at any angle.

[0032] 3) Reset process: In manual operation, when the operator releases the handle, the elastic potential energy stored in the torsion spring 4 is released, driving the pressure arm 2 to rotate counterclockwise. The guide block 8 slides in the opposite direction along the guide groove, precisely guiding the pressure arm 2 to reset. When the guide block 8 contacts the limiting boss at one end of the guide groove, the pressure arm 2 returns to its initial position, and the reset is completed.

[0033] Automation scenario: Drive component reset, torsion spring 4 cooperates to drive pressure arm 2 to reset, realize automated cycle.

[0034] Therefore, the present invention adopts an automatic reset pressing mechanism with the above structure, which sets the guide groove of the guide component as an arc groove with the hinge shaft as the center, and the guide block is precisely matched with the guide groove and slidably embedded, so that when the pressure arm rotates, the guide block always slides along an arc trajectory concentric with the hinge shaft, forming a rigid constraint mechanism for the rotation trajectory, which can effectively offset the radial force generated by factors such as off-center load and unbalanced operation, and completely eliminate the radial movement and jamming of the pressure arm; A torsion spring is used as the reset spring and is directly sleeved on the hinge shaft of the pressure arm. The two ends of the torsion spring are directly fixed to the slots on the pressure arm through the base, which minimizes the force transmission path and avoids the force transmission loss caused by the installation structure of the tension / compression spring. At the same time, the torsion spring and the hinge shaft are coaxially integrated, requiring no additional installation space.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although the utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solution of this utility model, and these modifications or equivalent substitutions cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of this utility model.

Claims

1. An automatic reset clamping mechanism, characterized in that: The device includes a base and a pressure arm, a guide assembly, and a return spring mounted on the base. A hinge seat is fixedly mounted on the base. The left end of the pressure arm is hinged to the hinge seat via a hinge shaft. The right end of the pressure arm is sequentially configured as a pressure head section and an operating section in a direction away from the hinge shaft. The lower end of the pressure head section is provided with a pressure head for pressing the workpiece. The return spring is a torsion spring, which is sleeved on the hinge shaft. Both ends of the torsion spring are fixed to the base and the pressure arm, respectively. The guide assembly includes a guide groove formed on the base and a guide block connected to the pressure arm. The guide block is slidably embedded in the guide groove, and the guide groove is configured as an arc-shaped groove with the axis of the hinge shaft as the center.

2. The automatic reset clamping mechanism according to claim 1, characterized in that: The torsion spring is a preloaded torsion spring.

3. The automatic reset clamping mechanism according to claim 1, characterized in that: The guide block is adapted to the guide groove, and the guide block and the operating section of the pressure arm are detachably connected by a connecting rod.

4. The automatic reset clamping mechanism according to claim 1, characterized in that: The pressure head is detachably connected to the lower end of the pressure head section of the pressure arm.

5. The automatic reset clamping mechanism according to claim 1, characterized in that: A spherical washer is provided between the pressure head and the pressure arm.

6. The automatic reset clamping mechanism according to claim 1, characterized in that: Both the base and the side wall of the pressure arm are provided with slots for fixing the torsion spring.

7. The automatic reset clamping mechanism according to claim 1, characterized in that: The operating section of the pressure arm is provided with a handle fixed to the pressure arm, and the surface of the handle is provided with anti-slip texture.

8. The automatic reset clamping mechanism according to claim 1, characterized in that: The operating section of the pressure arm is provided with a connecting block, and the pressure arm is connected to the drive assembly through the connecting block.

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