JP2000109297A - Clamp device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a clamp device that can grip a plurality of loads reliably irrespective of their rigidity, and is simple is structure and relatively inexpensive to manufacture. SOLUTION: An arm portion 24 of each clamp arm 16 has a holding portion 30 recessed in a clamp surface 16a, and a curved wall surface 32 defined within the holding portion 30 to support a movable grip member 20 movably. The movable grip member 20 has first grip surfaces 34a extending linearly along the arm portion 24 in projected related to the clamp surface 16a of the arm portion 24, and a support surface spreading on the counter side to the first grip surfaces 34a which is covered with the holding portion 30 and extending arcuately along the arm portion 24 and concavely to the first grip surfaces 34a. The support surface has the substantially same curvature as the curved wall surface 32 of the arm portion 24 so as to come into uniform sliding contact with it. In the contact state, the movable grip member 20 is movable back and forth along the arm portion 24 about the center axis of the curved wall surface 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clamp device having a pair of arms for holding an object.

[0002]

2. Description of the Related Art Conventionally, in the field of forklifts, there has been known a type in which a clamp device for directly sandwiching and transporting a load not mounted on a pallet can be replaced with a pallet fork. In general, a clamp device of a forklift is generally supported by a clamp base attached to a front surface of a lift bracket attached to a mast so as to be able to move up and down, and detachably attached to a front surface of the clamp base and movable in a horizontal direction via a rail mechanism. A pair of left and right clamp arms, and a drive cylinder that moves the clamp arms toward and away from each other.

[0003] In this type of clamping device, the opposing surfaces of a pair of clamp arms, that is, the clamping surfaces are provided for the purpose of improving the engagement between the side surface of the load to be clamped and the clamping surfaces and reducing stress concentration. For example, those provided with a rib-shaped projection or a flat pad are well known. In addition, in order to be able to collectively hold a plurality of loads juxtaposed in the horizontal direction, a movable pad that can adjust the angle of the pad surface with respect to the clamp arm to follow the side shape of the stack of the loads is provided. A clamping device having the same has already been proposed (for example, Japanese Patent Application Laid-Open No. 7-48100,
No. 41295).

[0004] In the conventional forklift clamping apparatus, the rigidity of the object to be clamped is relatively high.
In some cases, the clamp arm is designed on the assumption that a sufficient clamping force can be applied to a load. In this case, it is assumed that the load does not deform and the clamp arm itself bends to some extent under the clamping force applied to the pair of clamp arms by the drive cylinder during clamping. Therefore, the distance between the clamp surfaces of the pair of clamp arms is
At no load, the mounting angle of the two clamp arms to the clamp base is set such that the free end at the distal end remote from the clamp base is narrower than the proximal end adjacent to the clamp base.

[0005]

The design of such a clamp arm in a conventional clamping device is such that the rigidity of the load is relatively high, such as a flexible box or bag containing fluid contents. When low, inconvenience occurs. In other words, it is necessary for both clamp arms to hold the load with such a clamping force that does not damage or deform the load, and it is difficult to flex the clamp arm itself. become. As a result, it may be difficult to clamp the load arranged on the side close to the clamp base among the plurality of loads stacked side by side in the horizontal direction by the base end portions of both clamp arms.

In order to solve such a problem, for example, in a clamp device having a movable pad described in Japanese Patent Laid-Open No. 7-48100 described above, each of a plurality of pads arranged side by side in the extension direction of the clamp arm, that is, in the front-back direction. Since each of the clamp arms is individually swingably supported via the spherical support structure and is spring-biased in the clamp direction, a large clamping force enough to bend the clamp arms is not required, and the free end side portions of both clamp arms are required. It is expected that the load can be sandwiched by both the and the proximal portion. However, since a plurality of pads are independently supported on the clamp arm via the spherical support structure and the spring, the pad support structure tends to be relatively complicated.

In the clamp device having a movable pad described in Japanese Patent No. 2541295, a plurality of pads arranged in the longitudinal direction of the clamp arm can swing on the clamp arm via a common holder. Since it is supported, it is expected that the load can be held by both the free end side portion and the base end side portion of both clamp arms without requiring a large holding force enough to deflect the clamp arm. However, since the holder is connected to the clamp arm via one support shaft, and the support shaft receives all of the clamping force applied to the clamp arm, the rigidity of the support shaft and the bearing is minimized. It is necessary to increase the manufacturing cost, and as a result, the manufacturing cost of the clamping device may increase.

[0008] An object of the present invention is to provide a clamp device designed so that the distance between the clamp surfaces of a pair of arms is smaller at the free end side than at the base end side when there is no load, and the rigidity of the object to be clamped is compared. A high-performance clamping device that can hold the object between the free end and the base end of both arms with a clamping force that does not damage or deform the object even when it is weak. Is to provide. Another object of the present invention is to provide a clamp device having such a high-performance clamp device, which has a movable-portion support structure capable of dispersively supporting a clamping force applied to an arm, and can be manufactured at a relatively low cost with a simple structure. To provide.

[0009]

According to a first aspect of the present invention, there is provided a base and a base extending substantially in the same direction with respect to the base, facing each other, approaching and separating from each other. In a clamp device including a pair of arms that can move relatively to each other, and a movable holding member that is respectively installed on the mutually facing surfaces of the arms, each of the pair of arms includes:
A concave portion is provided on the mutually facing surfaces, and a storage portion for storing the movable holding member, and a support portion installed in the storage portion and movably supporting the movable holding member, wherein the movable holding member is provided on each of the pair of arms. A holding surface extending in the direction in which the arm extends at a position protruding from the mutually facing surfaces, and a support surface extending in an arc shape in the direction in which the arm extends in the housing portion and engaging with the support portion. A clamping device is provided.

According to a second aspect of the present invention, in the clamping device according to the first aspect, the support surface of the movable holding member is formed as a part of a cylindrical surface, and the support portion of the arm has the same curvature as the support surface. Provided is a clamp device having a curved wall surface that extends in the direction in which the arm extends and evenly contacts the support surface.

According to a third aspect of the present invention, in the clamping device according to the first aspect, the support surface of the movable holding member is formed as a part of a cylindrical surface, and the support portion of the arm is parallel to the central axis of the support surface. Provided is a clamping device including a plurality of cylindrical columns that are distributed in an extending direction of an arm and have a central axis.

According to a fourth aspect of the present invention, in the clamping device according to any one of the first to third aspects, the holding surface of the movable holding member is separated from the base end region of the arm adjacent to the base and the base. And a clamp device extending continuously between the arm and the distal region of the arm. According to a fifth aspect of the present invention, there is provided the clamp device according to any one of the first to fourth aspects, wherein a plurality of movable holding members are installed on each of the pair of arms.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments with reference to the accompanying drawings. In the drawings, the same or similar components are denoted by common reference numerals. In the following embodiments, the present invention is shown as an example in which the present invention is applied to a clamp device of a forklift. However, the present invention is not limited to this, and can be applied to other various forms of clamp devices.

Referring to the drawings, FIGS. 1 and 2 show a clamping device 10 according to a first embodiment of the present invention. The clamp device 10 includes a clamp base 14 attached to a front surface of a lift bracket 12 that is attached to a mast (not shown) of a forklift so as to be able to move up and down, and a clamp base 14.
A pair of left and right clamp arms 16 supported detachably on the front surface of the device and movable in the left and right horizontal direction via a rail mechanism to be described later, and a pair of clamp arms 16 for selectively moving the clamp arms 16 toward and away from each other. , And a movable holding member 20 provided on each of the mutually opposing surfaces of the clamp arms 16, that is, the clamp surfaces 16a.

On the front surface of the clamp base 14, two sets of upper and lower rail guides 22 extend in the left-right horizontal direction in parallel with each other. On the other hand, each clamp arm 16 is
An arm 24 having a pair 6a and a pair of upper and lower rails 26 extending in a direction substantially perpendicular to the arm 24 are integrally provided. One set of rail portions 26 of each clamp arm 16
Are slidably received by a pair of upper and lower rail guides 22. Therefore, the pair of clamp arms 16 are supported on the front surface of the clamp base 14 via the rail mechanism including the respective rail portions 26 and the corresponding rail guides 22, and the respective arm portions 24 are mounted on the clamp base 14. On the other hand, it extends forward and selectively opens and closes to approach and move away from each other under the drive of the corresponding drive cylinder 18.

The clamp device 10 is designed on the assumption that the load 28 to be clamped has a relatively high rigidity and that a sufficient clamping force can be applied to the load 28 by the clamp arm 16. That is, at the time of clamping, under the clamping force applied to both clamp arms 16 by the drive cylinder 18,
The load 28 is not deformed and the arm portion 24 of the clamp arm 16 is not deformed.
It is assumed that it will bend to some extent. Therefore, as shown in FIG.
The distance between the clamp surfaces 16a of the first and second clamp surfaces 16a at the end, that is, the distance G on the free end side away from the clamp base 14 when no load is applied.
1 is a distance G2 on the base end side adjacent to the clamp base 14.
It is set to be narrower than

When the clamp device 10 clamps a load 28 having relatively low rigidity, such as a flexible box or bag-like body containing a fluid content, both clamp arms 16 are attached to the load 28. It is necessary to hold the load 28 with a holding force that does not cause damage or deformation, and therefore, it is difficult to bend the arm portion 24 of the clamp arm 16 itself. In that case, in the conventional clamping device, the clamp base 1 of the plurality of stacks of loads 28 juxtaposed in the horizontal direction is used.
It has become difficult to hold the load 28 disposed on the side closer to 4 between the base end portions of both arm portions 24. Therefore,
In the clamp device 10 according to the embodiment of the present invention, the movable holding member 20 is provided on the clamp surface 16 a of each clamp arm 16.
Is provided, the load 28 can be held by both the free end side portion and the base end side portion of the both arm portions 24 without bending the arm portions 24 themselves.

As shown in FIGS. 3 to 5, the arm portion 24 of each clamp arm 16 is recessed in the clamp surface 16 a and accommodates the accommodating portion 30 accommodating the movable holding member 20 and the accommodating portion 30. And a support portion 32 for movably supporting the movable holding member 20 with respect to the arm portion 24. The accommodation part 30 is formed as a bottomed hollow part having a rectangular opening 30a extending to the outer peripheral area of the clamp surface 16a. The support portion 32 is formed in the accommodation portion 30 in an arc shape in the extending direction of the arm portion 24 with respect to the clamp base 14, and has a rectangular opening 3.
It is composed of a curved wall surface 32 protruding toward the 0a side. The curved wall surface 32 is a part of a cylindrical surface having a center axis (not shown) that is substantially perpendicular to the upper and lower end surfaces 24 a of the arm portion 24, and the back surface opposite to the clamp surface 16 a on the free end side of the arm portion 24. 16b and the arm 24
Is connected to the inner wall surface 24b of the arm portion 24 at the base end side.
Therefore, the accommodating portion 30 includes the curved wall surface 32 and the arm portion 2.
4 are defined by four inner wall surfaces 24b before and after four,
An opening is formed on the back surface 16b on the free end side of the arm portion 24.

The movable holding member 20 is connected to each clamp arm 1.
A pair of first portions 34 of the sixth arm portion 24 that can protrude from the clamp surface 16a and a second portion 36 that can be housed in the housing portion 30 are integrally provided. The pair of first portions 34 of the movable holding member 20 are arranged along both upper and lower edges of the second portion 36, and the arm portions 24 project from the clamp surface 16a.
Each has a first holding surface 34a that extends linearly in the direction in which it extends. The second portion 36 of the movable holding member 20 is disposed so as to be exposed at the rectangular opening 30a of the housing 30, and extends substantially in parallel with the first holding surface 34a.
And a support surface 36b concealed in the housing portion 30 on the opposite side of the second holding surface 36a and extending in an arc shape in the extending direction of the arm 24 and in a concave shape toward the second holding surface 36a. The support surface 36b of the second portion 36 is a portion of a cylindrical surface having substantially the same curvature as the support portion of the arm portion 24, that is, the curved wall surface 32, and is uniformly contacted with the curved wall surface 32 to engage in a sliding manner. Combine.

At the upper end surface and the lower end surface of the second portion 36 of the movable holding member 20, flanges 38 protruding in an arc shape along the support surface 36b are respectively provided. On the other hand, the holding portion 30 of the arm portion 24 of the clamp arm 16 has a holding plate 40 on a flat belt along the upper edge and the lower edge of the rectangular opening 30a.
Are fixed respectively. Each flange 38 of the movable holding member 20 has a curved wall surface 32
At the position closest to “a”, it is slidably sandwiched between the curved wall surface 32 and each of the holding plates 40, and contacts the upper and lower inner wall surfaces 24 b of the arm 24 (FIG. 5). Thereby, the movable holding member 20 is held so as not to fall out of the housing portion 30 of the arm portion 24 and to prevent rattling in the housing portion 30.

In this state, the movable holding member 20 moves along the cylindrical surface having a predetermined curvature around the central axis of the curved wall surface 32 while its support surface 36b and the curved wall surface 32 of the arm portion 24 are in uniform contact. The arm 24 can rotate in the front-rear direction as shown by the arrow P in the figure. Such a turning operation of the movable holding member 20 is defined in a range until the front end surface or the rear end surface of the second portion 36 of the movable holding member 20 collides with the front inner wall surface 24b or the rear inner wall surface 24b of the arm portion 24. (FIG. 4).

The curved wall surface 32 of the arm 24 and the support surface 36b of the movable holding member 20 can be bent to a predetermined curvature by various methods. However, from the viewpoint of mass productivity and cost, the curved surface is formed by bending an iron plate. It is advantageous to do so. In this case, the arm portion 24 and the movable holding member 20
Instead of a solid body as shown, it is formed as a hollow box body formed by combining iron plates.

The clamping device 10 having the above-described structure has the following very advantageous effects. First, regardless of the rotational position of the movable holding member 20, the pair of first portions 3
4 is the second holding surface 3a of the second portion 36.
6a and the clamp arm 16 are arranged so as to protrude from the clamp surface 16a of the arm portion 24 (FIGS. 4A and 4B). At this time, both first portions 3 of the movable holding member 20
4 continuously extends from the free end side to the base end side of the arm portion 24 in a rib shape on the clamp surface 16a, so that the side surface of the load 28 to be clamped, the second clamping surface 36a and the clamp surface 16a
The effect of improving the engagement effect with is provided.

When there is a step in the lateral shape of the stack of a plurality of loads 28 arranged side by side in the horizontal direction, when the load stack is sandwiched between the pair of clamp arms 16, the movable holding member 20 It automatically rotates along the curved wall surface 32 and causes the orientation of the first sandwiching surface 34a of both first portions 34 and the second sandwiching surface 36a of the second portion 36 to follow the side shape of the load stack. As a result, such irregular load accumulation bodies can be collectively clamped by the pair of clamp arms 16. This operation is effectively performed regardless of the rigidity of the load 28, that is, regardless of the magnitude of the holding force and the presence or absence of the bending of the clamp arm 16. Moreover, at this time, the clamping force applied to the clamp arm 16 is applied to the curved wall surface 3 of the arm portion 24.
2 can be received in a distributed manner, the durability of the arm portion 24 is improved, and as a result, an increase in the manufacturing cost of the clamp device can be suppressed.

Furthermore, when clamping the stack of the load 28 having relatively low rigidity, the clamp arm 16 has a gripping force that does not damage or deform the load 28 without bending the arm portion 24 itself. Aggregates can be clamped.
At this time, if the shape of the load 28 is uniform as shown in FIG. 2, the movable holding member 20 of each clamp arm 16 is pushed into the accommodation portion 30 on the free end side of the arm portion 24, and It automatically rotates along the curved wall surface 32 so as to be pushed out of the housing portion 30 at the base end side of the portion 24 (FIG. 4B). As a result, the first holding surface 34a of each of the first portions 34 of each movable holding member 20 and the second holding surface 36a of the second portion 36 are located on both the free end side and the base end side of the arm 24. Of the load stack, which is located on the side close to the clamp base 14,
Can be collectively clamped by the pair of clamp arms 16.

FIG. 6 shows one clamp arm 42 and three movable holding members 44 installed on the clamp surface 42a of the clamp arm 42 of the clamp device according to the second embodiment of the present invention. The clamp device according to the second embodiment arranges a pair of clamp arms 42 so as to be relatively movable so as to selectively approach and separate from each other. Except for the configuration of the clamp arm 42 and the movable holding member 44, the clamp device described above is used. Since it is the same as the clamp device 10 according to one embodiment, its illustration and description are omitted.

As shown in FIGS. 6 to 8, the clamp arm 42 includes an arm 46 having a clamp surface 42a and a pair of upper and lower rails 48 extending in a direction substantially perpendicular to the arm 46. Prepare together. The arm portion 46 of the clamp arm 42 is recessed in the clamp surface 42 a, and three accommodation portions 50 each accommodating the movable holding member 44, and each arm portion 46 is installed in each accommodation portion 50. And a support portion 52 for movably supporting the movable holding member 44.
Each of the accommodating portions 50 is separated from each other at substantially equal intervals in the vertical direction of the arm portion 46 and has a rectangular opening 50a extending from the free end region to the base end region of the arm portion 46 on the clamp surface 42a. Back side 42 opposite to 42a
Similarly, b is formed as a rectangular through hole.
Therefore, each accommodation section 50 is defined by the four inner wall surfaces 46b at the front and rear and up and down of the arm section 46.

The support section 52 is composed of a pair of cylindrical columns 52 fixedly arranged at predetermined positions in each of the accommodating sections 50. The cylindrical pillars 52 each have a central axis 52 a substantially perpendicular to the upper and lower end surfaces 46 a of the arm 46, and are dispersedly arranged on the free end side and the base end side of the arm section 46. Preferably, as shown in FIG. 7, each cylindrical support 52 has a length reaching the upper and lower end surfaces 46 a of the arm 46, and a plurality of holes 54 formed in the arm 46 so as to be aligned in the vertical direction. And is extended through all the accommodating parts 50. Further, each cylindrical support 52 can be constituted by a solid rod shown in FIG. 7 or a rotatable roller shown in FIG.

Each movable holding member 44 integrally includes a first portion 56 protrudable from the clamp surface 42 a of the arm portion 46 and a second portion 58 accommodating in the accommodating portion 50. The first portion 56 of the movable holding member 44 has a holding surface 56a that linearly extends in a direction in which the arm portion 46 extends at a position protruding from the clamp surface 42a. The second portion 58 of the movable holding member 44 is concealed in the housing portion 50 on the side opposite to the holding surface 56a, and is formed in an arc shape in the direction in which the arm portion 46 extends, and
It has a support surface 58a that protrudes to the side away from 6a. The support surface 58a of the second portion 58 is a part of a cylindrical surface having a predetermined curvature, and comes into contact with the support portion of the arm portion 46, that is, the outer peripheral surfaces of the pair of cylindrical supports 52.

The second portion 58 of each movable holding member 44 includes
A long hole 60 extending in an arc shape along the support surface 58a is formed between the upper end surface and the lower end surface. On the other hand, in each of the accommodating portions 50 of the arm portion 46, at a predetermined position between the pair of cylindrical posts 52, a cylindrical holding column 62 having a center axis 62a substantially perpendicular to both upper and lower end surfaces 46a of the arm portion 46 is provided. It is fixedly arranged. The holding column 62 includes the movable holding member 44.
Are slidably received in the long hole 60, and the upper end surface and the lower end surface of the movable holding member 44
b. Thereby, the movable holding member 44 is held so as not to drop off from the storage section 50 of the arm section 46 and to prevent rattling in the storage section 50. Preferably, as shown in FIG. 7, the holding column 62 has a length reaching the upper and lower end surfaces 46 a of the arm portion 46, and is provided in a plurality of holes 64 formed through the arm portion 46 in a vertically aligned manner. It is received and extends through all the accommodating parts 50.

In this state, each of the movable holding members 44 is brought into contact with the support surface 58a and the outer peripheral surfaces of the two cylindrical columns 52 of the arm portion 46, and to a cylindrical surface having a predetermined curvature around the center axis of the support surface 58a. Along the front and rear directions of the arm 46, the arm 46 can be rotated as shown by the arrow Q in the figure. Such a rotating operation of the movable holding member 44 is defined in a range until the holding column 62 collides with the front end or the rear end of the long hole 60 of the arm portion 46.

The clamp arm 42 having the above configuration is
It operates similarly to the clamp arm 16 of the clamp device 10 according to the first embodiment. That is, regardless of the rotational position of each movable holding member 44, the holding surface 56a of the first portion 56 is disposed so as to protrude from the clamp surface 42a of the arm 46 (FIG. 8). At this time, the first portion 5 of each movable holding member 44
6 continuously extends in a rib shape from the free end side to the base end side of the arm portion 46 on the clamp surface 42a, so that the function of improving the engagement between the side surface of the load to be clamped and the clamp surface 42a is achieved. .

When there is a step in the side shape of a plurality of loads stacked side by side in the horizontal direction, when the load stack is sandwiched by a pair of clamp arms 42, each movable holding member 44 The first portion 56 is automatically rotated individually along the two cylindrical supports 52 so that the orientation of the holding surface 56a of the first portion 56 follows the side shape of the load stack. As a result, such irregular load accumulation bodies can be collectively clamped by the pair of clamp arms 42. In this case, the three movable holding members 44 are arranged at substantially equal intervals in the vertical direction of the arm portion 46 and can be independently rotated in each of the housing portions 50, so that they are not aligned in the height direction. There is an advantage that a load accumulation body can be stably held. This operation is effectively performed regardless of the rigidity of the load, that is, regardless of the magnitude of the holding force and the presence or absence of the bending of the clamp arm 42. In particular, the cylindrical support 5
By further increasing the number of 2, the holding force applied to the clamp arm 42 can be dispersedly received by the cylindrical columns 52, so that the durability of the arm portion 46 is improved, and as a result, the manufacturing cost of the clamp device is reduced. The rise can be suppressed.

Further, when holding the load stack having relatively low rigidity, the load stack is bent without bending the arm 46 itself with a holding force that does not cause the clamp arms 42 to damage or deform the load. Can be pinched. At this time,
If the shape of the load is uniform, each movable holding member 44 of each clamp arm 42 is
At the same time as it is pushed into the cylinder 0, it automatically rotates along the two cylindrical columns 52 so as to be pushed out of the housing 50 on the base end side of the arm 46. As a result, each movable holding member 44
Of the first portion 56 is engaged with the side surface of the load accumulator on both the free end side and the proximal end side of the arm portion 46. Can be collectively clamped by the pair of clamp arms 42, including the load arranged in the first position.

Although the present invention has been described based on the preferred embodiment, the present invention is not limited to this, and various other modifications and variations are possible. For example, the clamping device 1 of FIG.
At 0, the curved wall surface 32 of the arm portion 24 may be formed in a concave shape, and the support surface 36b of the movable holding member 20 may be formed in a convex shape. Similarly, in the clamp arm 42 shown in FIG.
Can be formed in a concave shape.

In the clamp device 10 of FIG. 1, the movable holding member 20 mounted on the clamp arm 16 is
Similarly to the movable holding member 44, the arm portion 24 can be structurally and functionally divided into a plurality in the vertical direction.
Further, in the clamp arm 42 shown in FIG. 6, the number of the movable holding members 44 can be further increased, or the movable holding members 2 shown in FIG.
It can also be integrated like 0.

In any of the above embodiments, the first holding surface 34a of the movable holding member 20 and the movable holding member 4
The holding surface 56a of No. 4 has a shape that extends linearly and continuously between the base end regions and the free regions of the arm portions 24 and 46, but employs a surface that extends in, for example, a wavy shape, an uneven shape, or a step shape. You can also.

As shown in FIG. 9, in the clamp device 10 of FIG. 1, the movable holding member 20 mounted on the clamp arm 16 is structurally and functionally divided into a plurality in the direction in which the arm portion 24 extends. You can also. In this case, the arm portion 24 serves as a support portion disposed in the accommodating portion 30, and has three curved wall surfaces extending intermittently in an arc shape in the extending direction of the arm portion 24 and in a convex shape toward the rectangular opening 30 a side. 70. Then, three movable holding members 72 having a support surface 72b having substantially the same curvature as each curved wall surface 70
Are accommodated in the accommodating portion 30 side by side in the extending direction of the arm portion 24. Each of the movable holding members 72 has substantially the same configuration as that of the movable holding member 20, and the support surface 72 b thereof comes into uniform contact with each curved wall surface 70 and slidingly engages. It will be understood that such a configuration provides the same operation and effect as the clamp arm 16 in the clamp device 10 of FIG.

As shown in FIG. 10, in the clamp arm 42 shown in FIG. 6, a plurality of compression springs 74 are used in place of the cylindrical support 52 as a support disposed in the accommodating portion 50 of the arm 46. You can also. In this case, the arm 46 has a wall surface 76 that supports the compression spring 74 and the support surface 58 a of the movable holding member 44 in the housing 50. According to such a configuration, since the compression spring 74 holds the movable holding member 44 so as not to fall out of the housing portion 50, the pressing column 62 and the elongated hole 60 of the movable holding member 44 in the clamp arm 42 in FIG. become.

[0040]

As is apparent from the above description, according to the present invention, the distance between the clamp surfaces of the pair of arms is designed to be smaller at the free end side than at the base end side under no load. In the clamping device, even when the rigidity of the object to be clamped is relatively weak, the clamping force is such that it does not damage or deform the object, and the object is clamped at both the free end side portion and the base end side of both arms. An object can be reliably held. In addition, the support surface of the movable holding member, which is movably supported by the support portion of the arm, is formed in an arc shape, so that the holding force applied to the arm can be dispersedly supported by the support portion, thereby improving the durability of the arm. In addition, the structure for supporting the movable holding member can be simplified, and as a result, an increase in the manufacturing cost of the clamp device can be suppressed.

[Brief description of the drawings]

FIG. 1 is a perspective view of a clamp device according to a first embodiment of the present invention.

FIG. 2 is a plan view of the clamp device of FIG.

FIG. 3 is an exploded perspective view of one clamp arm of the clamp device of FIG. 1;

FIGS. 4A and 4B are cross-sectional views of the arm portion of the clamp arm of FIG. 1 taken along line IV-IV, in which (a) the movable holding member is shown at one rotation position, and (b) the movable holding member is rotated differently. It is a figure shown by a movement position.

FIG. 5 is a cross-sectional view of the arm portion of the clamp arm of FIG. 1 taken along line VV.

FIG. 6 is a perspective view of one clamp arm of the clamp device according to the second embodiment of the present invention.

FIG. 7 is an exploded perspective view of the clamp arm of FIG. 6;

8 is a line VIII-VI of the arm portion of the clamp arm of FIG.
FIG. 2 is a cross-sectional view along II.

FIG. 9 is a sectional view showing a modification of the arm portion of the clamp arm of FIG.

FIG. 10 is a sectional view showing a modification of the arm portion of the clamp arm of FIG.

[Explanation of symbols]

 14 Clamp base 16, 42 Clamp arm 20, 44, 72 Movable holding member 24, 46 Arm part 30, 50 ... Housing part 32, 70 ... Curved wall surface 34a ... First holding surface 36a ... Second holding surface 36b , 58a, 72b ... support surface 40 ... holding plate 52 ... cylindrical support 56a ... holding surface 62 ... holding support

Claims (5)

[Claims] 1. A base, a pair of arms extending in substantially the same direction with respect to the base, facing each other, and relatively movable to approach and separate from each other, and each of the arms is installed on a mutually facing surface of the arms. A clamping device comprising: a movable holding member; and a pair of arms, each of the pair of arms being recessed in the mutually facing surfaces, and a housing portion for housing the movable holding member; A support portion movably supporting a member, wherein the movable holding member includes a holding surface extending in a direction in which the pair of arms extend in a direction in which the arms extend at a position protruding from the mutually opposing surfaces; And a support surface extending in an arc shape in a direction in which the arm extends in the portion and engaging with the support portion. 2. The support surface of the movable holding member comprises a part of a cylindrical surface, and the support portion of the arm has the same curvature as the support surface and extends in a direction in which the arm extends. The clamping device according to claim 1, comprising a curved wall surface that uniformly contacts the support surface. 3. The extension of the arm, wherein the support surface of the movable holding member comprises a part of a cylindrical surface, and the support portion of the arm has a center axis parallel to a center axis of the support surface. The clamping device according to claim 1, comprising a plurality of cylindrical posts distributed in the direction. 4. The holding surface of the movable holding member extends continuously between a base region of the arm adjacent to the base and a terminal region of the arm away from the base. The clamp device according to any one of the above. 5. The clamp device according to claim 1, wherein a plurality of the movable holding members are provided on each of the pair of arms.