JPS63312041A - Parallel clamp device - Google Patents

Abstract

PURPOSE:To hold a clamping force only with a mechanical means by fixing a first coupling member fitting one end closely in a groove of a sliding piece to a first clamping member and a second coupling member provided with an engaging portion fitting in said groove to a drive unit. CONSTITUTION:When a drive force of a drive unit 5 is shut off while an article is clamped by first and second clamp members 11, 21, the drive unit 5 becomes unmovable so that metal balls 7 are urged by a spring 8 toward the tapered surface 63 of a sliding piece 6 to frictionally engage firmly with the surface of a drive shaft 2 with a wedge effect. Thus, the first clamp member 11 will frictionally engage the drive shaft 2 through the first coupling member 16 and sliding piece 6 to block the first clamp member 11 from movement. Thus, the movement of the second clamp member 21 is also blocked to hold an article without reducing a clamping force. Thus, the clamping force of clamp can be maintained only with a mechanical means without needing any compressed air or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a parallel clamp device that grips an article by expanding or contracting the distance between a pair of parallel clamps using a fluid drive means or the like.

[Prior Art] In workpiece supply and conveyance devices, for example, a parallel clamp device as shown in Fig. 6 is used to grasp the workpiece and release it after it has been moved to a predetermined location. .

A rack part 101 is formed in the middle part of the piston 1.
Clamps 104 are fixed to one end of each of a pair of sliding shafts 103 to which 02 is attached, and these clamps 104 are arranged in parallel so that they face each other and are connected to rack parts 101 via pinions 105.

Then, the pinion 105 is pivotally supported in a case 106, and compressed air is supplied into the case 106 to drive the piston 102, so that it slides on the sliding shaft 103, and the gap between both clamps is expanded or reduced. Thus, it is possible to clamp or release objects such as workpieces.

[Problems to be Solved by the Invention] However, in the above-mentioned parallel clamp device, it is necessary that compressed air is supplied at least while the article is being gripped; When it disappears, the gripping force between both clamps disappears. Therefore, if the supply of compressed air is cut off while a workpiece or the like is being held between both clamps, the workpiece or the like will fall from that position.

Therefore, in such a parallel clamp device, it has been desired that the gripping force of the clamp be maintained even when the supply of compressed air is cut off when a workpiece or the like is being clamped.

On the other hand, as a braking mechanism for a piston rod used in welding robots, etc., a wedge member or a steel ball biased by a spring is installed opposite the piston rod, and compressed air is always supplied to offset the biasing force. It is known that during braking, compressed air is discharged, steel balls are pressed against the piston rod, and the movement of the piston rod is stopped by the frictional force of the steel balls.

Therefore, if this brake mechanism is installed on the sliding shaft of the parallel clamp device, the compressed air of this brake mechanism can be discharged when compressed air is not supplied to the piston that drives the sliding shaft, and the clamp can be gripped easily. It becomes possible to prevent loss of power.

However, even if the brake mechanism described above is adopted, compressed air must still be used, and a compressed air passage, a valve device, and a control means must be added, resulting in a complicated configuration. Furthermore, if the parallel clamp device is driven by an electric motor or the like, a separate compressed air supply means must be provided just for the brake mechanism.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a parallel clamp device equipped with a mechanism that can maintain the clamping force using only mechanical means without requiring compressed air or the like.

[Means for Solving the Problems] In order to solve the above problems, the present invention employs the following configuration.

That is, the drive shaft, the first sliding shaft, and the second sliding shaft are installed in parallel with each other, and includes a bearing plate supporting a pinion, a drive unit slidably attached to the drive shaft, and a first rack. A first clamp member slidably attached to at least a first sliding shaft, and a second rack connected to a first rack of the first clamp member via a pinion are connected to at least a second sliding shaft. a second clamp member slidably attached to the cylinder; and a cylinder into which the drive shaft is inserted while maintaining a gap with the inner cylinder surface, the outer cylinder surface having a groove of a predetermined width substantially perpendicular to the drive shaft. The slider is pressed in the direction of the drive unit by the urging force of the urging means, which is interposed in the gap between the inner cylindrical surface of the slider and the surface of the drive shaft and whose one end is locked to the slider. An engagement member that frictionally engages the slider and the drive shaft has a width that is approximately the same as the axial distance between the engagement member and the drive unit, and a width between the inner cylindrical surface of the slider and the drive shaft. It is provided with a loose fit that fits between the surface and the surface.

A first coupling member whose one end is closely fitted into the groove of the slider is fixed to the first clamp member, and a member whose one end is fitted into the groove of the slider with a predetermined interval maintained in the axial direction of the drive shaft. An axial direction in which a gap smaller than the distance between the other side of the groove and the engagement part is formed between the slider and the drive unit when the engagement part is engaged with one side of the groove. A second coupling member having a distance is fixed to the drive unit.

[Operation] In such a parallel clamp device, when the drive unit is driven to slide on the drive shaft, the first clamp member connected by the first coupling member slides on the first sliding shaft. move.

At this time, the first clamp member and the second clamp member are each provided with a rack, and these racks are connected via a pinion supported on a bearing plate, so that the second clamp member and the first clamp member are opposite to each other. direction on the second sliding shaft.

Therefore, the first clamp member and the second clamp member move closer to each other or move away from each other depending on the direction of movement of the drive unit, and when they approach, they grip an article such as a workpiece, and when they move apart, they release it.

On the other hand, since the slider attached to the drive shaft is coupled to the drive unit by the second coupling member having a retaining portion that fits into the groove on the outer cylinder surface, for example, the drive unit is connected to the first clamp member. When the second clamp member is moved in the direction toward which the second clamp member approaches, the retaining portion abuts one side of the groove of the slider and moves the slider in the same direction as the drive unit. Therefore,
The retaining member also moves in the same direction.

At this time, the driving force of the drive unit is not directly transmitted to the loose fitting fitted between the slider and the sliding shaft, and it remains in that position and relatively pushes the engagement member against the urging force. Since the shaft is pressed by the shaft, no frictional engagement occurs between the shaft and the drive shaft.

If the driving force of the drive unit is cut off in this state, that is, the state where the article is being gripped by the first and second clamp members, the engagement member will be loosely engaged by the biasing force since the drive unit will no longer move. while pushing it toward the drive unit, and press between the inner surface of the slider and the surface of the sliding shaft. Therefore, the first clamp member is frictionally engaged with the drive shaft via the first coupling member and the slider, and the movement of the first clamp member and therefore the movement of the second clamp member is also prevented, and the gripping The article is held without any loss of force.

When the drive unit is moved in the opposite direction from this state, the drive unit presses the slider and the loose fit, causing the loose fit to contact the retaining member and resisting the urging force of the urging means. The slider is moved in the direction away from the drive unit to release the frictional engagement, so the slider moves in the same direction, and the first clamp member and the second clamp member move to widen the space between them. .

[Embodiments] Preferred embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show one embodiment of the present invention, FIG. 4 is an exploded perspective view thereof, and FIGS. 5(a) to 5(c) are explanatory views of the operation.

First, as is clear from FIGS. 2 and 3, a drive shaft 2, a first sliding shaft 10, and a second sliding shaft 20 are mounted on a pair of opposing bearing plates 1.

As is clear from FIGS. 1 and 2, a pinion bracket 3 is installed on the bearing plate 1, and a pinion 4 is pivotally supported by a pin 41 in the center thereof. A drive unit 5 is slidably mounted on the drive shaft 2.

In this embodiment, the sliding unit 5 has a piston (not shown) fixed to the drive shaft 2, and a compressed air boat 51 is provided in a piston chamber formed between the piston and the inside of the drive unit 5.
．． The drive unit 5 is moved from side to side in FIG. 1 by supplying and discharging compressed air, and conversely discharging and supplying compressed air through the compressor 52.

The drive unit 5 may be one that uses an electric motor as a drive source and slides on the drive shaft 2 via a gear mechanism, and there are various types of drive units.

As is clear from FIGS. 1 and 3, the slider 1 of the first clamp member 11 is attached to the first sliding shaft 10 and the second sliding shaft 20.
2 and the slider 22 of the second clamp member 21 are slidably arranged symmetrically about the pinion 4.

The sliders 12 and 22 are both slidably fitted to both the first and second sliding shafts 10 and 20, but the slider 12 is fitted only to the first sliding shaft 10, and the slider 22 is fitted to the second sliding shaft 10. It may be slidably fitted only to the sliding shaft 20.

These sliders 12 and 22 each have a first rack 1
4 and a second rack 24 are fixed, and the first rack 14, pinion 4, and second rack 24 are in mesh with each other (FIG. 3).

Further, a first coupling member 16 having a U-shaped receiving portion is fixed to the slider 12 (FIGS. 2 and 3).

In FIG. 1, an attachment 15 is fixed to the slider 12 via a bracket 13, and the first clamp member 1
1 is formed, an attachment 25 is fixed to the slider 22 via a bracket 23, and a second clamp member 2 is formed.
1 is formed.

A cylindrical slider 6 is fitted onto the drive shaft 2 while maintaining a gap with the inner cylindrical surface 62, and a loose fit 9 is arranged in a ring shape around the drive shaft 2 in this gap. A metal ball 7, a ring plate 81, a collar 82, a retaining ring 83, and a tensioned spring 8 are inserted between the ring plate 81 and the collar 82.

Note that the retaining ring 83 is locked in an annular groove formed in the inner cylindrical surface 62 of the slider 6.

A tapered surface 63 is formed on the inner cylindrical surface 62 of the slider 6, and a metal ball 7 is formed between this tapered surface 63 and the surface of the drive shaft 2.
In FIG. 1 with the drive unit 5 in a stopped state, the metal ball 7 is biased by the spring 8 in a direction that narrows the distance between the tapered surface 63 and the surface of the drive shaft 2, creating a so-called wedge effect. As a result, the slider 6 and the drive shaft 2 are frictionally engaged.

In this embodiment, the engaging member referred to in the present invention is constituted by a metal ball 7, and the biasing means is constituted by a spring 8.

Although not shown in the drawings, this type of engagement member includes a wedge-shaped slider, one end of which is rotatably fixed to the inner surface of the slider 6, and the other end of which is provided with a lever that supports a roller. In some pistons, a piston having a surface is biased by a spring and presses the tapered surface against the roller of the lever, thereby frictionally engaging the lever with the drive shaft 2 on the principle of leverage.

As shown in FIG. 1, the loose fitter 9 has a cylindrical shape with approximately the same height as the distance between the metal ball 7 and the drive unit 5, and is slidably attached to the drive shaft 2 via a bush 30. , can also freely slide on the cylindrical surface 62 of the slider 6, and according to the movement of the slider 6, the metal ball 7 is moved against the spring 8 to form a shoulder formed by the tapered surface 63 and the cylindrical surface 62. It is configured to be pressed until it comes into contact with 64.

A groove 61 is formed in an annular shape with a predetermined width on the outer peripheral surface of the slider 6, and a second coupling is formed by halving a cylindrical body in the axial direction and having an engaging portion 27 narrower than the groove 61. A member 26 is fixed to the axial end face of the drive unit 5. When the engaging portion 27 is brought into contact with one side surface of the groove 61 of the slider 6 and fitted, the gap formed between the groove 61 and the other side surface corresponds to the sliding distance between the drive unit 5 and the slider 6. The axial length of the second coupling member 26 is determined so as to be larger than the gap formed between the second coupling member 26 and the child 6.

That is, when the drive unit 5 moves to the right in FIG. 1, the engaging portion 27 does not come into contact with the groove 61, but the axial end surface of the drive unit 5 and the axial end surface of the slider 6 come into contact. It is formed.

Further, a U-shaped receiving portion of a first coupling member 16 fixed to the slider 12 is tightly fitted into the groove 61 of the slider 6, and thus the first clamp member 11 is tightly fitted with the slider 6. They move almost integrally (Fig. 2, Fig. 3).

FIG. 4 shows an example of the above-mentioned parallel clamp device disassembled into component parts, and parts whose explanation is omitted in FIGS. 1 to 3 include a bush 42 and a liner 43 that are assembled to the pinion 4. , side plates 17 and 18, and a bushing 30 attached to the sliding portion of the sliding shaft.

The operation of the embodiment configured as above will be explained.

FIG. 1 shows a state in which the drive unit 5 is stationary as described above, and at this time the slider 6 is in frictional engagement with the drive shaft 2 and therefore does not slide, so that the first clamp member 11 and the second Clamp member 21 does not slide. When the drive unit 5 is driven from this state and moves to the left in FIG. move it. Then, Yukinako 9
is able to slide on the slider 6 and will remain as it is, so it will relatively press the metal ball 7 held between the tapered surface 63 and the surface of the drive shaft 2, and the tapered surface 6
3 also moves to the left in FIG. 1 due to the movement of the slider 6, and moves in a direction that reduces the frictional force between the metal ball 7 and the drive shaft 2. Therefore, the frictional force between the metal ball 7 and the drive shaft 2 also decreases, and eventually the sliding occurs. The frictional engagement between the slider 6 and the drive shaft 2 is released, and the slider 6 and the first
The first clamp member 11 connected by the connecting member moves to the left in FIG.

The operating state of the slider 6 as described above is shown in FIG. and color 8
2 shows the moving state.

In FIGS. 1 and 3, when the slider 12 of the first clamp member 11 moves to the left in the drawings, the first rack 14, bracket 13, and attachment 15 fixed thereto also move to the left. The second rack 24 is connected to the first rack 14 via the pinion 4.
moves to the right in the figure.

Therefore, the slider 22 to which the second rack 24 is fixed moves rightward, and the bracket 23 and attachment 25 fixed thereto also move rightward.

Thus, the attachments 15 and 25 are brought close together, and a necessary article (not shown) can be held between them.

In this state, if the driving force of the drive unit 5 is lost due to, for example, a blockage of the compressed air passage, the force between the first and second clamp members 11 and 12 will be applied as a component of the gravity of the gripped article. A force will act in the direction of expansion.

That is, the slider 6 connected by the first connecting member 16 has the first
A force is applied in the right direction in the figure.

At this time, since the drive unit 5 is stopped, the engaging portion 27 of the second coupling member 26 is in a state of being engaged with the side surface of the groove 61 of the slider 6, and the loose fit 9 is in contact with the drive unit 5. It appears that they are placed in close contact with each other.

Therefore, the metal ball 7 is biased by the spring 8 in the direction of the tapered surface 63 of the slider 6, that is, in the left direction in FIG. 1, and this biasing force causes the slider 6 to move in the right direction in FIG. Due to the combination of these forces, the metal ball 7 is pressed between the lower surface 63 and the surface of the drive shaft 2, resulting in a strong frictional engagement between them due to a so-called wedge effect, and the first clamp member 11 and the first clamp member 11 are pressed against each other. The two clamp members 21 are prevented from moving in the expansion direction, and the gripped component is held between the two clamp members.

FIG. 5(b) shows the relationship of the slider 6, etc. in this state.

Next, the operation when moving the first and second clamping members 11.21 in the direction of spreading out in order to release the held article, that is, when moving the drive unit 5 to the right in FIG. 1, will be described.

The operation of the sliders 12, 22, etc. in this case is the same except that they move in the opposite direction to the previously described operation. Therefore, the operation of the slider 6 and the like will be explained with reference to FIG. 5(c).

In FIG. 5(c), when the drive unit 5 moves in the direction of the white arrow from the state shown in FIG. It comes into contact with child 9.

That is, the distance between the drive unit 5 and both end faces of the slider 60 when the drive unit 5 is stationary (S in FIG. 5(b)) is equal to the width of the groove 61 and the axis of the retaining portion 2 of the second coupling member 26. Since it is set to a value smaller than the difference in length in the direction (Fig. 5 (b)),
The engaging portion 2 is spaced apart from one side of the groove 61, and the both end surfaces abut before coming into contact with the other side.

Therefore, the loose fitter 9 moves relative to the slider 6 by the distance between the end surfaces of the drive unit 5 and the slider 6 when the drive unit 5 is at rest. Then, the loose fitter 9 comes into contact with the metal ball 7 and moves the metal ball 7 to the right in FIG. 5(c) against the biasing force of the spring 8.
The frictional engagement between the slider 6 and the drive shaft 2 via the slider 6 is released, and the slider 6 moves as the drive unit 5 moves in the right direction. In the present invention, the slider is attached to the drive shaft, but it is also possible to attach the slider to the first sliding shaft and connect the two by fixing the first coupling member to the drive unit. The drive unit and the first clamp member may be reversible with respect to the slider.

[Effects of the Invention] As described above, according to the present invention, the first clamp member and the second clamp member are moved and stopped in accordance with the movement and stop of the drive unit on the drive shaft to grip and release the article. When the drive unit is stopped, the first clamp member and the second clamp member can be reliably held in the stopped position by the frictional engagement between the drive shaft and the slider by the engagement member, and the sheet metal drive Even if the drive signal to the unit is cut off, the gripped article can be maintained in a clamped state.

Moreover, even if the size of the gripped article varies and the distance between the first clamp member and the second clamp member varies, the clamped state can be maintained when stopped, and furthermore, the clamped state can be maintained. There is no need for a driving source such as compressed air for this purpose, and a stable clamping condition can therefore be ensured.

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional view from the front showing an embodiment of the parallel clamp device of the present invention; FIG. 2 is a partial cross-sectional view from the side; FIG. 3 is a partial cross-sectional view from the top; FIG. 4 is an exploded perspective view of an embodiment of the present invention, and FIG. 5(a)
5(c) are explanatory diagrams of the operation in one embodiment of the present invention, FIG. 5(a) is an explanatory diagram when the drive unit moves to the left in the figure, and FIG. 5(b) is an explanatory diagram of the drive unit. FIG. 5(C) is an explanatory diagram when the drive unit is moved to the right in the figure. FIG. 6 is a cross-sectional view of a conventional parallel clamp device. 1...Bearing plate, 2...Drive shaft, 4-...Pinion 5
... Drive unit 6 ... Slider 7 ... Metal ball, 8 ... Spring (biasing means) 9.
... Loose fitting, 10... First sliding shaft 11... First clamp member, 14... First rack 16... First
Coupling member, 20--Second sliding shaft 21...Second clamp member, 24...Second rack 26...Second coupling member, 27...Engaging portion 61...Groove Agent Patent Attorney Makoto Ikeda No. 2, No. 3121 5th (a) 5th (b)

Claims (2)

[Claims] (1) A drive shaft, a first sliding shaft, and a second sliding shaft installed in parallel to each other, a bearing plate supporting a pinion, a drive unit slidably attached to the drive shaft, and a first rack. a first clamp member slidably attached to at least the first sliding shaft; and a second rack connected to the first rack of the first clamp member via the pinion. a second clamp member slidably attached to a second sliding shaft; and a cylindrical body through which the drive shaft is inserted while maintaining a gap with the inner cylinder surface, and a predetermined portion substantially perpendicular to the drive shaft on the outer cylinder surface. a slider formed with a wide groove; and a biasing force of a biasing means interposed in a gap between the inner cylindrical surface of the slider and the surface of the drive shaft and having one end locked to the slider. an engaging member that is pressed in the direction of the drive unit and frictionally engages the slider and the drive shaft, and has a width that is approximately the same as the axial distance between the engagement member and the drive unit. a first coupling member comprising a loose fit that fits between the two and between the inner cylindrical surface of the slider and the surface of the drive shaft, and one end of which fits closely into the groove of the slider; an engaging portion that is fixed to the first clamp member and that fits into the groove of the slider while maintaining a predetermined interval in the axial direction of the drive shaft; the engaging portion that engages with one side of the groove; Driving the second coupling member having an axial distance such that a gap smaller than a gap between the other side of the groove and the engaging portion is formed between the slider and the drive unit when the slider and the drive unit are mated together. A parallel clamp device characterized by being fixed to a unit. (2) A tapered surface whose inner diameter decreases toward the drive unit is formed on the inner cylindrical surface of the slider, and the engaging member is arranged between the tapered surface and the surface of the drive shaft. Both of them are composed of one metal ball, and the biasing means is composed of a spring that has one end latched to the inner cylindrical surface of the slider and the other end that presses the metal ball. Parallel clamping device according to scope 1.