JP5855909B2 - Clamping device - Google Patents

Description

  The present invention relates to a clamp device of a type in which a lever member is driven to swing by a fluid pressure cylinder, and to a device provided with a free piston that transmits a reaction force of a fluid force that clamps and drives the lever member to the upper surface of a base. .

  As shown in FIGS. 7 and 8, a clamp device 80 of a type that swings and drives a lever member 81 by a hydraulic cylinder 82 usually has a T-shaped leg portion 84 that engages with a T-groove 83 b of the base 83 and the base 83. A clamp body 85 having a base surface 86 supported by the upper surface 83a, and a lever member 81 pivotally attached to a pair of pivot portions 87 on the upper portion of the clamp body 85 via a pin member 88; A single-acting hydraulic cylinder 82 that is mounted on the clamp body 85 and drives the driven portion 89 of the lever member 81 to push upward, and a return mechanism 90 that returns the lever member 81 when the clamp is released. .

  When the clamp driving is performed, hydraulic pressure is supplied to the hydraulic working chamber 91, and the driven portion 89 at the rear end portion of the lever member 81 is pushed upward by the upper end portion of the piston member 92 to drive the front end of the lever member 81. The clamping object 94 such as a mold is pressed and fixed to the upper surface 83a of the base 83 by the pressing part 93 of the part. At this time, the hydraulic pressure D, which is the reaction force of the hydraulic pressure (load A) that clamps and drives the piston member 92 upward with the hydraulic pressure of the hydraulic working chamber 91 presses the rear part of the clamp main body 85 downward. The rear end portion of the base surface 86 is strongly pressed against the upper surface 83a of the base 83.

  On the other hand, since an upward load B acts on the pair of pivot portions 87 from the pin member 88, the front side portion of the clamp main body 85 moves upward, and the clamp main body 85 and the T-shaped leg portion 84 are lifted forward and inclined. Thus, the front end portion of the T-shaped leg portion 84 strongly presses the wall surface at the upper end of the wide groove portion of the T groove 83b with the concentrated load E. Therefore, unless the thickness and width of the wide portion at the lower end of the T-shaped leg portion 84 are increased, there is a problem that cracks occur and durability cannot be ensured.

Patent Document 1 discloses a clamp device that takes measures against the above-described problems.
In this clamping device, a hydraulic cylinder and a clamp main body portion incorporating the hydraulic cylinder are divided into a divided structure that is divided from the clamp main body, and the divided structure can be moved relative to the clamp main body in a vertical direction by a minute distance. It connects via a pair of pin members, and it is comprised so that the reaction force of the hydraulic pressure at the time of clamp drive with a hydraulic cylinder may act on the upper surface of the base | substrate which installs a clamp apparatus, without acting on a clamp main body.

No. 2-28000

In the clamping device shown in FIGS. 7 and 8, a concentrated load acts on the vicinity of the front end of the T-shaped leg when clamped, so that the load condition of the T-shaped leg is severe and the T-shaped leg is downsized. Is difficult.
In the clamp device of Patent Document 1, the clamp main body is composed of two members, and the split structure is connected to the clamp main body via a pair of pin members so as to be movable up and down. There is a problem that the production cost is increased due to increase.

According to another aspect of the present invention, there is provided a clamping device having a T-shaped leg portion that engages with a T-groove of the base and a base surface supported by the upper surface of the base, and a pair of pivots on the upper part of the clamp main body. A clamp apparatus comprising: a lever member pivotably mounted via a member; and a fluid pressure cylinder that is mounted on the clamp body and that drives and drives a driven portion of the lever member. A piston member that pushes and drives a driven portion of the member; a fluid pressure chamber that applies fluid pressure to the piston member; and a free piston that receives the fluid pressure in the fluid pressure chamber by partitioning one end of the fluid pressure chamber. The fluid pressure cylinder is a cylinder hole formed in a clamp body, and has a cylinder hole that is recessed to the upper end of the T-shaped leg and partially opens in a base surface, and the piston member Before A piston portion mounted in a cylinder hole, and the free piston is movably mounted in a portion deeper than the piston portion of the cylinder hole and disposed so as to be in contact with the upper surface of the base; The fluid pressure chamber is formed between the piston portion and a free piston in the cylinder hole, and is configured to support a fluid force acting on the free piston on an upper surface of the base.

According to a second aspect of the present invention, in the first aspect of the invention, the fluid pressure cylinder is a single-acting fluid pressure cylinder, and when the fluid pressure of the fluid pressure cylinder is released, the lever member is driven to return. A lever member return mechanism is provided.

The clamp device according to claim 3 is the invention according to claim 1 , wherein the fluid pressure cylinder is a single-acting fluid pressure cylinder, and when the fluid pressure of the fluid pressure cylinder is released, the piston member is a free piston. It is characterized in that a piston member for returning mechanism for driving return direction toward.

According to a fourth aspect of the present invention, in the invention of the first or second aspect , the spring for biasing the free piston toward the piston member is provided between the free piston and the upper end of the T-shaped leg. It is a feature.

  According to the first aspect of the present invention, the fluid pressure cylinder that pushes and drives the driven portion of the lever member includes the piston member that pushes and drives the driven portion of the lever member, and the fluid that applies fluid pressure to the piston member. A lever member is provided with a pressure chamber and a free piston that partitions one end of the fluid pressure chamber and receives the fluid pressure of the fluid pressure chamber, and the fluid force acting on the free piston is supported on the upper surface of the base. Since the reaction force of the fluid force that drives the clamp is supported on the upper surface of the base via the free piston, the clamp body is not pressed downward by the reaction force of the fluid force.

Only the upward force acting on the pair of pivots from the pin member acts on the clamp body, and the T-shaped leg portion of the clamp body extends over the entire length of the wall surface at the upper end of the wide groove portion of the T groove with a distributed load. Since it comes to press, concentrated load does not act on the front part of a T-shaped leg part, and size reduction of a T-shaped leg part can be achieved. Therefore, the manufacturing cost of the clamp device can be reduced, and the clamp device 1 can be mounted in a small T-groove, so the versatility of the clamp device is improved.
In addition, the depth of the cylinder hole is increased until it reaches the base surface, and a free piston that divides one end of the fluid pressure chamber is incorporated in the inner part of the cylinder hole, so the structure is simple, the number of parts is low, and the cost is low. It can be implemented.

In addition , the cylinder hole formed in the clamp body is recessed up to the upper end of the T-shaped leg, and opens partially in the base surface of the clamp body. Since the fluid pressure chamber is formed between the piston portion and the free piston, the fluid force acting on the free piston can be reliably supported on the upper surface of the base.

According to a second aspect of the present invention, the fluid pressure cylinder is a single-acting fluid pressure cylinder, and a lever member return mechanism is provided that drives the lever member to return when the fluid pressure of the fluid pressure cylinder is released. Therefore, the lever member can be reliably returned when the clamp is released.

According to the invention of claim 3, the fluid pressure cylinder is a single-acting fluid pressure cylinder, and when the fluid pressure of the fluid pressure cylinder is released, the piston member is driven to return in a direction approaching the free piston. Since the piston member return mechanism is provided, the piston member can be reliably returned when the clamp is released.

According to the invention of claim 4 , since the spring for urging the free piston toward the piston member is provided between the free piston and the upper end of the T-shaped leg, the hydraulic pressure in the fluid pressure chamber is released, When the clamp body is moved along the T-groove, it is possible to keep the free piston separated from the upper surface of the base and to prevent wear of the free piston.

It is a longitudinal cross-sectional view of the clamp apparatus (unclamped state) of Example 1 of this invention. It is a longitudinal cross-sectional view of the said clamp apparatus (clamp state). It is the rear view which looked at the said clamp apparatus (unclamped state) from back. It is the perspective view which looked at the said clamp apparatus from diagonally downward. It is a longitudinal cross-sectional view of the clamp apparatus (unclamped state) of Example 2. It is a longitudinal cross-sectional view of the clamp apparatus (clamp state) of FIG. It is a longitudinal cross-sectional view of the clamp apparatus (unclamped state) which concerns on a prior art. It is a longitudinal cross-sectional view of the clamp apparatus (clamp state) of FIG.

  Hereinafter, modes for carrying out the present invention will be described based on examples.

The clamping device according to the present embodiment is a hydraulic clamping device for fixing a clamping object such as a mold or a workpiece to the upper surface of a base (base member, table, bolster). In this embodiment, “hydraulic pressure” means oil in a compressed state.
As shown in FIGS. 1 to 4, the clamp device 1 includes a clamp body 2, a lever member 3 pivotally attached to the clamp body 2, a pin member 4, and a driven portion 16 of the lever member 3. And a hydraulic cylinder 5 (fluid pressure cylinder). In the present embodiment, the direction of arrow F is assumed to be the front, and the direction of arrow R is assumed to be the rear.

  The steel clamp body 2 is integrally formed with the base surface 10 supported by the upper surface 6 a of the base 6 and the clamp body 2 so as to protrude below the base surface 10, and the T-groove 6 b of the base 6. And a pair of left and right pivot portions 12 that pivotally support the pin member 4 formed on the upper portion of the clamp body 2. The pair of left and right pivot parts 12 are integrally formed so as to protrude upward from the left part and the right part of the front part of the clamp body 2. The pivot 12 is formed with a horizontal pin pivot hole 13 in the left-right direction.

  The T-shaped leg portion 11 has an inverted T-shaped longitudinal section when viewed from the front, is formed over the entire length in the center in the width direction of the clamp body 2, and is engaged with the T-groove 6 b of the base 6. It can move in the T-groove 6b. The base surface 10 is formed on a horizontal plane located on the left and right sides of the upper end of the T-shaped leg 11. The lever member 3 is a steel member that is elongated in the front-rear direction. A pressing portion 15 that presses the clamp object 14 is formed at the lower end of the front end portion of the lever member 3, and a hydraulic pressure is applied to the lower end of the rear end portion of the lever member 3. A driven portion 16 that is clamped upward by the cylinder 5 is formed, and a horizontal pin hole 17 in the left-right direction is formed at a slightly rear portion of the central portion in the length direction of the lever member 3. By inserting the pin member 4 through the pin pivot hole 13 of the pair of pivot portions 12, the lever member 3 is pivotally attached by the pin member 4.

  The hydraulic cylinder 5 is a single-acting hydraulic cylinder, and is disposed vertically at the rear portion of the clamp body 2. The hydraulic cylinder 5 includes a cylinder hole 18 formed in the rear portion of the clamp body 2, a piston member 19 that pushes and drives the driven portion 16 of the lever member 3, and a hydraulic operation chamber that applies hydraulic pressure to the piston member 19. 18a (fluid pressure chamber) and a free piston 20 that partitions one end (lower end) of the hydraulic working chamber 18a and receives the hydraulic pressure of the hydraulic working chamber 18a.

  The piston member 19 has a piston portion 19a slidably mounted in the cylinder hole 18 at the lower end portion, and a seal member 19b for oil-tight sealing is mounted on the outer peripheral portion of the piston portion 19a. An annular guide member 21 that has an insertion hole 21a through which the piston member 19 is inserted and that guides the piston member 19 is fixed to the clamp body 2 with a plurality of bolts 21b. The insertion hole 21a is formed to have a slightly smaller diameter than the cylinder hole 18. The annular guide member 21 constitutes a part of the clamp body 2.

  The cylinder hole 18 is recessed from the upper end of the clamp body 2 to the upper end portion of the T-shaped leg portion 11 and partially opens in the base surface 10. The free piston 20 is movably attached to a portion of the cylinder hole 18 that is deeper than the piston portion 19 a and is disposed so as to be able to contact the upper surface 6 a of the base 6. A seal member 20a for oil-tight sealing is mounted on the outer peripheral portion of the free piston 20.

  The hydraulic working chamber 18a is formed in the cylinder hole 18 between the piston portion 19a and the free piston 20, and the free piston 20 is configured to partition one end of the hydraulic working chamber 18a and receive the hydraulic pressure in the hydraulic working chamber 18a. . The hydraulic working chamber 18a is connected to a hydraulic pressure supply source via a hydraulic supply path (not shown), and is configured so as to supply hydraulic pressure to the hydraulic working chamber 18a and to release the hydraulic pressure. When the lever member 3 is clamp-driven, the hydraulic pressure acting on the free piston 20 by the hydraulic pressure in the hydraulic working chamber 18a is supported by the upper surface 6a of the base 6.

  A compression spring 22 that urges the free piston 20 toward the piston member 19 is provided between the free piston 20 and the upper end of the T-shaped leg portion 11. That is, a circular recess 23 having an open lower end is formed at the center of the lower portion of the free piston 20, a recess 24 is also formed at the upper end of the T-shaped leg 11, and the upper half of the compression spring 22 is a circular recess. 23, and the lower end portion of the compression spring 22 is received in the recess 24.

A lever member return mechanism 25 that drives the lever member 3 back to the original position when the hydraulic pressure in the hydraulic working chamber 18a of the hydraulic cylinder 5 is released when the clamp is released is provided.
The lever member return mechanism 25 includes a cylindrical hole 26 formed vertically in the clamp body 2 on the front side of the hydraulic cylinder 5 and a recess formed in a lower open portion in the vicinity of the rear side of the pin hole 17 in the lever member 3. 27, a bolt member 28, and a compression spring 29.

A rod hole 30 is formed in a wall portion that closes the upper end of the cylindrical hole 26, a compression spring 29 is accommodated in the cylindrical hole 26, and the bolt member 28 extends upward from the rod hole 30 through the compression spring 29. A cylindrical member 31 is screwed to the upper end portion of 28.
The left and right end portions of the horizontal support rod 32 penetrating through the cylindrical member 31 are rotatably supported by the wall portions of the lever member 3 on both sides of the recess 27, and the lower end of the compression spring 29 is interposed via the ring member 33. The lever member 3 is elastically urged downward (return direction) by the bolt member 28 and the compression spring 29.

The operation and effect of the clamping device 1 described above will be described.
As shown in FIG. 1, in a state where the hydraulic pressure in the hydraulic working chamber 18a is released (released), the lever member return mechanism 25 causes the lever member 3 to return and swing to the maximum, and the driven portion 16 The upper end of the annular guide member 21 is received, the piston member 19 is lowered to the maximum, the free piston 20 is lifted to the maximum by the urging force of the compression spring 22, and the lower surface of the free piston 20 is not in contact with the upper surface 6a of the base 6 become. Therefore, when the clamp device 1 is moved horizontally, the free piston 20 does not come into contact with the upper surface 6 a of the base 6. Therefore, wear due to contact between the free piston 20 and the upper surface 6a of the base 6 is reliably prevented.

  As shown in FIG. 2, when the clamping device 14 is fixed (clamped) to the upper surface 6 a of the base 6 by the clamping device 1, when hydraulic pressure is supplied to the hydraulic working chamber 18 a, the hydraulic pressure in the hydraulic working chamber 18 a is changed to the piston member 19. Is driven upward to drive the driven portion 16 of the lever member 3 upward.

At this time, the hydraulic pressure in the hydraulic working chamber 18 a acts on the free piston 20, the free piston 20 moves downward against the urging force of the compression spring 22, and the lower surface of the free piston 20 moves to the upper surface 6 a of the base 6. It comes into contact. That is, the reaction force of the hydraulic pressure for driving the clamp is supported by the upper surface 6 a of the base 6 via the free piston 20. Then, the load A that drives the lever member 3 upward by the piston member 19 is transmitted to the pair of pivot portions 12 via the pin member 4, and the upward load B acts on the pair of pivot portions 12.

Due to the upward load B, the entire clamp body 2 is driven to be pushed upward while maintaining a horizontal posture, and the T-shaped leg portion 11 is applied to the wall surface 6c at the upper end of the wide groove portion of the T groove 6b over the entire length. Abut. Therefore, a substantially uniform distributed load C acts on the wall surface 6c of the T groove 6b from the entire T-shaped leg portion 11.
Therefore, the load condition of the T-shaped leg portion 11 is remarkably relieved, so that the durability of the T-shaped leg portion 11 and the T-groove 6b is improved and the T-shaped leg portion 11 can be downsized. Therefore, the manufacturing cost of the clamp device 1 can be reduced, and the clamp device 1 can be attached to the small T-groove 6b, so that the versatility of the clamp device 1 is improved.

Next, a clamp device 1A according to the second embodiment will be described with reference to FIGS.
However, the same reference numerals are given to the same members as those of the clamping device 1 and the description thereof is omitted, and different configurations will be mainly described.
As shown in FIGS. 5 and 6, in this clamping device 1A, the hydraulic cylinder 5A is a single-acting hydraulic cylinder. The hydraulic cylinder 5A includes a piston member 19A that pushes and drives the driven portion 16 of the lever member 3, a hydraulic operating chamber 40 that applies hydraulic pressure to the piston member 19A, and one end of the hydraulic operating chamber 40 that partitions the hydraulic cylinder 5A. And a free piston 20 </ b> A that receives the hydraulic pressure of the working chamber 40. The hydraulic pressure acting on the free piston 20 </ b> A is supported by the upper surface 6 a of the base 6.

A flange 41 is formed at the upper end of the free piston 20A. Annular guide member 42 constitutes a part of the clamp body 2 is fixed more to the clamp body 2 into a plurality of bolts. The annular guide member 42 has a cylindrical portion 43 that extends downward. The cylinder hole 44 includes a lower cylinder hole 44a formed in the clamp body 2, a middle cylinder hole 44b having a diameter larger than that of the lower cylinder hole 44a, a cylinder part 43, and a diameter larger than that of the lower cylinder hole 44a. The upper cylinder hole 44c is smaller in diameter than the middle cylinder hole 44b, and the guide cylinder hole 44d is formed in the cylindrical part 43 and slightly smaller in diameter than the upper cylinder hole 44c.

  Piston portions 45 other than the flange 41 of the free piston 20A are slidably mounted in the lower cylinder hole 44a, and the flange 41 of the free piston 20A is slidably mounted in the middle cylinder hole 44b. The lower end flange 46 is slidably mounted in the upper cylinder hole 44c, and the ram body 47 of the piston member 19A is slidably mounted in the guide cylinder hole 44d.

  A seal member 48 for oil-tight sealing is attached to the outer peripheral portion of the piston portion 45 of the free piston 20A, and a seal member 49 for oil-tight sealing is attached to the inner peripheral portion of the guide cylinder hole 44d. The hydraulic working chamber 40 is formed in the cylinder hole 44 between the piston member 19A and the free piston 20A.

When the hydraulic pressure of the hydraulic cylinder 5A is released, a piston member return mechanism 50 is provided that drives the piston member 19A to return in a direction approaching the free piston 20A.
Next, the piston member return mechanism 50 will be described.
The piston member 19A is formed with an accommodation hole 51 having an open lower end. Upper column member 52 having a flange portion 52a is provided inside the housing hole 51 and the hydraulic chamber 40, bolt holes 5 5 is formed in a lower portion of the pillar member 52, the upper end center of the free piston 20A A circular recess 54 is formed.

  The columnar member 52 is fixed to the free piston 20A by fitting the lower end portion of the columnar member 52 into the circular recess 54 and screwing the bolt 56 inserted from below into the bolt hole 55 of the free piston 20A into the bolt hole 53. A compression spring 57 is externally mounted on the columnar member 52 in the accommodation hole 51, and the upper end of the compression spring 57 is received by the flange 52 a, and the lower end of the compression spring 57 is connected to the piston via the ring member 58 and the stop ring 59. It is received by the member 19A. The accommodation hole 51 constitutes a part of the hydraulic working chamber 40. The piston member 19A is elastically biased toward the free piston 20A by the piston member return mechanism 50.

Next, the operation and effect of the clamp device 1A will be described.
In the unclamped state in which the hydraulic pressure in the hydraulic operating chamber 40 is released as shown in FIG. 5, the lever member 3 swings back to the maximum and the piston member 19A descends to the maximum, as in the clamp device 1 of the first embodiment. The free piston 20 </ b> A is raised to the maximum, and the free piston 20 </ b> A maintains a state in which the lower surface thereof floats higher than the upper surface 6 a of the base 6. The lower end of the piston member 19 </ b> A is in contact with the upper end of the free piston 20 </ b> A, and the upper end of the columnar member 52 is in contact with the upper end wall surface of the accommodation hole 51.

Next, as shown in FIG. 6, when hydraulic pressure is applied to the lever member 3 to the hydraulic chamber 40 for driving clamping, the piston member 19A is increased in pressure the oil pressure of the oil pressure operating chamber 40, the lever member 3 The driven part 16 is pushed upward, and the free piston 20 </ b> A receives the hydraulic pressure in the hydraulic working chamber 40 and descends, and is supported in contact with the upper surface 6 a of the base 6.

  Therefore, similarly to the clamp device 1 of the first embodiment, the clamp body 2 rises while maintaining the horizontal posture, and the T-shaped leg portion 11 extends over the entire length to the wall surface 6c of the wide groove portion of the T groove 6b. Abut. Therefore, a substantially uniform distributed load acts on the wall surface 6c of the T groove 6b from the entire T-shaped leg portion 11. In addition, the same operations and effects as those of the first embodiment are obtained.

Next, an example in which the above embodiment is partially changed will be described.
(1) Although the single acting hydraulic cylinders 5 and 5A are employed in the clamping devices 1 and 1A, a double acting hydraulic cylinder may be employed.
(2) The clamping devices 1 and 1A of the first and second embodiments are merely examples, and the present invention can be applied to various types of clamping devices in which the lever member is driven to swing by a fluid pressure cylinder.

(3) In the clamping devices 1 and 1A of the first and second embodiments, the case where a hydraulic cylinder is employed as the fluid pressure cylinder has been described as an example. However, the present invention is also applied to a clamping device employing an air cylinder instead of the hydraulic cylinder. The same can be applied.
(4) Those skilled in the art can implement the present invention in various forms added with various modifications without departing from the spirit of the present invention, and the present invention includes such modifications.

The present invention can be applied to a clamping device for fixing the various clamping objects such as dies and work pallet and the workpiece, it is the also on useful industry.

DESCRIPTION OF SYMBOLS 1,1A Clamp apparatus 2 Clamp main body 3 Lever member 4 Pin member 5, 5A Hydraulic cylinder 10 Base surface 11 T-shaped leg part 12 Pivot part 16 Driven part 19, 19A Piston member 20, 20A Free piston 18a, 40 Hydraulic working chamber 18, 44 Cylinder hole 19a Piston portion 22 Compression spring 25 Lever member return mechanism 50 Piston member return mechanism

Claims (4)

A clamp body having a T-shaped leg portion that engages with the T-groove of the base and a base surface supported by the upper surface of the base, and a pair of pivots on the upper portion of the clamp main body are swingable via a pin member. In a clamp device having a pivoted lever member and a fluid pressure cylinder mounted on the clamp body and drivingly driving a driven portion of the lever member,
The fluid pressure cylinder includes a piston member that pushes and drives the driven portion of the lever member, a fluid pressure chamber that applies fluid pressure to the piston member, and one end of the fluid pressure chamber that partitions one end of the fluid pressure chamber. A free piston for receiving pressure,
The fluid pressure cylinder is a cylinder hole formed in the clamp body, and has a cylinder hole that is recessed to the upper end of the T-shaped leg and partially opens in the base surface.
The piston member has a piston portion mounted in the cylinder hole,
The free piston is movably attached to a portion of the cylinder hole that is deeper than the piston portion and is disposed so as to be able to contact the upper surface of the base.
The fluid pressure chamber is formed between the piston portion and a free piston in the cylinder hole,
A clamping device characterized in that a fluid force acting on the free piston is supported by an upper surface of the base. The fluid pressure cylinder is a single-acting fluid pressure cylinder,
When said fluid pressure of the fluid pressure cylinder is released, the clamping device according to claim 1, characterized in that a lever member for returning mechanism for returning driving the lever member. The fluid pressure cylinder is a single-acting fluid pressure cylinder,
When said fluid pressure of the fluid pressure cylinder is released, the clamping device according to claim 1, characterized in that a piston member for returning mechanism for driving return direction toward said piston member to the free piston. The clamping device according to the spring biasing, to claim 1 or 2, characterized in that provided between the upper end portions of the free piston and the T-leg portion free piston towards the piston member.