WO2008050430A1

WO2008050430A1 - Clamp device

Info

Publication number: WO2008050430A1
Application number: PCT/JP2006/321391
Authority: WO
Inventors: Ichiro Kitaura
Original assignee: Pascal Engineering Corporation
Priority date: 2006-10-26
Filing date: 2006-10-26
Publication date: 2008-05-02

Abstract

A clamp device that has a smoothly operating synchronous movement mechanism, that is constructed with desired strength to increase its durability, where a pair of clamp members is reliably synchronously moved in a manner symmetrical with respect to a standard clamp position, and where a workpiece is reliably positioned and clamped at the standard clamp position. In the synchronous movement mechanism (8), base ends of a pair of rod members (70) are connected to a pair of clamp members (3), tubular rotating members (71) are fitted on the forward ends of the pair of rod members (70), a pair of three-thread screw grooves (72) whose threads are formed in opposite directions each other, the tubular rotating members (71) are supported by a base member (2) so as to be rotatable about the axis of the rod members (70), two sets of ball members (73) are rotatably held by the tubular rotating members (71) such that the ball members are projected to the axis side from the inner peripheral surface of the tubular rotating members (72), and the two sets of ball members (73) engage with the pair of three-thread screw grooves (72).

Description

Specification

Clamping device

Technical field

The present invention relates to a clamp device provided with a synchronous movement mechanism that synchronously moves a pair of clamp members symmetrically with respect to a clamp reference position.

Background art

[0002] Conventionally, as a device for fixing a workpiece when various processing is performed on the workpiece by a machine tool, a base member and a pair of clamping members opposed to each other for clamping the workpiece from both sides above the base member A guide mechanism that guides a pair of clamp members so that the pair of clamp members moves and moves in a direction that approaches and separates.

A clamping device having a clamp driving mechanism for driving in a separation direction is well known.

[0003] As a clamp device of this type, a pair of clamp members driven by a clamp drive mechanism are clamped in a close and separate direction in order to clamp a workpiece at a predetermined clamp reference position by a pair of clamp members. Clamp devices equipped with various synchronous moving mechanisms that move synchronously symmetrically with respect to a position have been put to practical use (see, for example, Patent Documents 1 to 3).

[0004] In the clamp device of Patent Document 1, the clamp drive mechanism includes a screw shaft disposed parallel to the approaching / separating direction of the pair of clamp members, a motor for rotating the screw shaft, and a pair of clamp members. It has a pair of nuts fixed to the lower end and screwed onto the screw shaft, and this clamp drive mechanism has a screw nut mechanism that functions as a synchronous movement mechanism. The screw groove of the screw shaft into which one nut is screwed and the screw groove of the screw shaft into which the other nut is screwed are formed in mutually opposite threads.

[0005] In the clamp device of Patent Document 2, the clamp drive mechanism has a pair of fluid pressure cylinders that drive the pair of clamp members in the approach and separation directions, respectively. The clamp member is fixed to the cylinder body of the fluid pressure cylinder, and the rod of the fluid pressure cylinder is connected to the base member. Synchronous movement mechanism force S Rack and pinion mechanism force is also provided, and this rack and pinion mechanism has a pinion rotatably supported by a base member and a pair of racks respectively connected to a pair of clamp members. The rack is combined with the pion! / [0006] In the clamp device of Patent Document 3, the clamp drive mechanism has a fluid pressure cylinder that drives one of the clamp members, transmits the driving force of the clamp drive mechanism to the other clamp member, and serves as a synchronous movement mechanism. A functioning link mechanism is provided. This link mechanism has a disc-shaped cam that is rotatably supported by a base member, and a pair of levers each having one end rotatably connected to a pair of clamp members. The other end of the is rotatably connected to the force. Patent Document 3 discloses a mode in which a motor is used instead of a fluid pressure cylinder, and a mode in which a rack pion mechanism similar to Patent Document 2 is used instead of a link mechanism.

Patent Document 1: Japanese Patent Laid-Open No. 6-31564

Patent Document 2: JP-A-60-244497

Patent Document 3: Japanese Patent Laid-Open No. 2000-84769

Disclosure of the invention

Problems to be solved by the invention

Conventionally, in a clamping device, a strong clamping force that clamps a workpiece from both sides by a pair of clamping members, that is, a powerful clamping driving force that drives a pair of clamping members in an approaching direction by a clamp driving mechanism. In this case, a very large load is applied to the synchronous movement mechanism in the clamp device having the synchronous movement mechanism that synchronously moves the pair of clamp members symmetrically with respect to the clamp reference position. .

[0009] In the screw nut mechanism of Patent Document 1, the nut is simply screwed onto the screw shaft, and a strong clamp driving force is output. In this case, the screw shaft is driven to rotate by a motor, Since the drive force is transmitted from the screw shaft to a pair of clamp members, it is necessary to reduce the lead angle of the thread groove.As a result, the friction acting between the screw shaft and the nut increases, It may not work smoothly, and is weak in strength and has a problem with durability.

[0010] In the rack pion mechanism of Patent Document 2, a very large load acts on the rack pion mechanism, so that it is also weak in strength and has a problem in durability. The link mechanism of Patent Document 3 is still weak in strength and has a problem with durability, and when the movement stroke of a pair of clamp members is increased, the cam needs to be enlarged two-dimensionally, so it is compact. Ni It may not be possible.

[0011] In addition, in the clamp device of Patent Document 1, the pair of clamp members is guided by a guide mechanism so that the lower end portions of the clamp members are movable, and a clamp driving force is input from the lower end portions. In the clamping device of Patent Document 3, the other clamping member that is not directly driven by the fluid pressure cylinder is used to clamp the workpiece when clamping the workpiece. There is a risk of rattling.

[0012] In the clamp device of Patent Document 2, the clamp drive mechanism has a pair of fluid pressure cylinders that directly drive a pair of clamp members in the approaching and separating directions, respectively. Compared to a device, there is less risk of rattling when a pair of clamp members clamps a workpiece, but when the clamp members are large in size up and down, a large moment acts on the clamp members by the workpiece, and the clamp members There is a risk of rattling. If the clamp member is rattled in this way, the workpiece may be reliably positioned at the clamp reference position and may not be clamped.

[0013] An object of the present invention is to form a synchronous movement mechanism that operates smoothly in a clamp device, to increase the durability by configuring the synchronous movement mechanism to have a desired high strength, and a pair of clamp members For example, to ensure that the workpiece is synchronously moved symmetrically with respect to the clamp reference position, and that the workpiece is reliably positioned and clamped at the clamp reference position.

Means for solving the problem

[0014] The clamping device according to claim 1 is a base member, and a pair of opposing clamping members for clamping a workpiece from a both sides to a predetermined clamping reference position above the base surface of the base member, A clamp having a guide mechanism for guiding a pair of clamp members so that the clamp members can move in the approaching / separating direction and a clamp driving mechanism for driving the pair of clamping members in the approaching / separating direction. The apparatus is provided with a synchronous moving mechanism that synchronously moves a pair of clamp members driven by the clamp driving mechanism in the approaching / separating direction symmetrically with respect to the clamp reference position, and the synchronous moving mechanism is A pair of rod members disposed so as to be parallel to the approaching / separating direction and having the same axial center, the distal ends of the rod members being opposed to each other and the proximal end portion being a pair of clamping members Are connected to each other and built into the base member so that they can move toward and away from each other and cannot rotate. A pair of rod members respectively supported by the cylindrical member, and a cylindrical rotating member that is externally fitted to the tip side portion of the pair of rod members and is supported by the base member so as to be rotatable about the axis of the rod member; A pair of one or a plurality of screw grooves formed on the tip side portion of the pair of rod members, respectively, and a pair of one or a plurality of screw grooves formed in reverse threads with each other; Two sets of engagements that are held by the cylindrical rotating member so as to protrude axially from the inner peripheral surface of the cylindrical rotating member and are engaged with the pair of one or more screw grooves, respectively. And a joint member.

[0015] In this clamp device, the pair of clamp members are driven toward and away by the clamp drive mechanism, and the pair of clamp members driven by the clamp drive mechanism are approached by the synchronous movement mechanism. It is synchronously moved symmetrically with respect to the clamp reference position in the separation direction. A pair of clamp members are separated by a clamp drive mechanism and a synchronous movement mechanism in a state where the pair of clamp members are separated from each other by a distance larger than the width of the clamped portion of the workpiece and the workpiece is disposed between the pair of clamp members. Is driven in the approaching direction and moved synchronously, and the workpiece is positioned and clamped at the clamp reference position by a pair of clamp members.

[0016] Various actuators such as a hydraulic cylinder, a hydraulic motor, and an electric motor can be used as the actuator of the clamp drive mechanism. A high output power is desirable. Also, the rod member is linearly driven together with the clamp member. Therefore, a hydraulic cylinder is preferable. Further, a pair of actuators for driving a pair of clamp members or a pair of rod members may be provided. Alternatively, one actuator that drives only one clamp member or one rod member may be provided. In this case, the clamp moving force is transmitted to one rod member force and the other rod member by the synchronous movement mechanism, and the pair of clamp members are moved synchronously.

[0017] In the synchronous movement mechanism, a pair of rod members are arranged so as to be parallel to the approaching / separating direction of the pair of clamp members and in such a manner that the shaft centers coincide with each other, and the tips of these rod members are opposed to each other. The base end portions are respectively connected to a pair of clamp members, and are incorporated in the base member so as to be movable toward and away from each other and non-rotatably supported. A cylindrical rotating member is externally fitted to the tip side portion of the pair of rod members, and a pair of one or a plurality of screw grooves are formed on the tip side portions of the pair of rod members as mutually reverse screws. Cylindrical rotating member Is supported by the base member so as to be rotatable about the axis of the rod member, and two sets of engaging members are held on the cylindrical rotating member so as to protrude from the inner peripheral surface of the cylindrical rotating member toward the axial center. Two sets of engaging members are engaged with a pair of one or more screw grooves.

[0018] When the pair of rod members move toward and away from each other, the cylindrical rotating member rotates through one or more screw grooves and the engaging member. Alternatively, a plurality of screw grooves and two sets of engaging members cause a pair of rod members to move synchronously in the approaching / separating direction, so a pair of clamp members connected to a pair of rod members Approach • Moves symmetrically with respect to the clamp reference position in the separation direction.

Here, the following various configurations may be employed in the present invention.

(a) The two sets of engaging members are rotatably held by the cylindrical rotating member.

(b) The clamp drive mechanism has a pair of hydraulic cylinders that respectively drive the pair of rod members in a direction in which the pair of rod members approach and separate.

(c) The hydraulic cylinder is incorporated in a base member, and includes a cylinder body through which the rod member passes, and a piston provided integrally with the rod member.

(D) Each of the clamp members has a pair of upper and lower clamp rods extending in the approaching / separating direction, and a clamp head fixed to a tip portion of the clamp rods. It has a distal end guide part and a proximal end guide part for guiding a portion separated in the length direction of the clamp rod.

(e) A connecting plate for connecting the base end portion of each rod member and the portion between the distal end guide portion and the proximal end guide portion of the pair of clamp rods of the clamp member corresponding to the rod member is provided. .

[omega] The connecting plate is accommodated in a base member so as to be movable in the approaching / separating direction, and a guide member is provided for guiding the connecting plate so that the connecting plate is movable in parallel in the approaching / separating direction.

(G) A lubricant supply passage for supplying a lubricant to the screw groove is formed in the base member, and a thrust bearing is provided for rotatably supporting the cylindrical rotating member on the base member. A lubricant supply passage for supplying the lubricant to the base member is formed in the base member, and a lubricant supply passage for supplying the lubricant to the screw groove and a thrust bearing are provided. A lubricant supply passage for supplying the lubricant to the common passage is formed in the common passage.

[0022] (h) Each of the plurality of screw grooves is a three-thread groove, and three ball members respectively engaged with the three-thread grooves are provided as each set of engagement members. However, the plurality of screw grooves may be two screw grooves, and two ball members that respectively engage with the two screw grooves may be provided as each set of engaging members. In addition, as each screw groove, a plurality (two or three) of ball members may be engaged with each single screw groove. The invention's effect

[0023] According to the clamping device of the present invention, since the synchronous movement mechanism is provided, the pair of clamp members driven by the clamp driving mechanism are synchronously moved symmetrically with respect to the clamp reference position in the approaching / separating direction. The pair of clamp members can clamp the work on both sides to the clamp reference position. Especially, this synchronous movement mechanism has one pair of rod member, cylindrical rotating member, one pair of one or multiple screw grooves 2 pairs of engaging members are provided, the base end portions of a pair of rod members are connected to a pair of clamp members, and a cylindrical rotating member is externally fitted to the distal end portion of the pair of rod members. A pair of one or more thread grooves are formed on the tip side of the pair of rod members in reverse threads, and the cylindrical rotating member is supported on the base member so as to be rotatable around the axis of the rod member, and the cylindrical rotation 2 sets of engaging members on the inner circumference of the cylindrical rotating member Held in shape out collision on the shaft center side than were these two sets of engagement members engaged with the one or more conditions screw grooves of a pair.

That is, force can be transmitted between each rod member and the cylindrical rotating member via one or more screw grooves and a plurality of engaging members respectively engaged with one or more screw grooves. Since the force can be distributed to one or a plurality of screw grooves and a plurality of engaging members, an appropriate lead that does not apply a large load to the rod member or cylindrical rotating member for one or a plurality of screw grooves. Since it can be formed at an angle (for example, 45 degrees), a synchronous moving mechanism that operates smoothly can be configured, and the synchronous moving mechanism can be configured to have a desired high strength to increase durability, and a pair of clamp members can be formed. The cylindrical rotating member can be used as a common member for a pair of rod members, and the length of the cylindrical rotating member can be reduced. Can be reduced, and therefore The main portion having a cylindrical rotary member and a pair of the plurality Article screws grooves of the moving mechanism and the two pairs of engagement members is miniaturized, the clamp The device can be miniaturized as much as possible.

Brief Description of Drawings

FIG. 1 is a plan view of a clamping device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along line II-II of the clamp device of FIG.

FIG. 3 is a view corresponding to FIG. 2 in a state in which a pair of clamp members of the clamp device are separated as much as possible.

FIG. 4 is an enlarged view of the left half of FIG.

FIG. 5 is a right side view of the clamping device.

FIG. 6 is a cross-sectional view taken along line VI—VI in FIG.

FIG. 7 is a sectional view taken along line VI—VI in FIG.

FIG. 8 is a side view of a rod member.

FIG. 9 is a cross-sectional view of a rod member.

FIG. 10 is a cross-sectional view of an inner cylinder of a cylindrical rotating member.

FIG. 11 is a sectional view taken along line XI—XI in FIG.

FIG. 12 is a cross-sectional view of an outer cylinder of a cylindrical rotating member.

Explanation of symbols

[0026] 1 Clamping device

2 Base material

3 Clamp member

4 Guide mechanism

5 Clamp drive mechanism

6 plates

7 Guide pin (guide member)

8 Synchronous movement mechanism

20 Clamp rod

21 Clamp head

30 Tip guide

35 Base guide 40 Hydraulic cylinder

41 Cylinder body

46 Piston

70 Rod attachment

71 Cylindrical rotating member

72 3-thread screw groove

73 Ball member (engagement member)

78 Radial bearing

79 Thrust bearing

BEST MODE FOR CARRYING OUT THE INVENTION

[0027] The clamp device of the present invention includes a synchronous movement mechanism that synchronously moves a pair of clamp members driven by a clamp drive mechanism in the approaching / separating direction symmetrically with respect to a clamp reference position, The synchronous movement mechanism includes a pair of rod members, a cylindrical rotating member, a pair of multiple screw grooves, two sets of engaging members, a pair of rod member forces, and a pair of clamp members approaching and separating. The rod members are arranged so that their axial centers coincide with each other, the front ends of these rod members are opposed to each other, and the base end portions are connected to a pair of clamp members, respectively, and incorporated into the base member. Are supported in such a way that they can move in a direction away from and away from each other and are non-rotatable, and a cylindrical rotating member is externally fitted to the tip side part of the pair of rod members, and one pair is attached to the tip side part of the pair of rod members A plurality of screw grooves are formed in reverse threads The cylindrical rotating member is supported by the base member so as to be rotatable about the axis of the rod member, and two sets of engaging members project from the inner peripheral surface of the cylindrical rotating member toward the axis side of the cylindrical rotating member. The two sets of engaging members are engaged with a pair of screw grooves and are rotatably held in a shape.

Example

Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 and 2, the front, rear, left, right, top and bottom are defined based on the front left upper direction indicated by the arrow. Note that the direction in which the pair of clamp members 3 approach and separate is the left-right direction. As shown in FIGS. 1 to 7, the clamping device 1 includes a base member 2, a pair of left and right clamp members 3, a pair of left and right guide mechanisms 4, a pair of left and right clamp drive mechanisms 5, and a pair of left and right connecting plates. 6, left and right pair of guide members 7, synchronous mobile Structure 8 is provided. The clamping device 1 is formed symmetrically. Hereinafter, only one of the left and right symmetrical devices will be described as appropriate, and the other device will be given the same reference numeral as that of the other device and description thereof will be omitted.

As shown in FIGS. 1 to 7, the base member 2 includes a base body 10 and a pair of left and right side covers 11 fixed to both left and right ends of the base body 10. The base body 10 has a rectangular parallelepiped main body portion 10a elongated in the left-right direction, a flange portion 10b formed so as to project to the front and rear sides at the lower end of the main body portion 10a, and the upper side of the left and right ends of the main body portion 10a. It has a pair of upper and lower body parts 10c located on the left and right, and is formed in a concave shape that is wide on the left and right when viewed from the front.

Each side cover 11 is formed in substantially the same shape as the end surface of the base body 10 in a side view, and is fastened by a plurality of bolts 15 in contact with the end surface of the base body 10. For example, the main body upper portion 10c of the base main body 10 has a left-right width of about 1Z5 of the main body main portion 10a, and the side cover 11 has a left-right width of about 2Z3 of the main body upper portion 10c. The flange 10b of the base body 10 is fastened by a plurality of bolts 16 to a predetermined clamp base (not shown), and the clamp device 1 is fixed.

As shown in FIG. 1 to FIG. 4 and FIG. 7, the pair of clamp members 3 can clamp the workpiece to a predetermined clamp reference position from both the left and right sides above the base surface 10 d of the base member 2. They are facing each other. Each clamp member 3 has a pair of upper and lower clamp rods 20 extending in the left-right direction, and a clamp head 21 fixed to the tip of these clamp rods 20. The clamp head 21 is formed in a rectangular plate shape. Tip force of each clamp rod 20 Fastened with bolt 15 in a state of being fitted to clamp head 21, and most of each clamp rod 20 other than the tip side portion is attached to upper body 10c and side cover 11 of base member 2. Has been inserted.

[0032] As shown in Figs. 2 to 4 and 6, the left guide mechanism 4 guides the left clamp member 3 so that the left clamp member 3 can move in the left-right direction, and the right guide mechanism 4 4 guides the right clamp member 3 so that the right clamp member 3 can move in the left-right direction. Each guide mechanism 4 includes a distal end guide portion 30 and a proximal end guide portion 35 that guide a portion of the clamp member 3 that is separated in the length direction of each clamp rod 20. Here, a connecting plate accommodating space 2a is formed in the portion of the base member 2 where the main body upper portion 10c and the side cover 11 face each other. The distal end guide part 30 has a distal end guide cylinder 31, and this distal end guide cylinder 31 is fitted into the main body upper portion 10c of the base member 2 by being press-fitted from the connecting plate housing space 2a side. Cranprod 20 is slidably fitted into 31 via dust seal 32.

[0034] The base end guide portion 35 has a base end-bottomed guide tube 36, and this base end-bottomed guide tube 36 is attached to the side cover 11 of the base member 2 from the outside opposite to the connecting plate housing space 2a. The base end bottomed guide tube 36 is mounted by being screwed into the inner fit, and the tip end portion protrudes toward the connecting plate housing space 2a, and the clamp rod 20 slides on the base end bottomed guide tube 36. Fits freely. A breathing hole (not shown) is formed in the base member 2, and when the clamp rod 20 moves in the left-right direction due to the breathing hole formed in the breathing hole and the base member 2, the proximal bottomed guide tube 36 and the clamp are clamped. Air can be introduced into the space surrounded by the rod 20 and discharged.

As shown in FIGS. 2 to 4 and 6, the left clamp drive mechanism 5 drives the left clamp member 3 in the left-right direction, and the right clamp drive mechanism 5 moves the right clamp member 3 to the right. Drive left and right. These clamp drive mechanisms 5 have a pair of left and right hydraulic cylinders 40 that respectively drive the pair of rod members 70 in a direction in which the pair of rod members 70 of the synchronous movement mechanism 8 approach and separate from each other. Is incorporated in the base member 2. Here, the base main portion 10a of the base body 10 is formed with a relatively large-diameter mounting hole 10d that penetrates left and right. The pair of hydraulic cylinders 40 is mounted in the pair of large-diameter holes 10f.

Each hydraulic cylinder 40 has a cylinder body 41 through which the rod member 70 passes, and a piston 46 provided integrally with the rod member 70. The piston 46 is integrally formed with the rod member 70, but the piston 46 and the rod member 70 may be separate members and the piston 46 may be fixed to the rod member 70. The cylinder body 41 has a bottomed cylindrical cylinder member 42 and a rod-side end wall member 43 that is oil-tightly fixed to the open-side end of the cylinder member 42. The cylinder body 42 has a large-diameter hole 10f. It is fixed in an internal fit. The rod member 70 is passed through the cylinder member 42 and the rod end wall member 43 through the annular seals 44 and 45 so as to be oil-tightly slidable, and the piston 46 is oiled into the cylinder member 42 through the annular seal 47. It is fitted in a tightly slidable manner. [0037] Each hydraulic cylinder 40 is configured as a backward-acting hydraulic cylinder, and two hydraulic chambers 50, 55 are formed in the part surrounded by the cylinder body 41 and the rod member 70, with the piston 46 as a boundary. . Hydraulic ports 51 and 56 for supplying hydraulic pressure to the hydraulic chambers 50 and 55 are formed at the lower end of the base body 10, and the hydraulic passages 52 and 57 that connect the hydraulic ports 51 and 56 and the hydraulic chambers 50 and 55 are the base. The main body 10 and the cylinder member 42 are formed.

As shown in FIGS. 2 to 4, the left connecting plate 6 has a distal end guide portion 30 of the pair of clamp rods 20 of the base end portion of the left rod member 70 and the left clamp member 3. The right connecting plate 6 is connected to the proximal end portion of the right rod member 70 and the distal end guide portion of the pair of clamp rods 20 of the right clamp member 3. The part between 30 and the base end guide part 35 is connected. Each connecting plate 6 is accommodated in the connecting plate accommodating space 2a of the base member 2 so as to be movable in the left-right direction, and is fastened by a bolt 60 with the end of the rod member 70 fitted to the lower portion of the connecting plate 6. These are connected by a pin member 61 for preventing rotation.

[0039] A pair of clamp rods 20 in the middle of the pair of clamp rods 20 in the lengthwise direction are internally fitted on the upper part of the connecting plate 6, and a hook 20b formed on the clamp pad 20 and a stopper fitted on the clamp rod 20 The ring 20c is connected to the connecting plate 6 so as not to be relatively movable in the axial direction. The breathing hole formed in the base member 2 enables air to be introduced into and discharged from the connecting plate housing space 2a when the connecting plate 6 moves in the left-right direction.

As shown in FIGS. 2 to 6, the left guide member 7 is a guide extending in the left-right direction that guides the left connection plate 7 so that the left connection plate 6 can move horizontally in the left-right direction. The right guide member 7 comprises a guide pin 7 extending in the left-right direction for guiding the right connection plate 7 so that the right connection plate 6 can be translated in the left-right direction. Each guide pin 7 is inserted and fixed in a press-fit manner at both ends of the base body 10 and the side cover 11 in the vertical direction, and is arranged in the left-right direction so as to straddle the connecting plate accommodation space 2a. Thus, the central portion of the connecting plate 6 passes through the central portion in the vertical direction.

[0041] As shown in FIGS. 2 to 4 and 7 to 12, the synchronous movement mechanism 8 has a pair of clamp members 3 driven by a pair of clamp drive mechanisms 5 at a clamp reference position in the left-right direction. The pair of rod members 70 are arranged so as to be parallel to the approaching / separating direction of the pair of clamp members 3 and aligned with the center of the axis, with their tips facing each other. And A pair of rod members 70 whose base end portions are connected to a pair of clamp members 3 via guide plates 6, respectively, are fitted on the distal end side portions of the pair of rod members 70, and the axial center of the rod member 70 Cylindrical rotating member 71 supported by base member 2 so as to be able to rotate around, and a pair of three-thread screw grooves 72 formed at the distal end portion of a pair of rod members 70, which are formed as mutually reverse screws One pair of three-thread screw grooves 72 and a pair of three-thread screw grooves that are supported by the cylindrical rotation member 71 so as to protrude axially from the inner peripheral surface of the cylindrical rotating member 71 and are rotatable. Two sets of ball members 73 (engagement members 73) respectively engaged with 72 are provided.

[0042] As described above, the pair of cylinder members 40 is incorporated into the base member 2, and each rod member 70 is slidably inserted into the cylinder member 42 and the rod-side end wall member 43, and is connected to the connecting plate 6. By being connected via the non-rotating pin member 61, the pair of rod members 70 are supported so as to be movable in the left-right direction and non-rotatable, respectively.

The cylindrical rotating member 71 has a left and right length that can cover the tip side portions of the pair of rod members 70, and is attached to the small diameter hole lOe of the base body 10. The cylindrical rotating member 71 has an inner cylinder 75 and an outer cylinder 76, and the central portions of the inner cylinder 75 and the outer cylinder 76 in the left-right direction are connected by a plurality of radial pins 77. The outer cylinder 76 is not rotatable relative to the outer cylinder 76. It is not necessary to make the inner cylinder 75 and the outer cylinder 76 relatively non-rotatable, so the pin 77 can be omitted. The cylindrical rotating member 71 includes a pair of left and right radial bearings 78 mounted between the left and right ends and the small-diameter hole 10e, and a cylinder member 72 of the left and right ends and a pair of hydraulic cylinders 70. The base member 2 is supported by a pair of left and right thrust bearings 79 mounted between the base member 2 so as to be rotatable and immovable in the left-right direction.

[0044] The radial bearing 78 includes an annular race member 78a that contacts the small-diameter hole 10e, a plurality of cylindrical rollers 78b that roll on the inner peripheral surface of the race member 78a and the outer peripheral surface of the cylindrical rotating member 71, And a cage 78c that rotatably holds the plurality of cylindrical rollers 78b at appropriate intervals in the circumferential direction. The radial bearing 78 can be omitted. The thrust bearing 79 rotates a pair of annular race members 79a and 79b that abut against the opposing end surfaces of the cylinder member 42 and the cylindrical rotating member 71, and the opposing inner surfaces of the race members 79a and 79b. A plurality of cylindrical rollers 79c that move, and a cage 79d that rotatably holds the plurality of cylindrical rollers 79c at appropriate intervals in the circumferential direction. [0045] Each three-thread groove 72 is composed of three screw grooves 72 that are parallel and spiral, and the lead angle of these screw grooves 72 is set to an appropriate angle (for example, about 45 degrees). Thus, the pitches of the adjacent screw grooves 72 are all made the same and smaller. As each set of engaging members 73, three ball members 73 that are respectively engaged with the three-thread screw grooves 72 are provided. Next, a structure in which each set of three ball members 73 is held by the cylindrical rotating member 71 will be described.

[0046] In the inner cylinder 75 of the cylindrical rotating member 71, three ball receiving holes 75a are provided in the vicinity of the left and right ends, respectively, at three equal positions in the circumferential direction and at the same position in the left and right direction. The outer cylinder 76 of the cylindrical rotating member 71 is formed with substantially the same diameter as the ball member 73, and an annular ball engaging groove 76a is formed on the inner peripheral portion in the vicinity of both left and right ends thereof, with the ball receiving hole 71a. The cross-sectional shape is the same in the left-right direction and has the same curvature as the ball member 73. The three ball members 73 of each set are respectively received in the three ball receiving holes 75a and engaged with the three-thread screw grooves 72 in a state of being engaged with the common ball engaging grooves 76a. Yes.

[0047] Here, a pair of left and right lubricant supply passages 80 for supplying lubricant (for example, grease) to a pair of three screw grooves 72 of a pair of rod members 70 are paired with the base member 2. A pair of lubricating oil supply ports 85 formed in the cylinder member 42 of the hydraulic cylinder 40 and connected to the pair of lubricant supply passages 80 are attached to the front portion of the base member 2. These lubricating oil supply passages 80 are common to the pair of lubricating oil supply passages 80 for supplying a lubricant (for example, grease) to the pair of thrust bearings 79, and the lubricating oil passes through the thrust bearings 79. And supplied to the three-thread screw groove 72.

In addition, a pair of lubricating oil supply passages 81 for supplying lubricating oil to the pair of radial bearings 78 are connected to the cylinder member 42 of the pair of hydraulic cylinders 40 from the pair of lubricating oil supply passages 80. It is formed by branching. In other words, by injecting lubricating oil from the lubricating oil supply port 85, the lubricating oil is supplied to all of the three-thread screw groove 72, the radial bearing 78, and the thrust bearing 79 at a time.

Here, the cylinder main bodies 41 (rod end wall members 43) of the pair of hydraulic cylinders 40 are connected to each other by four axially long bolt members 90. When assembling the cylindrical rotating member 71, the pair of thrust bearings 79, and the pair of cylinder bodies 41, first, the bolt member 90 Before the fastening, in a state where these members 71, 79, 41 are in contact with each other, each rod side end wall member 43 is a step at the boundary with the large-diameter hole portion 10f positioned on the cylindrical rotating member 71 side. A gap of 0.5 to 1.0 mm is made between the part 10g, and a pair of rod side end wall members 43 are brought into close contact with the cylinder body 41 by a plurality of bolt members 90, and then further on the rod side. A pair of cylinder bodies 41 are fastened together in a direction in which the end wall member 43 approaches the stepped portion 10g, and a pair of thrust bearings 79 and a cylindrical rotating member 71 are interposed between the pair of cylinder bodies 41. It is inserted without play and assembled.

[0050] The effect of the clamping device 1 described above will be described.

One pair of clamp members 3 is driven in the approaching / separating direction by one pair of clamp drive mechanisms 5, and one pair of clamp members 3 driven by one pair of clamp drive mechanisms 5 is approached by a synchronous movement mechanism 8. It is synchronously moved symmetrically with respect to the clamp reference position in the separation direction. A pair of clamp members 3 and a synchronous movement mechanism 8 with a pair of clamp members 3 separated from each other by a distance larger than the width of the clamped part of the workpiece and the workpieces placed between the pair of clamp members 3. Thus, the pair of clamp members 3 are driven in the approaching direction and moved synchronously, and the workpiece is positioned and clamped at the clamp reference position by the pair of clamp members 3.

[0051] In the synchronous movement mechanism 8, the base end portions of the pair of rod members 70 are connected to the pair of clamp members 3 via the connecting plates 6, respectively, and are connected to the tip side portions of the pair of rod members 70. A pair of three-threaded screw grooves 72 are formed on the tip end portions of the pair of rod members 70 as opposite threads. The cylindrical rotating member 71 is supported by the base member 2 so as to be rotatable about the axis of the rod member 70, and two sets of ball members 73 are arranged on the cylindrical rotating member 71 more than the inner peripheral surface of the cylindrical rotating member 71. These two sets of ball members 73 are engaged with a pair of three-thread screw grooves 72 so as to protrude toward the center and rotate freely.

[0052] When the pair of rod members 70 move in the approaching / separating direction, the cylindrical rotating member 71 rotates through the three-thread screw groove 72 and the ball member 73, but the cylindrical rotating member 71, one pair The three screw grooves 72 and two pairs of ball members 73 move the pair of rod members 70 closer to each other and move synchronously in the direction of separation, and thus a pair of clamps connected to the pair of rod members 70. The member 3 is synchronously moved symmetrically with respect to the clamp reference position in the approaching / separating direction.

[0053] According to the clamping device 1, in particular, the synchronous movement mechanism 8 includes a pair of rod members 70, a cylindrical shape. Since the rotating member 71, a pair of three-thread screw grooves 72, and two pairs of ball members 73 are provided, the three-thread screw groove 72 and the three-thread screw groove between each rod member 70 and the cylindrical rotating member 71 are provided. 7 The force can be transmitted through the three ball members 73 respectively engaged with 2 and the force can be distributed to the three-thread screw groove 72 and the three ball members 73. Since it can be formed at an appropriate angle (an angle in the cross section in the axial direction: about 45 degrees) at which a large load does not act on the lid member 70 or the cylindrical rotating member 71, a synchronous movement mechanism 8 that operates smoothly can be configured. The synchronous movement mechanism 8 can be configured to have a desired high strength to enhance durability, and the pair of clamp members 3 can be reliably synchronously moved symmetrically with respect to the clamp reference position. As for the force, the cylindrical rotating member 71 is shared by a pair of rod members 70. Since the main part including the cylindrical rotating member 71 of the synchronous movement mechanism 8, the pair of three-thread screw grooves 72, and the two ball members 73 is miniaturized, the clamp device 1 is made as much as possible. Can be downsized.

[0054] Since the pair of rod members 70 are incorporated into the base member 2, the inside of the base member 2 can be used effectively, and the cylindrical rotating member 71 and the ball member 73 of the synchronous movement mechanism 8 are also incorporated into the base member 2. Therefore, the protection of the synchronous movement mechanism 8 and the safety for the operator can be enhanced, and the pair of rod members 70 can be moved in the left-right direction and cannot be rotated. Are supported by the base member 2, so that the pair of rod members 70 can be reliably operated so that the pair of clamp members 3 are synchronously moved symmetrically with respect to the clamp reference position.

[0055] The pair of clamp drive mechanisms 5 includes a pair of hydraulic cylinders 40 that respectively drive the pair of rod members 70 in directions in which the pair of rod members 70 approach and separate from each other. A powerful clamp driving force that drives the clamp member 3 can be output, so that a pair of the clamp members 3 can be reliably and synchronously moved symmetrically with respect to the clamp reference position. Although a very large load acts on 8, as described above, the synchronous movement mechanism 8 can be configured to have a desired high strength and durability can be enhanced, so that it can sufficiently withstand the load.

[0056] Since the pair of hydraulic cylinders 40 is incorporated in the base member 2, the inside of the base member 2 can be used effectively, and the protection of the hydraulic cylinder 40 and the safety for workers can be improved. Since the hydraulic cylinder 40 has a cylinder body 41 through which the rod member 70 penetrates and a piston 46 provided integrally with the rod member 70, the rod member 70 is used as an output member of the hydraulic cylinder 40. The rod member 70 and the hydraulic cylinder 40 can be arranged in a compact manner, and the base end portions of the pair of rod members 70 are appropriately separated from each other, and the workpiece is securely clamped by the pair of clamp members 3. It is possible to connect the pair of clamp members 3 and the base end portions of the pair of rod members 70.

[0057] Each clamp member 3 has a pair of upper and lower clamp rods 20 extending in the left-right direction and a clamp head 21 fixed to the distal end portion of these clamp rods 20, and the guide mechanism 4 includes each clamp rod 20 Since the distal end guide part 30 and the proximal end guide part 35 that guide the part separated in the longitudinal direction of the clamp member 3 are clamped, the clamp member 3 is moved in the horizontal direction so that the clamp member 3 does not rattle when clamping the workpiece. The workpiece can be securely guided to the clamp reference position and clamped securely.

[0058] The base end portion of each rod member 70 is connected to the portion between the distal end guide portion 30 and the base end guide portion 35 of the pair of clamp rods 20 of the clamp member 3 corresponding to the rod member 70. Since the connecting plate 6 is provided, the connecting plate 6 can securely connect the base end portion of the rod member 70 and the pair of clamp rods 20 so that the connecting plate 6 does not interfere with the guide mechanism 4.

[0059] Since the connecting plate 6 is accommodated in the base member 2 so that the connecting plate 6 can move in the left-right direction, the inside of the base member 2 can be effectively utilized, and the protection of the connecting plate 6 and the safety for the worker are enhanced. The clamp member 3 and the rod member 70 operate smoothly because the guide pin 7 is provided to guide the connecting plate 6 so that the connecting plate 6 can move in parallel in the left-right direction. Thus, the connecting plate 6 can be reliably guided.

[0060] Since the lubricant supply passage 80 for supplying the lubricant to the three-thread screw groove 72 of the rod member 70 is formed in the base member 2, the lubricant is easily and surely supplied to the three-thread groove 72. The friction between the three-thread screw groove 72 and the ball member 73 and between the ball member 73 and the cylindrical rotating member 71 can be reduced, and the durability can be reliably increased.

[0061] Since the radial bearing 78 and the thrust bearing 79 that rotatably support the cylindrical rotating member 71 on the base member 2 are provided, the cylindrical rotating member 71 can be smoothly rotated. Since the lubricant supply passages 80 and 81 for supplying the lubricant to the bearings 78 and 79 are formed in the base member 2, the lubricant can be supplied to the bearings 78 and 79 easily and surely. It is possible to reduce the friction of these bearings 78 and 79 and improve the durability.

[0062] The lubricant supply passage 80 for supplying the lubricant to the three-thread screw groove 72 and the lubricant supply passage 80 for supplying the lubricant to the thrust bearing 79 are formed in a common passage. The lubricant supply passage 80 can be easily and reliably formed in the base member 2.

It should be noted that the cylindrical rotating member 71 may be configured by one member without being divided into the inner cylinder 75 and the outer cylinder 76. In this case, three ball receiving holes 75a are formed in the cylindrical rotating member 71 that also serves as one member, and correspond to the three ball receiving holes 75a that are not connected by the common ball engaging groove 76a. Three partial spherical ball engagement holes are formed.

[0064] One of the pair of hydraulic cylinders 40 may be omitted. In this case, the clamp driving force is transmitted from one rod member 70 to the other rod member 70 by the synchronous movement mechanism 8, and the pair of clamp members 3 are synchronously moved. Various actuators such as a hydraulic motor and an electric motor can be used instead of the hydraulic cylinder 40. Further, instead of the three-thread screw groove 72, a two-thread screw groove may be provided, and two ball members that respectively engage with the two-thread screw groove may be provided as each set of engagement members 73. As a single screw groove instead of the triple screw groove 72, a plurality of (two or three) ball members may be engaged with the single screw groove. In addition, various modifications can be added without departing from the scope of the present invention.

Claims

The scope of the claims

[1] A base member, a pair of clamp members facing each other for clamping the workpiece to a predetermined clamping reference position on the upper side of the base surface of the base member, and a direction in which these clamp members approach and separate A clamp device comprising: a guide mechanism that guides a pair of clamp members so as to be freely movable; and a clamp drive mechanism that drives the pair of clamp members in the approaching / separating direction.

A synchronous movement mechanism is provided that synchronously moves a pair of clamp members driven by the clamp drive mechanism in the approaching / separating direction symmetrically with respect to the clamp reference position;

The synchronous movement mechanism is

A pair of rod members arranged in parallel to the approaching / separating direction and in such a manner that their axial centers coincide with each other, with the distal ends facing each other and the proximal end portions connected to a pair of clamp members, respectively.

A pair of rod members which are incorporated in the base member and are supported so as to be movable and non-rotatable toward and away from each other;

A cylindrical rotating member that is externally fitted to the tip side portion of the pair of rod members and is supported by the base member so as to be rotatable about the axis of the rod member;

A pair of one or a plurality of star groove grooves respectively formed on the tip side portions of the pair of rod members, and a pair of one or a plurality of screw grooves formed in reverse threads with respect to each other; Two sets of engaging members that are held by the cylindrical rotating member so as to protrude axially from the inner peripheral surface of the cylindrical rotating member, and are respectively engaged with the pair of one or more screw grooves. And a clamping device comprising:

[2] The clamp device according to [1], wherein the two sets of engaging members are rotatably held by cylindrical rotating members, respectively.

[3] The clamp according to claim 2, wherein the clamp driving mechanism has a pair of hydraulic cylinders that respectively drive the pair of rod members in a direction in which the pair of rod members approach and separate from each other. Lamp device.

4. The clamping device according to claim 3, wherein the hydraulic cylinder is incorporated in a base member, and has a cylinder body through which the rod member passes, and a piston provided integrally with the rod member.

[5] Each of the clamp members has a pair of upper and lower clamp rods extending in the approaching / separating direction, and a clamp head fixed to the tip of these clamp rods,

5. The clamp device according to claim 4, wherein the guide mechanism includes a distal guide portion and a proximal guide portion that guide a portion of each clamp rod that is separated in the length direction.

[6] A connecting plate that connects a base end portion of each rod member and a portion between the tip guide portion and the base end guide portion of a pair of clamp rods of the clamp member corresponding to the rod member. 6. The clamping device according to claim 5, wherein:

[7] The connecting plate is accommodated in a base member so as to be movable in the approaching / separating direction, and a guide member is provided for guiding the connecting plate so that the connecting plate is movable in parallel in the approaching / separating direction. The clamping device according to claim 6, wherein:

[8] A lubricant supply passage for supplying lubricant to the screw groove is formed in the base member, and a thrust bearing that rotatably supports the cylindrical rotating member on the base member is provided. A lubricant supply passage for supplying the material is formed in the base member, and the lubricant supply passage for supplying the lubricant to the screw groove and the lubricant supply passage for supplying the lubricant to the thrust bearing are common. The clamping device according to claim 1, wherein the clamping device is formed in the passage.

[9] The plurality of screw grooves are three screw grooves, and three ball members respectively engaging with the three screw grooves are provided as each set of engaging members.

The clamp apparatus in any one of 1-8.