JP7707045B2 - Article gripping device - Google Patents

Description

The present invention relates to an object gripping device used as a means of holding and transporting workpieces on a factory production line.

Conventionally, in factory production lines, workpieces (items) are held and transported using vacuum suction devices. Such vacuum suction devices use a suction pad, the inside of which is made negative pressure by a vacuum generator, to adhere to the workpiece, and the workpiece is held in place using suction force (Patent Document 1).

While such vacuum suction devices have the advantage of being lightweight and compact, they have the problem that if the surface of the object being held is uneven, air leaks through the unevenness, making it impossible to hold the object properly.

Furthermore, because the holding power of such a vacuum suction device is insufficient, it is difficult to hold the item stably if the weight of the item to be held is above a certain level.

In this regard, Patent Document 2 discloses a part holding device that can hold an object by driving a toggle link mechanism with a piston that is activated by vacuum pressure. This device is capable of providing a large gripping force while utilizing limited vacuum pressure.

However, when the piston moves inside the cylinder, friction occurs between the two, resulting in mechanical losses over long periods of use and the need to replace worn parts.

In addition, when it is necessary to transport items using a gripping device, it is essential that the device itself be lightweight, but devices equipped with cylinders and pistons have a complex structure, which can impair the lightweight design and hinder smooth transportation.

Patent Publication 2013-107174 JP 11-340688 A

The present invention aims to overcome these shortcomings of conventional item holding devices, and to provide an item holding device that is lightweight and compact, yet capable of securely holding items, and that can significantly reduce mechanical loss caused by long-term use.

The present invention solves the above problems and provides an article gripping device that includes a suction pad (301) with a bellows structure that can expand and contract in the vertical direction by suction means, an attached part (201) that is in close contact with the lower end opening (302) of the suction pad (301) and is formed so as to be able to move up and down along with the expanding and contracting suction pad (301), a link mechanism that is driven by the up and down movement of the attached part (201), and a pair of left and right gripping parts (114) that perform opening and closing operations via the link mechanism.

The present invention also provides an article gripping device, characterized in that the link mechanism includes a base portion (101), a pair of bracket portions (111) that are provided below the base portion (101) via driven links (121) and (122) on the left and right sides and are pivotable left and right relative to the base portion (101), and a gripping portion (114) is formed on the bracket portion (111).

Furthermore, the present invention is an article gripping device characterized in that the link mechanism includes a joint pin (135) provided on the attracted portion (201), a slide joint pin (134) guided by a long hole portion (105) formed in the base portion (101) so as to be movable up and down, a joint pin (133) provided on the bracket portion (111), a drive link (124) whose upper end is connected to the joint pin (135) and whose lower end is connected to the slide joint pin (134), and a driven link (123) whose upper end is connected to the slide joint pin (134) and whose lower end is connected to the joint pin (133).

The article gripping device of the present invention moves the attached part up and down using a suction pad that expands and contracts due to the suction means, and opens and closes the gripping part using a link mechanism driven by the movement of the attached part, making it possible to make the gripping device lighter and more compact.

In addition, the article gripping device of the present invention uses a suction pad with a bellows structure as a driving means, which can significantly reduce mechanical loss compared to gripping devices that use cylinders and pistons.

In addition, the item gripping device of the present invention has a bellows structure for the suction pad, making it highly versatile and adaptable to different work sizes.

In addition, because the article gripping device of the present invention is designed to utilize a bellows-type suction pad, parts can be easily replaced if damaged, unlike devices with complex structures that include cylinders and pistons.

In addition, because the suction pad of the article gripping device of the present invention has a bellows structure, the link mechanism can increase the speed at which the gripping part opens and closes by utilizing repulsive force.

FIG. 2 is a front view of the article gripping device according to the present invention, showing the gripping portion in an open state. 1 is a front view of an article gripping device according to the present invention, showing a state in which the gripping parts are closed and gripping an article. FIG. FIG. 2 is a side view of an article gripping device according to the present invention, in which illustration of some components is omitted. FIG. 2 is a central vertical cross-sectional view of an article gripping device according to the present invention, in which some components are omitted.

Below, embodiments of the object gripping device of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to these embodiments.

Figures 1 and 2 are front views of the article gripping device 1 according to the present invention, Figure 3 is a side view, and Figure 4 is a central vertical cross-sectional view. Note that in Figures 3 and 4, some components have been omitted to facilitate understanding of the link mechanism. As shown in the figures, the article gripping device 1 of the present invention comprises an attached part 201 formed to be movable up and down, a suction pad 301 for moving the attached part 201 up and down, a link mechanism that is driven in accordance with the up and down movement of the attached part 201, and a pair of gripping parts 114 that perform opening and closing operations by the link mechanism. Each part will be described below.

The base portion 101, which constitutes part of the link mechanism, is provided with a top plate 102 formed longitudinally in the left-right direction, and vertical wall portions 103 hanging down from the front and rear ends of the top plate 102, and is formed in a roughly U-shape in side view. The central portion of the vertical wall portion 103 further protrudes downward to form a protrusion 104, and a vertically long hole portion 105 is formed from the vertical wall portion 103 to the protrusion 104. A slide joint pin 134 is installed in the long hole portion 105 to span the vertical wall portions 103 on the front and rear sides.

A pair of support members 401 are erected on both the left and right sides of the top plate 102 of the base part 101. The support member 401 consists of an intermediate part 402 formed longitudinally in the vertical direction, and an upper mounting part 403 and a lower mounting part 404 formed by bending both ends of the intermediate part 402 horizontally. The support member 401 is fixed to the top plate 102 at the lower mounting part 404 by a bolt 405. In addition, one or more sides of the support member 401 have an open structure, which makes it easy to replace the suction pad 301.

A plate 406 is fixed to the upper mounting portion 403 of the support member 401 by a bolt 405. The plate 406 is supported in a horizontal position by the support member 401 at a predetermined distance from the top plate 102 of the base 101.

A hole is drilled in the center of the plate 406, and a pipe 501 is erected on the upper surface of the portion where the hole is provided so as to communicate with the hole. The upper end of the pipe 501 is connected to a hose 503 via an elbow joint 502. The other end of the hose 503 is further connected to a suction means such as a vacuum generator.

A tube-shaped suction pad 301 with an expandable bellows structure and an opening at the bottom end is provided to hang down from the underside of the portion of the plate 406 where the hole is provided. The upper opening of the suction pad 301 is connected to the hole of the plate 406, and the lower opening 302 is provided so as to be in close contact with the top wall 202 of the suction target 201. Note that, as long as the lower opening 302 of the suction pad 301 can be supported at a predetermined height from the suction target 201 so that it is in close contact with the top wall 202, the support means for the suction pad 301 is not limited to the support member 401 and the plate 406, and other support means, such as a casing that houses the suction pad 301 and the suction target 201, may be used. Also, as long as the lower opening 302 of the suction pad 301 can be constantly maintained in close contact with the top wall 202 of the suction target 201, the two do not need to be fixed to each other.

The adsorbed portion 201 has a top wall portion 202 having a flat surface wider than the lower opening 302 of the suction pad 301, and hanging wall portions 203 hanging down from the front and rear ends of the top wall portion 202, and is formed in a roughly U-shape in side view. A joint pin 135 is installed between the front and rear hanging wall portions 203, and the drive link 124 is connected so as to hang down from the joint pin 135. Note that, in this embodiment, the adsorbed portion 201 is formed in a roughly U-shape, but the shape is not limited to this, and it is sufficient that the suction pad 301 has a flat surface that can be adsorbed.

As shown in FIG. 1, in the standby state of the article gripping device 1 of the present invention, the bottom end 204 of the attracted part 201 is in contact with the top plate 102 of the base part 101. The attracted part 201 is provided so as to be movable up and down relative to the base part 101; more specifically, in the state of FIG. 1, the attracted part 201 is at the lowest position, and in the state of FIG. 2, it is at the highest position, and can move up and down between the highest and lowest positions.

The drive link 124, whose upper end is connected to the joint pin 135, is inserted into a notch 106 formed in the top plate 102 of the base part 101, protrudes below the top plate 102, and is connected at its lower end to the slide joint pin 134 of the base part 101.

As shown in Figures 3 and 4, the drive links 124 in this embodiment are provided in four rows, one each at the front and rear of the slide joint pin 134 and the joint pin 135. By providing four drive links 124 at the front and rear in this way, sufficient strength and structural stability can be ensured, but the number of drive links 124 is not limited to this, and may be two, for example.

Next, the link mechanism of the article gripping device 1 according to the present invention will be described in detail. The link mechanism of the present invention is a mechanism for opening and closing a pair of gripping parts 114, in which the base part 101 serves as a fixed link, and a pair of left and right bracket parts 111 are provided below the base part 101. The bracket part 101 has a bottom plate 112 formed longitudinally in the left-right direction, and vertical wall parts 113 suspended from the front and rear ends of the bottom plate 112, and is formed in a roughly U-shape in side view. Furthermore, the bottom plate 112 is bent so that one side part on which the vertical wall part 113 is not provided extends and hangs down as it is, forming the gripping part 114.

In this embodiment, the gripping parts 114 are formed so as to hang down from the opposing inner edges of the pair of bracket parts 101 provided on the left and right, but depending on the size of the item to be held, the gripping parts 114 may be formed so as to hang down from the opposite edge of the bracket parts 101, i.e., the outer edge. Also, in this embodiment, the bracket parts 101 and the gripping parts 114 are formed integrally, but they may be formed separately and then fixed and joined together.

The bracket portion 111 is connected to the base portion 101 via driven links 121, 122, and 123. The driven links 121, 122, and 123 are provided on the left and right sides of the base portion 101. Of these, the driven links 121 and 122 are arranged parallel to each other, and their upper ends are connected to joint pins 131 and 132 that are installed on the left and right sides of the vertical wall portion 103 of the base portion 101. In addition, their lower ends are connected to joint pins 131 and 132 that are installed on the vertical wall portion 113 of the bracket portion 111. The bracket portion 111 can swing left and right relative to the base portion 101 by the parallel driven links 121 and 122.

The driven links 123 are provided on the left and right sides of the base 101, and their upper ends are connected to slide joint pins 134 installed in the long holes 105 of the base 101. Their lower ends are connected to joint pins 133 installed in the vertical wall 113 of the bracket 111.

As shown in Figures 3 and 4, the driven links 121, 122, and 123 are provided in pairs at the front and rear of the base portion 101 and bracket portion 111. Washers 136 are also fitted to each joint pin between adjacent links and between the vertical wall portions 103, 113, and 203 to prevent misalignment of the connected drive link 124 and driven links 121, 122, and 123.

Next, a series of operations of the article gripping device 1 according to the present invention will be described. In FIG. 1, the gripping unit 114 is in an open standby state. To change from this state to the gripping state in FIG. 2 where the gripping unit 114 is closed, first, the suction means connected to the hose 503 is activated, and the air in the suction pad 301 is sucked through the pipe 501.

The lower opening 302 of the suction pad 301 is in close contact with the top plate 202 of the suction target 201, so there is no room for air to enter the suction pad 301 from the outside, and negative pressure is created inside the suction pad 301 as the suction means draws air.

The suction pad 301 has a flexible bellows structure, so it starts to contract as the pressure inside becomes negative. And because the upper opening of the suction pad 301 is fixed to the plate 406, the direction of contraction also becomes upward, and the lower opening 302 rises. As a result, the suction target part 201 to which the lower opening 302 is suctioned is lifted upward.

When the attracted part 201 is lifted, the driving link 124 connected to the joint pin 135 of the attracted part 201 is also lifted, and further, the slide joint pin 134 connected to the lower end of the driving link 124 is also guided by the long hole portion 105 and moves upward.

As the slide joint pin 134 moves upward in this manner, the upper ends of the driven links 123 connected to the slide joint pin 134 are also lifted upward. At this time, the lower ends of the left and right driven links 123 connected to the joint pin 133 move toward the center as if pulled by the slide joint pin 134. This causes the left and right bracket parts 111 to be drawn closer to each other.

Figure 2 shows the state in which the suction pad 301 is most contracted due to suction by the suction means. In this state, the suction target portion 201 is at the top, and the left and right gripping portions 114 are also at their closest to each other. In this state, it is possible to grip the article X, but depending on the size of the article X to be gripped, the left and right gripping portions 114 do not have to be at their closest to each other, and the suction target portion 201 does not have to be at the top.

To return from the state shown in FIG. 2 to the state shown in FIG. 1 and release the gripped article, the suction by the suction means is stopped and air is returned to the suction pad 301. This causes the inside of the suction pad 301, which was in a negative pressure state, to return to the same state as the external air pressure, and the suction pad 301 itself has an elastic restoring force and the weight of the suction pad 301 and other components causes the suction pad 301 to move downward.

As the attracted part 201 moves downward, the driving link 124 connected to the joint pin 135 of the attracted part 201 is pushed downward. As a result, the slide joint pin 134 connected to the lower end of the driving link 124 is guided by the long hole portion 105 and moves downward.

As the slide joint pin 134 moves downward in this manner, the upper ends of the driven links 123 connected to the slide joint pin 134 are also pushed downward. At this time, the lower ends of the left and right driven links 123 connected to the joint pin 133 move to the left and right as if being pushed by the slide joint pin 134, which causes the left and right bracket parts 111 to move in directions away from each other.

The article gripping device 1 according to the present invention can be attached to a conveying device in a production line by means of an attachment member 601. The attachment member 601 is made by combining an approximately U-shaped upper member 602 and a lower member 603 from above and below, and the lower member 603 is joined to a plate 406, and is fixed to the conveying device by bolt fastening holes provided on the sides of the upper member 602 and the lower member 603.

As described above, the article gripping device 1 according to the present invention is lightweight and compact because it has a structure in which the link mechanism is operated by the expansion and contraction of the suction pad 301 without using a cylinder or piston, and it enables smooth transport of articles even when attached to the transport device of a production line.

In addition, the article gripping device 1 according to the present invention is structured to utilize a bellows-structured suction pad 301, and therefore, unlike devices with complex structures including cylinders and pistons, parts can be easily replaced in the event of damage, etc.

Furthermore, in the article gripping device 1 according to the present invention, the suction pad 301 has a bellows structure with elastic restoring force, so that the repulsive force can be utilized to increase the speed at which the gripping part 114 is opened and closed by the link mechanism.

REFERENCE SIGNS LIST 1 ... Article gripping device 101 ... Base portion 102 ... Top wall portion 103 ... Vertical wall portion
104 ... Projection portion 105 ... Long hole portion 106 ... Notch 111 ... Bracket portion 112 ... Bottom wall portion 113 ... Vertical wall portion
114 ... gripping portion 121 ... driven link 122 ... driven link 123 ... driven link 124 ... driving link 131 ... joint pin 132 ... joint pin 133 ... joint pin
DESCRIPTION OF SYMBOLS 134 ... Slide joint pin 135 ... Joint pin 201 ... Adsorbed portion 202 ... Top wall portion 203 ... Vertical wall portion 204 ... Lower end portion 301 ... Adsorption pad 302 ... Lower opening 401 ... Support member 402 ... Middle portion 403 ... Upper mounting portion 404 ... Lower mounting portion 405 ... Bolt 406 ... Plate 501 ... Pipe 502 ... Elbow joint portion 503 ... Hose 601 ... Mounting member 602 ... Upper portion of member 603 ... Lower portion of member X ... Article

Claims (3)

The device comprises a suction pad (301) having a bellows structure that can expand and contract in the vertical direction by a suction means, an attracted part (201) that is in close contact with a lower end opening (302) of the suction pad (301) and is formed so as to be movable up and down along with the expanding and contracting suction pad (301), a link mechanism that is driven in accordance with the up and down movement of the attracted part (201), and a pair of left and right gripping bodies (114 , 111 ) that are provided so as to be swingable left and right by the link mechanism ,
The link mechanism includes:
a drive link (124) connected to the attracted portion (201) and moving up and down together with the attracted portion (201);
a pair of driven links (123) provided on the left and right of one of the driving links (124), each of which has its upper end connected to the driving link (124) and its lower end connected to the gripping body (114, 111);
An article gripping device comprising: The article gripping device according to claim 1, characterized in that the link mechanism comprises a base portion (101), a pair of bracket portions (111) that are provided below the base portion (101) via driven links (121) and (122) on the left and right sides and are pivotable left and right relative to the base portion (101), and a gripping portion (114) is formed on the bracket portion (111). A suction pad (301) having a bellows structure that can be expanded and contracted in the vertical direction by a suction means and having an opening at its lower end;
a suction pad (301) that is movable up and down along with the suction pad (301) expanding and contracting, and has a top wall (202) that is larger than the opening diameter of a lower end opening (302) of the suction pad;
A link mechanism that is driven in accordance with the up and down movement of the attracted portion (201);
A pair of left and right gripping parts (114) are provided which perform opening and closing operations by the link mechanism,
The suction pad (301) has a lower end opening (302) pressed against the top wall portion (202) so as to be movable apart, and the lower end opening (302) is fixed to the top wall portion (202) by negative pressure generated during suction within the suction pad (301).
Article gripping device.

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