Clamping mechanism and conveying device

Abstract

The present invention provides a clamping mechanism and a conveying device equipped therewith, which allows the operator to adjust the overall balance of the workpiece and clamping mechanism without manual adjustment, and which also allows for easy adjustment of the clamping force. [Solution] The clamping mechanism 1 comprises a sling 6, a frame 2, a linear drive unit 5, a fixed clamp section 3 having a fixed lifting section 9, and a movable clamp section 4 having a movable lifting section 13. The movable clamp section 4 is configured to move toward the fixed clamp section 3 when the sling 6, which is connected to the fixed lifting section 9 and the movable lifting section 13, is lifted. The linear drive unit 5 is configured to generate thrust toward the fixed clamp section 3 by causing the movable clamp section 4 to move linearly in the extending direction of the frame 2.

Description

Technical Field

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[0001] The present disclosure relates to a clamping mechanism and a conveying device.

Background Art

[0002] As a clamping mechanism used in a conveying device for heavy objects, a hanging clamp that sandwiches and grips both ends of a workpiece by utilizing the weight of the workpiece is known. Regarding such a clamping mechanism, Japanese Patent Application Laid-Open No. 9-86863 (Patent Document 1) describes a mechanism capable of steplessly changing the clamping width and stepwise changing the hanging position of the main body.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the mechanism described in the above publication, when lifting a workpiece, it is necessary to arrange the hanging clamp after grasping the center-of-gravity position of the workpiece. However, in a processing site with a small quantity and diverse types of products, the center-of-gravity positions of the workpieces are diverse and difficult to grasp. Therefore, the adjustment of the gripping position is performed based on the intuition of the operator. Accordingly, manual setup change work occurs, and it is necessary for the operator to manually adjust the overall balance of the workpiece and the clamping mechanism.

[0005]

特許請求の範囲

[0006]

[0007]

[0008]

[0009] [Figure 1] [Figure 2] [Figure 3] [Figure 4]Furthermore, when lifting a workpiece, the entire workpiece and clamping mechanism rotate so that the center of gravity of the clamped workpiece is aligned with the lifting direction. A sufficiently large clamping force must be applied to prevent the workpiece from coming loose from the clamping mechanism due to the force moment generated at this time. The clamping force is determined by the weight of the workpiece and its stroke. Since the operator manually adjusts the stroke to balance the entire workpiece and clamping mechanism, it is not possible to quantitatively adjust the clamping force. Therefore, adjusting the clamping force is difficult.

[0006] This disclosure has been made in view of the above-mentioned problems, and its purpose is to provide a clamping mechanism and a conveying device equipped therewith that allow the overall balance of the workpiece and clamping mechanism to be adjusted without manual adjustment by the operator, and that the clamping force can be easily adjusted. [Means for solving the problem]

[0007] The clamping mechanism of this disclosure comprises a sling, a frame, a linear drive unit fixed to the frame along the extending direction of the frame, a fixed clamping section fixed to the frame and having a fixed lifting section to which the sling is connected, and a movable clamping section connected to the linear drive unit so as to be movable along the linear drive unit, facing the fixed clamping section and having a movable lifting section to which the sling is connected. The movable clamping section is configured to move toward the fixed clamping section when the sling connected to the fixed lifting section and the movable lifting section is lifted. The linear drive unit is configured to generate thrust toward the fixed clamping section by causing the movable clamping section to move linearly in the extending direction of the frame. [Effects of the Invention]

[0008] The clamping mechanism of this disclosure allows the operator to adjust the overall balance of the workpiece and the clamping mechanism without manual adjustment, and also facilitates adjustment of the clamping force. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic front view showing the clamping mechanism according to Embodiment 1. [Figure 2] This is a schematic perspective view showing the transport device according to Embodiment 1. [Figure 3] This is a flowchart illustrating the transport method according to Embodiment 1. [Figure 4] This is a schematic front view showing the clamping mechanism according to Embodiment 2. [Modes for carrying out the invention]

[0010] The embodiments will be described below with reference to the figures. In the following, the same or corresponding parts will be denoted by the same reference numerals, and redundant explanations will not be repeated.

[0011] Embodiment 1. Referring to Figure 1, the configuration of the clamp mechanism 1 according to Embodiment 1 will be described.

[0012] Figure 1 is a schematic front view showing the clamping mechanism 1 according to Embodiment 1. The clamping mechanism 1 according to Embodiment 1 is used to lift and transport a workpiece upward using a crane or chain block or the like.

[0013] The clamping mechanism 1 comprises a frame 2, a fixed clamping section 3, a movable clamping section 4, a linear drive unit 5, and a sling 6.

[0014] Frame 2 secures the fixed clamp section 3 and the linear drive unit 5. Frame 2 is made of a material and thickness that provides sufficient strength against the mass of the workpiece and the clamping force. The fixed clamp section 3 and the movable clamp section 4 are positioned facing each other in the extending direction of frame 2. In this embodiment, the extending direction of frame 2 is the longitudinal direction of frame 2.

[0015] The fixed clamp section 3 has a fixed arm 7, a fixed pad 8, a fixed lifting section 9, and a height-direction contact surface section 10. The fixed clamp section 3 is fixed to the frame 2. Specifically, the fixed arm 7 is fixed to the frame 2. The fixed arm 7 has a surface perpendicular to the frame 2. The fixed pad 8 is installed on this surface. The fixed arm 7 has sufficient strength against the mass of the workpiece and the clamping force. The fixed pad 8 is made of an elastic material. The fixed pad 8 is made using an elastic material that expands and contracts in the direction to which the gripping force of the workpiece is applied. A linear drive unit 5 is positioned to move linearly in the direction of approaching and moving away from the fixed pad 8. The fixed lifting section 9 is installed on the fixed arm 7. A sling 6 is connected to the fixed lifting section 9. The fixed lifting section 9 is connected to the hook of a crane or chain block through the sling 6. Multiple fixed lifting sections 9 may be installed in the depth direction of the paper in Figure 1. The fixed lifting section 9 is designed to support the mass of the clamping mechanism 1 and the workpiece, and therefore should be sufficiently strong to withstand the mass of the clamping mechanism 1 and the workpiece. The height-direction contact surface 10 has an L-shaped sheet metal form. The height-direction contact surface 10 is positioned on the fixed arm 7 so as to have a surface perpendicular to the fixed pad 8. The height-direction contact surface 10 is sufficiently small relative to the width of the workpiece. The height-direction contact surface 10 has a sufficiently high coefficient of friction relative to the material of the workpiece.

[0016] The movable clamp section 4 includes a movable arm 11, a movable pad 12, a movable lifting section 13, and a locking mechanism 14. The movable clamp section 4 faces the fixed clamp section 3. The movable clamp section 4 is connected to the linear drive unit 5 so as to be movable along the linear drive unit 5. The movable clamp section 4 is subordinate to the linear drive unit 5. The movable clamp section 4 moves toward and away from the fixed clamp section 3 in accordance with the operation of the linear drive unit 5. The movable arm 11 has a surface perpendicular to the frame 2. The movable pad 12 is positioned on this surface. The movable arm 11 has sufficient strength against the mass of the workpiece and the clamping force. The movable pad 12 is made of an elastic material. The movable pad 12 is made of an elastic material that expands and contracts in the direction in which the gripping force of the workpiece is applied. The movable pad 12 is located collinearly with the fixed pad 8 and the linear drive unit 5. The movable pad 12 is positioned so as to face the fixed pad 8. The movable lifting section 13 is installed on the movable arm 11. A sling 6 is connected to the movable lifting section 13. The movable clamp section 4 is configured to move toward the fixed clamp section 3 when the sling 6 connected to the fixed lifting section 9 and the movable lifting section 13 is lifted. The movable lifting section 13 is connected to the hook of a crane or chain block through the sling 6. The number of movable lifting sections 13 is equal to the number of fixed lifting sections 9. The movable lifting section 13 is designed to support the mass of the clamping mechanism 1 and the workpiece, and therefore must be sufficiently strong against the mass of the clamping mechanism 1 and the workpiece. The locking mechanism 14 is fixed to the movable arm 11. The locking mechanism 14 is configured to fix the movable clamp section 4 to at least one of the frame 2 and the linear drive unit 5. The locking mechanism 14 has a movable part inside that is actuated by a lead screw or link mechanism. When this movable part is actuated, it generates a pressing force on the frame 2 or the linear drive unit 5. The movable clamping portion 4 is fixed in place by friction generated between the locking mechanism 14 and the frame 2 or the linear drive unit 5. The material and pressing force of the locking mechanism 14 are set so that when the locking mechanism 14 is operated with a clamping force applied to the workpiece, the clamping force does not exceed the frictional force and cause it to move.The locking mechanism 14 has sufficient strength against the mass of the workpiece and the clamping force.

[0017] The linear drive unit 5 is fixed to the frame 2 along the extending direction of the frame 2. The linear drive unit 5 is configured to generate a thrust force toward the fixed clamping part 3 by linearly moving the movable clamping part 4 in the extending direction of the frame 2. The linear drive unit 5 is configured to move the movable clamping part 4 steplessly. For the linear drive unit 5, one with a sufficiently high rigidity and driving force against the weight of the workpiece is selected. The linear drive unit 5 may be configured such that an operator can manually operate it by installing a handle on a feed screw, using a guide and a guide block. Also, the linear drive unit 5 may be operated by connecting an electric motor instead of the handle.

[0018] The sling 6 has a wire rope or a chain for the total number of the fixed lifting part 9 and the movable lifting part 13. The sling 6 has a ring R in a shape connectable to a hook of a crane or a chain block. The ring R is configured in an annular shape. A wire rope or a chain is passed through the hole of the ring R. For the components of the sling 6, those having sufficient strength against the mass of the workpiece and the clamping force are selected.

[0019] Referring to FIG. 2, the configuration of the transfer device 15 provided with the clamping mechanism 1 as a gripping mechanism will be described. FIG. 2 is a perspective view schematically showing the transfer device 15 according to the first embodiment. The transfer device 15 includes a clamping mechanism 1, a crane 16, a supply device 18, and a discharge device 19. The crane 16 has a gantry crane shape in FIG. 2, but may have a shape such as a jib crane.

[0020] The supply device 18 has a function of conveying the workpiece 17 from the previous process to within the movable range of the crane 16 by means of a conveyor or the like. The discharge device 19 has a function of conveying the workpiece 17 conveyed by the clamp mechanism 1 and the crane 16 from within the movable range of the crane 16 to the next process by means of a conveyor or the like.

[0021] Next, referring to FIG. 3, the conveying method according to Embodiment 1 will be described. FIG. 3 is a flowchart schematically showing the conveying method according to Embodiment 1. Specifically, FIG. 3 is a flowchart showing the procedure from when the conveying device 15 described in FIG. 2 clamps the workpiece until the conveyance of the workpiece is completed.

[0022] When the conveying method according to Embodiment 1 starts, a gripping preparation step (step S101) is performed. In the gripping preparation step (step S101), the crane 16 is operated to approach the clamp mechanism 1 to the workpiece conveyed to within the movable range of the crane 16 by the supply device 18. At this time, regarding the clamp mechanism 1, the lock mechanism 14 does not operate, and the movable clamp portion 4 is arranged so that the distance between the workpiece contact surfaces of the fixed pad 8 and the movable pad 12 is larger than the workpiece width.

[0023] Following the gripping preparation step (step S101), the gripping step (step S102) is performed. In the gripping step (step S102), the fixed pad 8 and the height-direction contact surface 10 are brought into contact with the workpiece to perform rough positioning, and the movable clamp part 4 is pressed against the workpiece by the operation of the linear drive unit 5. At this time, the movable lifting part 13 moves in accordance with the movable clamp part 4, so the entire clamping mechanism 1 is automatically balanced. Subsequently, the linear drive unit 5 is operated to adjust the clamping force so that an appropriate clamping force is applied to the weight of the workpiece and the rigidity of the clamping position. Finally, with force applied to the workpiece, the locking mechanism 14 is activated, and the movable clamp part 4 is fixed by friction between the locking mechanism 14 and the frame 2. At this time, the clamping force is maintained even if the power to the linear drive unit 5 is cut off. For example, if we assume that the linear drive unit 5 consists of a lead screw, a guide, and a guide block, and the power source is an operator who operates a handle, the operator operates the handle to clamp the workpiece with the thrust of the lead screw and activates the locking mechanism 14 while checking the value of the force sensor. At this time, the clamped state is maintained even if the operator releases their hand from the handle.

[0024] The gripping process (step S102) is followed by the transport process (step S103). In the transport process (step S103), the crane 16 is operated to transport the lifted workpiece to the discharge device 19. At this time, the clamping force applied to the workpiece by the clamping mechanism 1 is kept constant and is not affected by changes in acceleration in the direction of gravity, such as vibrations and shocks during workpiece transport.

[0025] Following the transport process (step S103), a release process (step S104) is performed. In the release process (step S104), the clamping force applied to the workpiece is released. The lifted workpiece is lowered onto the discharge device 19, and the lock mechanism 14 is released, allowing the movable clamp part 4 to move. After that, the released workpiece is transported to the next process by the discharge device 19. This completes the transport method according to Embodiment 1.

[0026] Next, the effects and advantages of Embodiment 1 will be described. According to the clamping mechanism 1 of Embodiment 1, the movable clamping section 4 is configured to move toward the fixed clamping section 3 when the sling 6 connected to the fixed lifting section 9 and the movable lifting section 13 is lifted. When a clamping force is applied to the workpiece, the movable lifting section 13 moves in accordance with the movable clamping section 4. At this time, the lifting position is automatically changed to the center line between the strokes as the stroke of the clamping mechanism 1 changes, so the entire workpiece and clamping mechanism 1 are balanced without manual adjustment. Therefore, the overall balance of the workpiece and clamping mechanism 1 can be adjusted without manual adjustment by the operator.

[0027] Furthermore, the workpiece can be clamped by moving the movable clamping section 4 while the workpiece is pressed against the clamping surface of the fixed clamping section 3 and positioned. Therefore, the gripping position in the depth direction can be easily adjusted. The depth direction is perpendicular to both the extending direction and the direction of gravity of the frame 2.

[0028] Furthermore, the linear drive unit 5 is configured to generate thrust toward the fixed clamp section 3 by linearly moving the movable clamp section 4 in the extending direction of the frame 2. By operating the linear drive unit 5, an arbitrary clamping force is applied to the workpiece. Therefore, the clamping force can be adjusted quantitatively. This makes it easy to adjust the clamping force. Thus, by adjusting the clamping force so that the workpiece does not come off the clamping mechanism 1, the gripping of the workpiece by the clamping mechanism 1 is stabilized.

[0029] Furthermore, since the workpiece is clamped by the thrust of the linear drive unit 5, the clamping force applied to the workpiece is maintained at a constant level, independent of acceleration in the direction of gravity such as vibrations and shocks during workpiece transport. Therefore, because there are fewer constraints on the means of moving the clamping force, the clamping mechanism 1 is versatile.

[0030] According to the clamping mechanism 1 of Embodiment 1, the linear drive unit 5 is configured to move the movable clamping portion 4 steplessly. This allows for stepless adjustment of the applied clamping force. Furthermore, since the clamping width can be changed steplessly, setup changes to match the size of the workpiece are not required.

[0031] According to the clamping mechanism 1 of Embodiment 1, the locking mechanism 14 is configured to fix the movable clamping portion 4 to at least one of the frame 2 and the linear drive unit 5. Therefore, it is possible to maintain the clamping force applied when the locking mechanism 14 is activated. Consequently, any desired clamping force can be maintained, allowing for adjustment according to the shape and material of the workpiece.

[0032] The conveying device 15 according to Embodiment 1 is equipped with the clamping mechanism 1 described above. Therefore, the overall balance of the workpiece and the clamping mechanism 1 can be adjusted without manual adjustment by the operator, and the clamping force can be easily adjusted.

[0033] Embodiment 2. Embodiment 2 has the same configuration, transport method, and effects as Embodiment 1 unless otherwise specified. Therefore, the same reference numerals are used for components identical to those in Embodiment 1, and their descriptions are not repeated.

[0034] Referring to Figure 4, the configuration of the clamp mechanism 1 according to Embodiment 2 will be described. In the clamp mechanism 1 according to Embodiment 2, the shapes of the fixed pad 8 and the movable pad 12 are different from those of the clamp mechanism 1 according to Embodiment 1.

[0035] The fixed pad 8 and the movable pad 12 each have elastic properties. The fixed pad 8 and the movable pad 12 are configured to become thicker as they are directed downwards in the direction of gravity. The fixed pad 8 has a shape that becomes thicker as it extends from the linear drive unit 5 side outwards. Similarly, the movable pad 12 also has a shape that becomes thicker as it extends from the linear drive unit 5 side outwards.

[0036] According to the clamping mechanism 1 of Embodiment 2, the fixed pad 8 and the movable pad 12 each have elastic materials and are configured to become thicker as they move downward in the direction of gravity. Therefore, even if at least one of the frame 2, the fixed clamping portion 3, and the movable clamping portion 4 deforms due to the reaction force of the clamping force, the contact area between the workpiece and the fixed pad 8 and the movable pad 12 is not significantly impaired. Thus, stable gripping and transport becomes possible.

[0037] The above embodiments can be combined as appropriate. The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of this disclosure is indicated by the claims rather than the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended.

[0038] The various aspects of this disclosure are summarized below as an appendix. (Note 1) Sling and Frame and, A linear drive unit fixed to the frame along the extending direction of the frame, A fixing clamp section having a fixed lifting section that is fixed to the frame and to which the sling is connected, It comprises a movable clamp section which is connected to the linear drive unit so as to be movable along the linear drive unit, faces the fixed clamp section, and has a movable lifting section to which the sling is connected, The movable clamp is configured to move toward the fixed clamp when the sling connected to the fixed lifting section and the movable lifting section is lifted. The linear drive unit is configured to generate thrust toward the fixed clamp by linearly moving the movable clamp in the extending direction of the frame, thereby generating thrust toward the fixed clamp.

[0039] (Note 2) The clamping mechanism described in Appendix 1, wherein the linear drive unit is configured to move the movable clamp portion in a stepless manner.

[0040] (Note 3) The movable clamp portion includes a locking mechanism. The clamping mechanism according to Appendix 1 or 2, wherein the locking mechanism is configured to fix the movable clamp portion to at least one of the frame and the linear drive unit.

[0041] (Note 4) The aforementioned fixing clamp portion includes a fixing pad, The movable clamp portion includes a movable pad, The clamping mechanism according to any one of the appendices 1 to 3, wherein the fixed pad and the movable pad each have an elastic body and are configured to become thicker as they move downward in the direction of gravity.

[0042] (Note 5) A conveying device equipped with the clamping mechanism described in any one of the appendices 1 to 4. [Explanation of Symbols]

[0043] 1 Clamping mechanism, 2 Frame, 3 Fixed clamping section, 4 Movable clamping section, 5 Linear drive unit, 6 Sling, 7 Fixed arm, 8 Fixed pad, 9 Fixed lifting section, 10 Height direction contact surface section, 11 Movable arm, 12 Movable pad, 13 Movable lifting section, 14 Locking mechanism, 15 Conveying device, 16 Crane, 17 Workpiece, 18 Supply device, 19 Discharge device, S101 Gripping preparation process, S102 Gripping process, S103 Conveying process, S104 Release process.

Claims

1. Sling and Frame and, A linear drive unit fixed to the frame along the extending direction of the frame, A fixing clamp section having a fixed lifting section that is fixed to the frame and to which the sling is connected, It comprises a movable clamp section which is connected to the linear drive unit so as to be movable along the linear drive unit, faces the fixed clamp section, and has a movable lifting section to which the sling is connected, The movable clamp is configured to move toward the fixed clamp when the sling connected to the fixed lifting section and the movable lifting section is lifted. The linear drive unit is configured to generate thrust toward the fixed clamp by linearly moving the movable clamp in the extending direction of the frame, thereby generating thrust toward the fixed clamp.

2. The clamping mechanism according to claim 1, wherein the linear drive unit is configured to move the movable clamp portion steplessly.

3. The movable clamp portion includes a locking mechanism. The clamping mechanism according to claim 1, wherein the locking mechanism is configured to fix the movable clamp portion to at least one of the frame and the linear drive unit.

4. The aforementioned fixing clamp portion includes a fixing pad, The movable clamp portion includes a movable pad, The clamping mechanism according to claim 1, wherein the fixed pad and the movable pad each have an elastic body and are configured to become thicker as they move downward in the direction of gravity.

5. A conveying device comprising the clamping mechanism described in any one of claims 1 to 4.

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