Clamping device

Abstract

To provide a clamping device having a simple structure and equipped with a device which prevents a conveyance object in a hanged state from falling.SOLUTION: A clamping device comprises: a pair of clamp arms which extends in the vertical direction and grips a conveyance object from both sides in the pair; an opening and closing drive device which drives so as to open and close the clamp arms; and a clamp arm support part which is provided above the clamp arms and supports the clamp arms via a lifting apparatus which elevates and lowers the clamp arms. Therein, the clamp arm has a grip part which is provided at a lower part of the clamp arm and grips the conveyance object from both sides, and an engaging part which is provided at an upper part of the clamp arm so as to face the clamp arm support part, and the clamp arm support part is provided with an engaged part which is engaged with the engaging part to restrict movement in a direction in which the grip part opens.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a clamping device provided with a fall prevention device for preventing a conveyed object held therein from falling.

Background Art

[0002] For example, in a casting line, an object such as a mold is clamped by a clamping device on a conveying path, lifted vertically, then laterally moved, and the mold is lowered vertically onto another conveying path. During that operation, there was a risk that the clamp of the clamping device would loosen and the conveyed object would fall during an emergency stop during lateral movement while the conveyed object was lifted, or during standby while the conveyed object was lifted. Therefore, in the frame alignment device of Patent Document 1, in order to prevent the lifted upper mold from falling, a fall prevention means (reference numeral 23 in Patent Document 1) is provided. This fall prevention means supports the lower end on the diagonal line of the upper mold placed on the receiving roller by a support member that rotates in a horizontal plane, thereby preventing the upper mold from falling during frame alignment.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the fall prevention means of Patent Document 1 has an extra rotating support means, which causes problems such as complication of the device and increase in equipment cost due to control for performing the rotating operation.

[0005] An object of the present invention is to provide a clamping device with a simple structure that prevents a conveyed object from falling in a suspended state.

Means for Solving the Problems

[0006] According to a first aspect of the present invention, a clamping device includes: clamping arms that extend in the vertical direction and grip a conveyed object from both sides in a pair; an opening and closing drive device that drives the clamping arms to open and close; and a clamping arm support portion that is provided above the clamping arms and is supported via a lifting device that raises and lowers the clamping arms.

[0007] The clamping arms have a gripping portion provided at a lower portion of the clamping arms for gripping the conveyed object from both sides, and a locking portion provided at an upper portion of the clamping arms so as to face the clamping arm support portion.

[0008] The clamping arm support portion includes a portion to be locked that, when the clamping arms rise when the gripping portion grips the conveyed object and closes, locks with the locking portion to restrict movement in a direction in which the gripping portion opens.

[0009] According to this, the locking portion and the portion to be locked restrict movement in a direction in which the gripping portion opens when the clamping arms rise while the gripping portion grips the conveyed object and closes. And it is possible to prevent the conveyed object gripped by the clamping arms from falling.

[0010] According to a second aspect of the present invention, the clamping arms include a rotation shaft that rotates the gripping portion provided at the lower portion so as to open and close.

[0011] According to this, the paired clamping arms can rotate about the rotation shaft to open and close the opposing gripping portions to grip the conveyed object.

[0012] According to a third aspect of the present invention, the clamping arms include a link member that connects above the rotation shaft of one of the clamping arms and below the rotation shaft of the other clamping arm to synchronize the opening and closing operations of the paired gripping portions.

[0013] According to this, the link member can synchronize the opening and closing operations of the paired gripping portions. According to a fourth aspect of the present invention, the opening and closing drive device is the opening and closing drive device connected to any one of the one and the other clamp arms.

[0014] According to this, the opening and closing drive device is a single opening and closing drive device that can drive both the one and the other clamp arms.

[0015] According to a fifth aspect of the present invention, each of the clamp arms is provided with a suppression device that suppresses the movement of the clamp arm in the opening direction in a state where the conveyed object is gripped and closed.

[0016] According to this, even when the driving force of the opening and closing drive device disappears, the suppression device suppresses the opening movement of the clamp arm, and it is possible to prevent the conveyed object from falling.

[0017] The locked portion is provided so as to project downward from the clamp arm support portion, and includes a contact surface that extends in the vertical direction and a locked portion inclined surface whose vertical protrusion height gradually decreases as it moves away from the top at the top of the lower end and is continuous with the contact surface. The locking portion is provided at the upper end portion of the clamp arm and includes a contact surface that extends in the vertical direction and contacts the contact surface, and a locking portion inclined surface whose vertical protrusion height gradually decreases as it moves away from the top of the upper end portion and is continuous with the contact surface at the top of the upper end portion.

[0018] According to this, even when the opening and closing width of the clamp arm is small, it is possible to reliably prevent the opening of the clamp arm by distinguishing between the closed state and the open state. Furthermore, since the gradually decreasing protruding portion that forms the locked portion inclined surface supports the locked portion contact surface from behind, the strength of the locked portion can be ensured.

[0019] According to a sixth aspect of the present invention, the clamp arm includes a linear guide mechanism that opens and closes the gripping portion by linearly moving the paired clamp arms in the horizontal direction.

[0020] According to this, the paired clamp arms can linearly move in the horizontal direction to open and close the opposing gripping portions to grip the conveyed object.

[0021] According to the seventh aspect of the present invention, the clamp arm support portion is a moving body that moves on a transfer path provided across a plurality of transfer paths for conveying the conveyed object.

[0022] According to this, the clamp arm support portion can move between a plurality of transfer paths and reliably transfer the conveyed object gripped by the clamp arm from one transfer path to another transfer path.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0024] (First Embodiment) The first embodiment in which the clamp device according to the present invention is implemented in the conveyance path of the casting line will be described below with reference to FIGS. 1 to 7.

[0025] FIG. 1 shows a part of the casting line and includes a clamp device 1, a first conveyance path TP1, a second conveyance path TP2, and a transfer path 4 according to the present invention. In this specification, the direction in which the casting frame or mold, which is the conveyed object T, is conveyed along the first and second conveyance paths TP2, TP2 is referred to as the "conveyance direction". Taking the conveyance of the casting frame or mold as an example of the flow of water, the side that is the starting point of conveyance in the casting line is referred to as the "upstream side", and the side that is the ending point of conveyance is referred to as the "downstream side". In the conveyance direction, the upstream direction is referred to as "rearward", and the downstream direction is referred to as "forward". When assuming a center line extending in the conveyance direction, the side farther from the center line is referred to as the "outer side", and the side closer to the center line is referred to as the "inner side".

[0026] (Clamp Device) The clamp device 1 grips the conveyed object T placed on the carriage on the first conveyance path TP1, lifts it in the gripped state, moves it to above the second conveyance path TP2, and lowers the conveyed object T gripped on the carriage FC on the second conveyance path TP2. The conveyed object T in this embodiment is, for example, a framed mold in which an upper mold with an upper casting frame and a lower mold with a lower casting frame are mated and molten metal is poured, and the mold before pouring and the mold after pouring are the objects. The upper casting frame is denoted by the symbol UF, and the lower casting frame is denoted by the symbol LF. Note that the conveyed object T is not limited to a framed mold, and may be, for example, a casting frame, a cast article placed on a pallet, or the like.

[0027] The clamping device 1 includes a lifting frame 11, a clamping arm 12, an opening / closing drive device 13, a lifting device 14, a clamping arm support portion 15, and a link member 16.

[0028] The lifting frame 11 includes, for example, an outer frame 11a made of iron and formed in a rectangular shape, and a horizontal support member (not shown) horizontally installed along the conveyance direction between two outer frames 11a and 11b facing each other in the conveyance direction (the upstream side and the downstream side). The clamping arm 12, the opening / closing drive device 13, and the lifting device 14 are attached to the lifting frame 11.

[0029] The clamping arm 12 is formed of, for example, an iron plate extending in the vertical direction, and includes a strip-shaped first clamping arm 121 and a second clamping arm 122 having a shorter length than the first clamping arm 121.

[0030] (The first clamping arm) The first clamping arm 121 is rotatably assembled to one end portion (the right end portion in FIG. 1) of the upstream outer frame 11a among the outer frames 11a facing the conveyance direction of the lifting frame 11 and the other end portion (the left end portion in FIG. 1, not shown) of the downstream outer frame 11b via rotation shafts 12a and 12b. The two first clamping arms 121 are provided to face each other on the diagonal line of the rectangular lifting frame 11 when viewed from above.

[0031] The rotation shaft 12a is rotatably supported by a bearing (not shown) provided on the lifting frame 11. The rotation shaft 12a of the first clamping arm 121 provided at one end portion of the upstream outer frame 11a shares the same rotation shaft 12a as the rotation shaft 12a of the second clamping arm 122 provided at one end portion of the downstream outer frame 11b. The first clamping arm 121 and the second clamping arm 122 are assembled to the rotation shaft 12a so as not to be relatively rotatable.

[0032] The rotating shaft 12a is provided with a suppression device 19 that suppresses the opening of the first clamp arm 121. The suppression device 19 is, for example, a coil spring that projects so as to maintain both ends at a predetermined angle with respect to the center of the coil, and is arranged around the rotating shaft 12a. One end of the coil spring is fixed to the clamp arm 12 and the other end is fixed to the lifting frame 11, respectively, and the first clamp arm 121 is biased to rotate in the closing direction.

[0033] A first gripping claw 121a (gripping portion) that projects in the inner lateral direction is provided at the lower end of the first clamp arm 121. The first gripping claw 121a is adapted to latch onto the lower side end of one side (right side in FIG. 1) of the lower casting frame LF which is the conveyed object T. It is adapted to grip the lower casting frame LF from both sides in cooperation with the second gripping claw 122a of the second clamp arm 122 described later.

[0034] (Locking portion) A locking portion 17 is formed at the upper end of the first clamp arm 121. The locking portion 17 has a contact surface 17a that extends in the vertical direction and contacts the contact surface 18a of the locked portion 18 described later, and a locking portion inclined surface 17b that is continuous with the contact surface 17a at the top of the upper end of the contact surface 17a.

[0035] The locking portion inclined surface 17b is formed such that the protruding height (protrusion amount) in the vertical direction gradually decreases as it moves away from the top of the upper end. In this way, the locking portion 17 is formed into an acute angle with the top as the tip by the contact surface 17a extending in the vertical direction and the locking portion inclined surface 17b. The locking portion inclined surface 17b is configured to be parallel to the locked portion inclined surface 18b described later.

[0036] The central portion between the upper end and the lower end of the first clamp arm 121 is pivotally supported by the lifting frame 11 by the rotating shaft 12a so as to be rotatable. The tip of the piston rod 132 of the opening and closing drive device 13 described later is connected via a connecting shaft 132a to a position at the upper one-third between the upper end of the first clamp arm 121 and the rotating shaft 12a.

[0037] (Opening and Closing Driving Device) The opening and closing driving device 13 includes a cylinder part 131 and a piston rod 132. The cylinder part 131 is assembled to the upstream outer frame 11a of the two outer frames 11a facing the conveying direction of the lifting frame 11 via a bracket 133. The cylinder part 131 is provided so as to extend in the horizontal direction perpendicular to the conveying direction. The cap side of the cylinder part 131 is connected to the bracket 133 via a connecting shaft 131a extending along the conveying direction. The cylinder part 131 communicates with a hydraulic pump (not shown) via an oil supply pipe (not shown).

[0038] An electromagnetic switching valve (not shown) is provided between the cylinder part 131 and the hydraulic pump. The switching operation of the electromagnetic switching valve is controlled by a control device (not shown). The piston rod 132 is provided with a piston that slides on the inner wall of the cylinder part 131 at the base end, and the tip end side advances and retreats in the horizontal direction perpendicular to the conveying direction from the opening side of the cylinder part 131. The tip end of the piston rod 132 is connected to a position on the upper end side above the rotation shaft 12a of the first clamp arm 121. Therefore, the first clamp arm 121 closes when the piston rod 132 advances and opens when the piston rod 132 retreats.

[0039] One end of a link member 16 is connected between the rotation shaft 12a of the first clamp arm 121 and the connecting shaft 132a of the piston rod 132 via a connecting shaft 16a. The other end of the link member 16 is connected to a second clamp arm 122 described later.

[0040] (Second Clamp Arm) The second clamp arm 122 has an upper end pivotally supported on a rotation shaft 12b so as to be rotatable, and a second gripping claw 122a (gripping portion) is formed at the lower end. A suppression device 19 similar to that of the first clamp arm 121 is also provided on the rotation shaft 12b of the second clamp arm 122. The second gripping claw 122a is formed to project inwardly facing the first gripping claw 121a of the first clamp arm 121. The other end of the link member 16 is connected via a connecting shaft 16b at a position below the rotation shaft 12b and in the upper quarter between the upper end and the lower end of the second clamp arm 122.

[0041] (Link member) The link member is formed, for example, of iron and in a rod shape. By connecting the portion above the rotation shaft 12a of the first clamp arm 121 and the portion below the rotation shaft 12b of the second clamp arm 122 with the link member 16, for example, when the first clamp arm 121 performs a closing operation, the lower portion of the second clamp arm 122 below the rotation shaft 12b is pulled inwardly to perform a closing operation. When the first clamp arm 121 performs an opening operation, the lower portion of the second clamp arm 122 below the rotation shaft 12b is pushed outwardly to perform an opening operation. In this way, the opening and closing operations of the first clamp arm 121 and the second clamp arm 122 are synchronized by the link member 16.

[0042] As shown in FIG. 2, the rotation shaft 12a of the first clamp arm 121 attached to the upstream outer frame 11a and the rotation shaft 12a of the second clamp arm 122 attached to the downstream outer frame 11b share the same rotation shaft 12a. Therefore, rotational torque is transmitted from the first clamp arm 121 on the upstream side to the second clamp arm 122 on the downstream side. Also, rotational torque is similarly transmitted between the second clamp arm 122 of the upstream outer frame 11a and the first clamp arm 121 of the downstream outer frame 11b via the rotation shaft 12b.

[0043] The second clamp arm 122 attached to the downstream outer frame 11b and the first clamp arm 121 attached to the downstream outer frame 11b are connected by a link member 16 in the same manner as the first clamp arm 121 and the second clamp arm 122 of the upstream outer frame 11a. Therefore, the opening and closing operations of the four clamp arms 12 are synchronously executed by one opening and closing drive device 13 provided on the upstream side.

[0044] (Lifting device) The lifting device 14 is provided between the clamp arm support portion 15 and the lifting frame 11, and moves the lifting frame 11 and the clamp arms 12 in the vertical direction. As shown in FIG. 2, the lifting device 14 includes a lifting cylinder device 141 and a vertical guide device 142. The lifting cylinder device 141 includes a lifting cylinder portion 141a and a lifting piston rod 141b.

[0045] The lifting cylinder portion 141a is provided so as to extend in the vertical direction, and the lower portion of the lifting cylinder portion 141a is assembled so as to penetrate the clamp arm support portion 15. The lifting piston rod 141b is provided on the lower end side of the lifting cylinder portion 141a so as to advance and retract downward. The lower end portion of the lifting piston rod 141b is assembled to the central portion of the lifting frame 11, for example, by screwing. The lifting cylinder portion 141a communicates with a hydraulic pump (not shown) via an oil supply pipe (not shown). An electromagnetic switching valve (not shown) is provided between the lifting cylinder portion 141a and the hydraulic pump. The operation of the electromagnetic switching valve is controlled by a control device (not shown).

[0046] The vertical guide device 142 guides the vertical movement of the lifting frame 11 in the vertical direction. The vertical guide device 142 is provided on both sides along the conveyance direction of the lifting cylinder device 141, and includes a guide cylinder 142a and a guide rod 142b respectively. Each guide cylinder 142a is formed in a cylindrical shape. Each guide cylinder 142a is assembled so that its upper part penetrates through the clamp arm support part 15. The guide rod 142b is slidably inserted into the guide cylinder 142a respectively, and the lower end part is assembled to the lifting frame 11 by fastening with, for example, a screw.

[0047] (Clamp arm support part) The clamp arm support part 15 (moving body) supports the clamp arm 12 and moves on the transfer rail 41 of the transfer path 4 described later. As shown in FIG. 1, the clamp arm support part 15 includes a transfer cart 151, a transfer cart drive device 152, and a locked part 18. The clamp arm support part 15 supports the lifting frame 11 and the clamp arm 12 provided below via the aforementioned lifting device 14 so as to suspend them.

[0048] The transfer cart 151 is made of, for example, iron and is formed in a rectangular plate shape. Rolling wheels 151a having rotating shafts extending in the conveyance direction are provided at the four corners of the transfer cart 151 respectively. The rolling wheels 151a roll on the transfer rail 41 of the transfer path 4 described later. An electric motor 152a of the transfer cart drive device 152 is assembled at a position on the upper surface of the transfer cart 151 on the second transfer path TP2 side of the upstream side.

[0049] (Transfer cart drive device) The transfer cart drive device 152 includes an electric motor 152a, a drive sprocket 152b, a driven sprocket 152c, and a roller chain 152d. The electric motor 152a has an output shaft extending in a direction along the transport direction of the first transport path TP1, and the drive sprocket 152b is non-rotatably assembled to the output shaft. The drive sprocket 152b is provided to face a rolling wheel 151a located on the second transport path TP2 side upstream of the transfer cart among the rolling wheels 151a.

[0050] The driven sprocket 152c is non-rotatably provided on the rotation shaft of this rolling wheel 151a. A roller chain 152d is mounted between the drive sprocket 152b and the driven sprocket 152c. When the output shaft of the electric motor 152a rotates, the rotational torque is transmitted through the drive sprocket 152b, the roller chain 152d, and the driven sprocket 152c to rotationally drive the rolling wheel 151a. Thereby, by rotating the electric motor 152a forward and backward, the transfer cart 151 is moved along the transfer rail 41. The operation of the rotation of the electric motor 152a is controlled by a control device (not shown).

[0051] (Locked portion) The locked portion 18 is provided at the bottom surface of the transfer cart 151 at a position facing the locking portion 17 of the first clamp arm 121. The locked portion 18 has a contact surface 18a that extends in the vertical direction and contacts the contact surface 17a of the locking portion 17, and a locked portion inclined surface 18b that is continuous with the contact surface 18a at the top of the lower end portion of the contact surface 18a. The locked portion inclined surface 18b is formed such that the protruding height (protrusion amount) in the vertical direction gradually decreases as it moves away from the top of the lower end portion.

[0052] The engaging portion inclined surface 17b and the engaged portion inclined surface 18b are formed to be parallel. As a result, when the first clamp arm 121 rises to the ascending end position while being opened at a small angle, as shown in FIG. 1, the contact between the engaging portion 17 and the engaged portion 18 is prevented. By preventing the contact between the engaging portion 17 and the engaged portion 18 in this way, even when the first clamp arm 121 is positioned at the ascending end while being opened at a small angle, force is not transmitted between them, that is, in other words, by contact, it does not hinder the smooth opening / closing and ascending / descending operations of the clamp arm 12.

[0053] (First Conveyor Path · Second Conveyor Path) The first conveyor path TP1 conveys the carriage FC on which the conveyed object T (framed mold) is placed. The first conveyor path TP1 includes a gantry ST installed on the floor surface BG and a pair of conveyor rails TR provided on the gantry ST so as to extend along the conveying direction. Since the first conveyor path TP1 is a known technique, the description thereof is omitted. The second conveyor path TP2 has the same configuration as the first conveyor path TP1, but is different in that the conveying direction of the carriage FC on which the conveyed object T is placed is opposite to the conveying direction of the first conveyor path TP1. Since it is also a known technique, the description thereof is omitted.

[0054] A plurality of carriages FC on which the conveyed object T is placed are arranged in a row on the conveyor rail TR. The carriage FC is provided with rolling wheels, and can move on the conveyor rail TR by the rolling of the rolling wheels. Then, the plurality of carriages FC move by a pusher device and a cushion device (not shown). The first pusher device (not shown) is provided at the upstream end of the first conveyor path TP1, and presses the rearmost carriage FC arranged on the first conveyor path TP1 by one stroke (the length in the conveying direction of one carriage FC) in the conveying direction.

[0055] The first cushion device (not shown) is provided at the downstream end of the first transfer path TP1 and functions to receive the foremost trolley FC among the trolleys FC arranged on the first transfer path TP1. In the first mold transfer device MT1, a plurality of trolleys FC are transferred in the transfer direction one stroke at a time while being sandwiched between the first cushion device and the first pusher device so as not to move freely. Since the first pusher device and the first cushion device are well-known technologies, detailed descriptions thereof are omitted.

[0056] (Transfer path) The transfer path 4 is provided across the first transfer path TP1 and the second transfer path TP2. It includes a transfer rail 41 provided above and orthogonal to the first transfer path TP1 and the second transfer path TP2, a rail support member 42 that supports the transfer rail 41, and a support column 43 that supports the end of the rail support member 42. The transfer rails 41 are provided parallel to each other so as to extend in the horizontal direction. On the transfer rails 41, the rolling wheels 151a of the clamp arm support portion 15 as a moving body roll.

[0057] Each transfer rail 41 is supported by a rail support member 42 extending along the transfer rail 41. The rail support member 42 is formed of, for example, an iron member having a rectangular cross-section. Both ends of each rail support member 42 are supported by the support columns 43 respectively. The lower end of each support column 43 is installed on the floor surface BG and the upper end is connected to the rail support member 42. A stopper bolt SB is attached to the end of the rail support member 42 to prevent the clamp arm support portion 15 from stopping at the end of the transfer rail 41 and falling off the transfer rail 41. Position sensors PS are arranged at both ends of the transfer rail 41 to detect the movement of the clamp arm support portion 15 to the end and transmit a detection signal to the control device.

[0058] The clamp arm support portion 15 can move above the first transfer path TP1 and above the second transfer path TP2 by the transfer path 4 formed in this way, and can transfer the conveyed object T (framed mold) gripped by the clamping device 1 from the first transfer path TP1 to the second transfer path TP2.

[0059] (Control device) The control device controls the operation of the cylinder portion 131 of the opening and closing drive device 13, the lifting cylinder device 141 of the lifting device 14, the electric motor 152a of the transfer cart drive device 152, the first pusher device, the second pusher device, the first cushion device, and the second cushion device.

[0060] (Operation) Next, the operation of the clamping device 1 configured as described above will be described below with reference to FIGS. 1 to 8. As shown in FIGS. 1 and 2, the clamp arm support portion 15 is positioned above the first transfer path TP1. The clamp arm 12 is in an open state, and the lifting frame 11 is positioned at the upper end. In this case, the locking portion inclined surface 17b of the locking portion 17 and the locked portion inclined surface 18b of the locked portion 18 face each other with a gap therebetween, and the locking portion 17 and the locked portion 18 are not in contact (see FIG. 7).

[0061] Below the clamping device 1, a conveyed object T (a framed mold in which the upper casting frame UF and the lower casting frame LF are overlapped) that has been conveyed on the first transfer path TP1 is positioned.

[0062] As shown in FIG. 3, the control device drives the lifting cylinder device 141 to lower the lifting frame 11, and then drives the opening and closing drive device 13 to close the clamp arm 12. At that time, the gripping claws 121a, 122a of the clamp arm latch the outer lower end of the lower casting frame LF.

[0063] Next, as shown in FIG. 4, the control device drives the lifting cylinder device 141 to raise the lifting frame 11 to the upper end. At this time, the contact surface 17a of the locking portion 17 and the contact surface 18a of the locked portion 18 come into contact with each other, and the closed state of the clamp arm 12 is surely ensured (see FIG. 8).

[0064] Next, as shown in FIG. 5, the control device drives the electric motor 152a of the transfer cart drive device 152 to rotate the rolling wheel 151a, and moves the clamp arm support portion 15 (transfer cart 151) above the second transfer path TP2. The stop position is detected by the position sensor PS, and a detection signal is transmitted to the control device. The control device stops the drive of the electric motor 152a based on the detection signal, gradually reduces the moving speed of the transfer cart 151, and surely stops the transfer cart 151 with the stopper bolt SB.

[0065] Next, the control device drives the lifting cylinder device 141 to lower the lifting frame 11. The control device stops the lowering when the lower end of the conveyed object T comes into contact with the upper surface of the cart FC placed on the second transfer path TP2. The contact between the cart FC and the conveyed object T is detected by a position sensor (not shown).

[0066] Next, the control device drives the opening / closing drive device 13 to open the clamp arm 12 and transfer the conveyed object T to the cart FC. Next, the control device returns the clamp arm 12 that is not holding anything above the first transfer path TP1 and performs the same operations hereinafter.

[0067] As is clear from the above description, the clamp device 1 of the present embodiment includes clamp arms 12 that extend in the vertical direction and grip the conveyed object T from both sides in pairs, an opening / closing drive device 13 that drives the clamp arms 12 to open and close, and a clamp arm support portion 15 that is provided above the clamp arms 12 and is supported via a lifting device 14 that raises and lowers the clamp arms 12.

[0068] The clamp arm 12 has a first gripping claw 121a and a second gripping claw 122a provided at the lower part of the clamp arm 12 for gripping the conveyed object T from both sides, and a locking portion 17 provided at the upper part of the clamp arm 12 so as to face the clamp arm support portion 15.

[0069] The clamp arm support portion 15 is provided with a locked portion 18 that, when the clamp arm 12 rises with the first gripping claw 121a and the second gripping claw 122a gripping the conveyed object T in a closed state, locks with the locking portion 17 to restrict the movement of the first gripping claw 121a and the second gripping claw 122a in the opening direction.

[0070] According to this, when the clamp arm 12 rises with the first gripping claw 121a and the second gripping claw 122a gripping the conveyed object T in a closed state, the locking portion 17 and the locked portion 18 restrict the movement of the first gripping claw 121a and the second gripping claw 122a in the opening direction. And it is possible to prevent the conveyed object T gripped by the clamp arm 12 from falling.

[0071] The first clamp arm 121 and the second clamp arm 122 are provided with rotating shafts 12a and 12b for rotating the first gripping claw 121a and the second gripping claw 122a provided at the lower part so as to open and close.

[0072] According to this, the paired first clamp arm 121 and second clamp arm 122 can rotate about the rotating shafts 12a and 12b to open and close the opposing first gripping claw 121a and second gripping claw 122a to grip the conveyed object T.

[0073] The first clamp arm 121 and the second clamp arm 122 are provided with a link member 16 that connects above the rotating shaft 12a of one first clamp arm 121 and below the rotating shaft 12b of the other second clamp arm 122 to synchronize the opening and closing operations of the paired first gripping claw 121a and second gripping claw 122a.

[0074] According to this, the link member 16 can synchronize the opening and closing operations of the paired first gripping claws 121a and second gripping claws 122a.

[0075] In addition, the opening and closing drive device 13 is an opening and closing drive device 13 connected to any one of the first clamp arm 121 and the second clamp arm 122 of the clamp arms 12.

[0076] According to this, the opening and closing drive device 13 is a single opening and closing drive device 13 that can drive any of the clamp arms 12 of the first clamp arm 121 and the second clamp arm 122.

[0077] In addition, each clamp arm 12 is provided with a suppression device 19 that suppresses the movement of the clamp arm 12 in the opening direction in a state where the conveyed object T is gripped and closed. The suppression device 19 is, for example, a coil spring with both ends protruding at a predetermined angle with respect to the center of the coil, arranged around the rotation shafts 12a and 12b. One end is fixed to the clamp arm 12 and the other end is fixed to the lifting frame 11, and the clamp arm 12 is urged to rotate in the closing direction.

[0078] According to this, even when the driving force of the opening and closing drive device 13 disappears, the suppression device 19 suppresses the opening movement of the first gripping claws 121a and the second gripping claws 122a of the clamp arm 12, and it is possible to prevent the conveyed object T from falling.

[0079] In addition, the locked portion 18 is provided so as to protrude downward from the clamp arm support portion 15, and includes a contact surface 18a extending in the vertical direction and a locked portion inclined surface 18b whose vertical protrusion height gradually decreases as it extends away from the top at the top of the lower end and is continuous with the contact surface 18a.

[0080] The locking portion 17 is provided at the upper end of the clamp arm 12, and includes a contact surface 17a that extends in the vertical direction and contacts the surface to be contacted 18a, and a locking portion inclined surface 17b that is continuous with the contact surface 17a at the top of the upper end and whose protruding height in the vertical direction gradually decreases as it moves away from the top of the upper end.

[0081] When the clamp arm 12 ascends in a state where the first gripping claw 121a and the second gripping claw 122a grip and close the conveyed object T, the contact surface 17a and the surface to be contacted 18a can come into contact. When the clamp arm 12 ascends in a state where the first gripping claw 121a and the second gripping claw 122a are open, the locking portion inclined surface 17b and the locked portion inclined surface 18b face each other without transmitting force to each other.

[0082] According to this, even when the opening and closing width of the clamp arm 12 is small, when the clamp arm 12 is open, there is no interference between the locking portion 17 and the locked portion 18. Therefore, it is possible to distinguish between the closed state and the open state of the first gripping claw 121a and the second gripping claw 122a, and reliably and smoothly prevent the clamp arm from opening. Furthermore, since the gradually decreasing protruding portion forming the locked portion inclined surface 18b supports the surface to be contacted 18a of the locked portion from behind, the strength of the locked portion 18 can be ensured.

[0083] The clamp arm support portion 15 is a moving body that moves on a transfer path 4 provided across a plurality of transfer paths TP1, TP2 for conveying the conveyed object T.

[0084] According to this, the clamp arm support portion 15 can move between a plurality of transfer paths TP1, TP2, and reliably transfer the conveyed object T gripped by the clamp arm 12 from one transfer path TP1 to another transfer path TP2.

[0085] (Second Embodiment) Next, a second embodiment of the clamp device according to the present invention will be described below with reference to FIGS. 9 and 10. The clamping device 21 of the second embodiment does not rotate around a rotating shaft to open and close the clamping arm. Instead, it linearly moves two opposing clamping arms 22 in the horizontal direction to open and close the gripping part (gripping claws 22a) of the clamping arm 22, which is different from the clamping device 1 of the first embodiment. Hereinafter, the differences will be mainly described in detail.

[0086] The lifting frame 211 is made of, for example, iron and is formed in a rectangular plate shape. The lifting frame 211 is provided with four horizontal guide rods 292 protruding so as to extend in the horizontal direction and is lifted by a lifting device (not shown). The horizontal guide rods 292 are made of, for example, iron and are formed in a rod shape with a circular cross-section, and are fastened to the side portion of the lifting frame 211 at the base end portion, for example, by screws.

[0087] The clamping arm 22 is provided with a horizontal guide cylinder 291 integrally provided at the upper part. The horizontal guide cylinder 291 is slidably externally fitted to the horizontal guide rod 292. A stopper 293 is provided at the tip of the horizontal guide rod by bolts to prevent the horizontal guide cylinder 291 from coming out of the horizontal guide rod 292. The horizontal guide cylinder 291 and the horizontal guide rod 292 constitute a linear guide mechanism 29.

[0088] An opening / closing drive device 23 is provided between the clamping arms 22 that are paired at the upper part of the clamping arm 22. The opening / closing drive device 23 includes an oil hydraulic cylinder device 231 and a piston rod 232, and is provided so as to extend along the horizontal direction parallel to the horizontal guide rod 292 and the horizontal guide cylinder 291. A locking portion 27 is provided at the upper end portion of the clamping arm 22. A gripping claw 22a is provided at the lower end portion of the clamping arm 22.

[0089] On the lower surface of the clamp arm support portion 25, a locked portion 28 is provided so as to face the locking portion 27 of the clamp arm 22. The contact surface 27a of the locking portion 27 is on the outside, and the locking portion inclined surface 27b is on the inside, which is the reverse of the first embodiment. Regarding the locked portion 28 as well, the contact surface 28a is on the inside and the locked portion inclined surface 28b is on the outside.

[0090] As is clear from the above description, in the clamp device 21 of the second embodiment, the clamp arm 22 includes a direct-acting guide mechanism 29 that opens and closes the gripping claws 22a by the paired clamp arms 22 linearly moving in the horizontal direction.

[0091] According to this, the paired clamp arms 22 can linearly move in the horizontal direction to open and close the opposing gripping claws 22a and grip the conveyed object T.

[0092] Note that the gripping portion of the clamp arm 12 is not limited to the gripping claws (first gripping claw 121a, second gripping claw 122a). Any device that can grip the conveyed object is acceptable, and it can be appropriately changed according to the shape and type of the conveyed object.

[0093] Also, the suppression device 19 is not limited to arranging a coil spring with both ends protruding at a predetermined angle around the rotation axis. For example, a coil spring may be provided between the opposing clamp arms to bias the clamp arms in the closing direction.

[0094] Note that the locking portion 17 and the locked portion 18 are not limited to locking protruding members to each other. For example, a protrusion (locking portion) may be locked to a hole (locked portion) formed on the lower surface of the clamp arm support portion.

[0095] The present invention is not limited only to the embodiments described above and shown in the drawings, and can be appropriately changed and implemented without departing from the gist.

Explanation of Reference Numerals

[0096] 1: Clamping device, 11: Lifting frame, 12: Clamping arm, 121: First clamping arm, 122: Second clamping arm, 12a: Rotation axis, 12b: Rotation axis, 121a: First gripping claw (gripping part), 122a: Second gripping claw (gripping part), 13: Opening and closing drive device, 14: Lifting device, 15: Clamping arm support part, 151: Transfer cart (moving body), 16: Link member, 17: Locking part, 17a: Contact surface, 17b: Locking part inclined surface, 18: Locked part, 18a: Locked part contact surface, 18b: Locked part inclined surface, 21: Clamping device, 22: Clamping arm, 23: Opening and closing drive device, 25: Clamping arm support part (moving body), 27: Locking part, 28: Locked part, 29: Straight - advancing guide mechanism, 291: Horizontal guide cylinder, 292: Horizontal guide rod, 4: Transfer path, T: Conveyed object, TP1: First transfer path (transfer path), TP2: Second transfer path (transfer path).

Claims

1. A clamp device comprising: clamp arms extending in the vertical direction and gripping a conveyed object from both sides; an opening / closing drive device for driving the clamp arms to open and close; a clamp arm support portion provided above the clamp arms and supported via a lifting device for lifting and lowering the clamp arms; wherein the clamp arm has a gripping portion provided at the lower part of the clamp arm for gripping the conveyed object from both sides and a locking portion provided at the upper part of the clamp arm so as to face the clamp arm support portion; the clamp arm support portion has a locked portion that can come into contact with the locking portion when the clamp arm rises in a state where the gripping portion grips the conveyed object and closes, and restricts the movement of the gripping portion in the opening direction, and the locked portion does not come into contact with the locking portion when it rises in a state where the gripping portion is open; when the clamp arm descends in a state where the gripping portion grips the conveyed object and closes, the locking portion separates from the contact with the locked portion, and the clamp device releases the restriction on the opening direction of the gripping portion.

2. The clamp device according to claim 1, wherein the clamp arm includes a rotating shaft for rotating the gripping portion provided at the lower part so as to open and close.

3. The clamp device according to claim 2, wherein the clamp arm includes a link member for synchronizing the opening and closing operations of the paired gripping portions by connecting above the rotating shaft of one of the clamp arms and below the rotating shaft of the other clamp arm.

4. The clamp device according to claim 3, wherein the opening / closing drive device is an opening / closing drive device connected to any one of the one and the other clamp arms.

5. The clamp device according to any one of claims 1 to 4, wherein each clamp arm is provided with a suppressing device for suppressing the movement of the clamp arm in the opening direction in a state where the conveyed object is gripped and closed.

6. The clamp device according to claim 1, wherein the clamp arm includes a linear guide mechanism for opening and closing the gripping portion by linearly moving the paired clamp arms in the horizontal direction.

7. ​ The locked portion is provided so as to protrude downward from the clamp arm support portion, and includes a contact surface that extends in the vertical direction and a locked portion inclined surface whose downward protrusion amount gradually decreases as it moves away from the top at the top of the lower end and is continuous with the contact surface. The locking portion is provided at the upper end of the clamp arm, and includes a contact surface that extends in the vertical direction and contacts the contact surface, and a locking portion inclined surface whose upward protrusion amount gradually decreases as it moves away from the top of the upper end and is continuous with the contact surface at the top of the upper end. When the clamp arm rises in a state where the gripping portion grips and closes the conveyed object, the contact surface and the contact surface to be contacted can come into contact with each other. The clamp device according to any one of claims 1 to 6, wherein when the clamp arm rises in a state where the gripping portion is open, the locking portion inclined surface and the locked portion inclined surface face each other without transmitting force to each other.

8. The clamp device according to any one of claims 1 to 7, wherein the clamp arm support portion is a moving body that moves on a transfer path provided across a plurality of transfer paths for conveying the conveyed object.

Images