JPH0539837Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention functions to position and hold one or both workpieces in a predetermined position when performing welding or other processing on a panel-shaped workpiece, for example. In particular, by using a floating structure for the clamping claws, even if the part of the workpiece clamped by the clamping claws is positioned at an angle with respect to the clamping surface of the clamping claws, the workpiece clamping device can be used. The present invention relates to a floating type clamp device that can adequately clamp a workpiece without actively changing the posture of the claws using an actuator.

(Prior Art) As a conventionally known workpiece clamping device, there is one shown in FIGS. 5a and 5b, for example.

In the device shown in FIG. 5a, 1 indicates a fixed clamp claw, 2 indicates a movable clamp claw, and
These two pieces form a pair.

Here, the fixed clamp claw 1 is supported by a bearing portion 4 provided at the tip of the reciprocating rod 3, and can rotate around three axes of the orthogonal coordinate system, and the movable clamp claw 2 has an intermediate portion pivotally supported by an arm 5 protruding from the fixed clamp claw 1, and can swing relative to the fixed clamp claw 1 in the opening/closing direction.

Here, the bearing portion 4 of the fixed clamp claw 1
The rotational movement around the three axes is performed by three servo motors 6,
By attaching 7 and 8 to the bearing part 4, the swinging motion of the movable clamp claw 2 in the opening and closing direction is
Each is provided by connecting the rod of the cylinder 9 attached to the fixed clamping pawl 1 to the rear end of the movable clamping pawl 2.

According to such a workpiece clamping device, when positioning and holding the curved clamping portion C of a workpiece supplied by a robot or the like as shown by the imaginary line in the figure using, for example, two devices, each Activate the forward/backward rod 3 to bring both clamp claws 1, 2 to the desired forward/backward position,
By operating the three servo motors 6, 7, and 8, the clamp claws 1 and 2 are positioned across the workpiece clamping portion C in exact correspondence with the thickness direction thereof, and then the cylinder By the closing movement of the movable clamp claw 2 based on the operation of 9, the clamp portion C is sandwiched between both clamp claws.

The conventional device shown in FIG. 5b has a bracket 10 directly supported by a bearing 4, and two pairs of clamp claws 1 and 2 facing in the same direction are attached to the bracket 10. In order to appropriately clamp the inclined clamp portion _C1 as shown by the imaginary line in the figure from the thickness direction using such a device, it is necessary to operate the reciprocating rod 3 and the servo motors 6 and 7. In addition, the servo motor 8 is operated to rotate each pair of clamp claws 1 and 2.
is accurately positioned in the thickness direction of the clamp portion C ₁ , the movable clamp claw 2 is brought into close operation.

As described above, according to these conventional devices, the pair of clamp claws 1 and 2 are moved to a desired position by, in particular, three servo motors 6, 7, and 8, thereby bending or tilting the clamp claws. The work clamp parts C, _C1 can be properly held in the thickness direction by the respective pairs of clamp claws 1, 2.

(Problem to be Solved by the Invention) However, in this conventional technique, the entire rotational movement of the clamp claws 1 and 2 within the three-dimensional coordinate system is performed by the servo motors 6, 7, and 8. Since the process is carried out over a long period of time, there are problems in that the structure of the device becomes complicated and the cost of the device increases.

This idea was made by focusing on the problems of the prior art, and by simply providing two actuators, the rotational movement of a pair of clamp claws around each axis of a three-dimensional coordinate system can be achieved. The object of the present invention is to provide a floating type work clamp device that can simplify the structure of the device and reduce the cost of the device.

(Means for solving the problem) The floating type work clamp device of this invention is attached to a base plate protruding from a bearing portion and a swinging lever connected to this base plate, and positioned opposite to each other. A plurality of pairs of clamp claws on the fixed side and a movable side are provided, and an actuator is provided for opening and closing the clamp claws on the movable side via a swing lever.
When a plurality of other actuators that change the posture relative to the workpiece are provided, each of the pair of clamp claws is attached to a mounting bracket provided on each of the base plate and the swing lever in a direction perpendicular to the hinge pin of the swing lever. The levers are pivotably supported by an extending hinge pin so as to be able to swing within the same plane in a direction perpendicular to the swinging surface of the swinging lever, and the clamp claws are moved to a neutral position by elastic means. In addition, an actuator is provided that rotates the pair of clamp claws in a plane that includes the swing surface of the swing lever, and the claws are rotated along the axis of the base plate protruding from the bearing portion or an axis parallel thereto. Another actuator is provided for rotation around the .

(Function) According to this device, the pair of clamp claws can swing in the same plane against the pressing force of the elastic means, so that the curved or inclined workpiece clamp portion can be moved between the two clamp claws. When holding the workpiece with the clamping claws, the clamping part of the workpiece is located between the two clamping claws, and the clamping claws in the neutral position are closed under the action of the elastic means. Then, by swinging the clamp claw in contact with the work clamp part against the pressing force of the elastic means,
With both of these clamp claws, the workpiece clamping portion can be accurately clamped from the direction of its thickness.

Therefore, here, it is no longer necessary to swing the clamp claw in advance in a direction corresponding to the curve or inclination of the workpiece clamp portion, and furthermore, it is not necessary to provide an actuator for this purpose, and the structure of the device is made sufficiently simple. At the same time, the equipment cost and maintenance man-hours can be greatly reduced, and furthermore, the takt time can be advantageously shortened.

(Example) An example of this invention will be described below based on the drawings.

FIG. 1 is a diagram showing an embodiment of this invention.
In the figure, reference numerals 21 and 22 indicate a pair of fixed-side clamp claws and a movable-side clamp claw, respectively.

Here, the clamp claw 21 on the fixed side has a clevis-shaped mounting bracket 24 provided at the tip of the base plate 23, and this mounting bracket 24
, the clamp claw 21 is fixed by the hinge pin 25.
It is attached so that it can swing in a horizontal plane by pivoting the clamp claw 2 on the movable side
2, an arm 26 protruding forward from the base plate 23 supports an intermediate portion of a swinging lever 27, and a mounting bracket 28 also in the shape of a clevis is provided at the upper end of the swinging lever 27.
In addition, it is pivotally supported by a hinge pin 29 facing in a direction perpendicular to the hinge pin of the swing lever 27, so that it can swing in a horizontal plane including the clamp claw 21.

In addition, as shown in the enlarged plan view of the main part in FIG. 1b, the respective mounting brackets 24 and 28 are
Elastic means 30 and 31, which can be leaf springs, are respectively attached to both sides of the clamp claw 2.
1, 22, usually each clamping pawl 21, 22 is under the action of a respective elastic means 30, 31, both of which have an equal spring force.
Position it in a neutral position.

Furthermore, here, the base plate 23 is attached to the bearing part 32, and the hinge pins 2 of the clamp claws 21 and 22 are attached to the bearing part 32.
5 and 29, or around two axes parallel to them, and the swinging movement of one of them, in the figure, the swinging movement of the tip of the base plate in the vertical direction, By one servo motor 33 provided in the bearing part 32, and
The other oscillating motion, in other words, the oscillating motion of the base plate 23 around its central axis or an axis parallel thereto is brought about by the other servo motor 34 provided in the bearing portion 32. .

In addition, in the illustrated example, by attaching the cylinder 35 to the base plate 23 and connecting its piston rod 35a to the lower end of the swinging lever 27, the clamp claws 21, 22 can be closed based on the forward and backward movement of the piston rod 35a. Ensures opening operation.

In addition, numeral 36 in the figure indicates a reciprocating rod having a bearing portion 32 at its tip.

Fig. 2 shows the workpiece being clamped at an inclined portion C ₁ by two workpiece clamping devices as described above.
FIG. 2 is a plan view showing a case in which the inclined clamp portion C ₁ is held at an angle θ with respect to the neutral position of the clamp claws 21 and 22. FIG.

Here, in order to bring about the holding state as shown in the figure, first, by operating the two servo motors 33 and 34 and the forward/backward rod 36 for each device, the clamp claw 21 in the released state,
22 are positioned so that each of the clamping claws 21, 22 is located across the inclined clamping portion _C1 , and then the clamping claws 21, 22 are fed between the clamping claws,
Alternatively, the clamp claws 21 and 22 are operated to close under the action of the cylinder 35 with respect to the workpiece that exists between the clamp claws in advance.

According to this, each elastic means 30,
The respective clamping pawls 21 _, 22, initially in a neutral position, energized by around, counterclockwise in the figure, elastic means 30, 31
The clamp claws 21 and 22 approach each other while swinging against the spring force, and when the swing angle becomes equal to the tilt angle θ of the inclined clamp portion _C1 , Between them, the inclined clamp part
Securely clamp C ₁ from its thickness direction as shown.

Therefore, here, based on the swinging movement of the clamp claws 21 and 22 within the same plane, the clamp claws 2
1 and 22 by the inclination angle θ of the inclined clamp portion C ₁ by the actuator, in other words, the line segment connecting the respective hinge pins 25 and 29 is perpendicular to the inclined clamp portion C _{1 .} The inclined clamp portion C ₁ can always be clamped from its thickness direction without causing a clamping claw posture that intersects with the clamping claw posture, and the installation of an actuator for such a swinging movement of the clamping claws 21 and 22 is necessary. becomes unnecessary.

The same applies to the case of holding a curved clamp part of a workpiece. In this case, by making the clamp width of the clamp claws 21 and 22 sufficiently small, the curved clamp part can be held. A clamp that is properly oriented in the thickness direction can be realized.

FIG. 3 is a diagram showing an example of application of the device described in _FIG . By clamping from this direction, even if there is an inclined part in the vertical direction at the clamp position, the clamp claws 21,
Based on the rocking motion of 22, the flange portion _A1 can be reliably clamped from its thickness direction.

FIG. 4 is a perspective view showing another embodiment of this invention. In this example, the base plate 23 attached to the bearing part 32 is constructed so that the planar shape is approximately U-shaped.
Clamp claws 21, 22, a cylinder 35, and the like are attached to each end of the servo motors 33, 34 and one retractable motor in the same manner as in the previous example. Two pairs of clamp claws 21 and 22 are secured by the rod 36.
, and here again each pair of clamping pawls 2
1 and 22 can swing within the same plane, there is no need for an actuator for swinging the clamp claws 21 and 22 around their swing axes or around an axis parallel to the swing axes.

(Effect of the invention) Thus, according to this invention, in particular, each of the pair of clamp claws is attached to the mounting bracket,
Both clamps are pivoted so that they can swing in the same plane and are biased to a neutral position by elastic means, so that when clamping a curved or inclined clamp part of a workpiece with these clamp claws, both clamps Because the claws themselves clamp the clamp portion from the thickness direction by their oscillating motion, an actuator for directing the clamp claws in the thickness direction of the clamp portion is required compared to the prior art. This results in great practical benefits such as simplified structure, reduced weight and size of the device, and reduced device cost and maintenance man-hours.

[Brief explanation of the drawing]

Figure 1 shows an embodiment of this invention;
3 is a view showing an example of application of the apparatus shown in FIG. 1, FIG. 4 is a view showing another embodiment of this invention, and FIG. 5 is a perspective view showing a conventional example. 21, 22... Clamp claw, 23... Base plate, 24, 28... Mounting bracket, 25,
29...hinge pin, 26...arm, 27...
Swing lever, 30, 31... Elastic means, 32...
Bearing section, 33, 34... Servo motor, 35...
Cylinder, 36... Advance/retreat rod.

Claims (1)

[Claims for Utility Model Registration] A fixed side and a movable side are attached to each of the base plate 23 protruding from the bearing part 32 and the swing lever 27 connected to the base plate 23, and are located opposite to each other. A plurality of pairs of individual clamp claws 21 and 22, an actuator 35 that opens and closes the movable clamp claw 22 via the swing lever 27, and a change in the posture of the pair of clamp claws with respect to the workpiece. In a work clamping device including a plurality of other actuators, each of the pair of clamp claws 21 and 22 is attached to the hinge pin of the swing lever 27 to the mounting brackets 24 and 28 provided on the base plate 23 and the swing lever 27, respectively. The clamp claws 21 of the swing levers 27 are pivotally supported by hinge pins 25 and 29 extending in a direction perpendicular to the swing lever 27 so as to be swingable within the same plane in a direction perpendicular to the swing surface of the swing lever 27. , 22 to the neutral position by elastic means 30, 31, and the pair of clamp claws 21, 22 are pressed against their respective hinge pins 2.
5 and 29, respectively, or actuators 33 and 34 that rotate around two axes that are parallel to these axes.