JPH0243636Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a work clamping device, and particularly to a work clamping device that is placed on a machine table when machining a soft or brittle workpiece such as a hard urethane material. Regarding.

[Prior art]

Clamping devices used in machine tools are equipped with a cylinder device to make it easier and faster to attach and detach the workpiece when holding the workpiece fixedly.
-4658, JP-A-59-205010), or one in which the clamp claw can be moved inside the workpiece in response to the specific shape of the workpiece (JP-A-59-205010).
30630), which securely holds a cylindrical workpiece with a V-block and a swinging holding plate (Utility Model No. 59-
120534) have already been provided.

[Problems to be solved]

However, in conventional workpiece clamping devices, it is difficult to properly clamp and hold a soft or brittle workpiece to a degree that does not cause deformation or damage to the soft or brittle workpiece, while also satisfying contradictory conditions such as ensuring that the workpiece is held securely during machining. No device has yet been provided that achieves this under a sufficient clamping pressure.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a workpiece clamping device that is configured to hold a workpiece with a constant clamping pressure suitable for the material when machining a soft or brittle workpiece.

[Means of solution and action]

In view of the above-mentioned purpose, the present invention provides a work clamping device in which a fixed clamp jaw and a movable clamp jaw are arranged vertically opposite each other on a base placed on a table of a machine tool, and a workpiece is clamped at a predetermined pressure between the two clamp jaws. A clamp plate disposed opposite to the fixed clamp jaw, a fixed needle for clamping a workpiece provided on the clamp plate, and a movable rod pivotally attached to the clamp plate at one end and having a pressure receiving flange between the other end. a slider that carries the movable clamp jaw and is slidable in the vertical direction; and a slider that has both ends attached to the slider and that is looped under tension around the guide roller and the drive roller. A belt drive mechanism that clamps the slider together with the movable clamp jaw toward the fixed clamp jaw by rotationally displacing the frictionally engaged transmission belt by a drive motor M coupled to the drive roller; The movable rod of the clamp jaw has one end engaged with the pressure receiving flange and the other fixed end, and the workpiece is compressed via the movable rod until the clamping pressure of the workpiece by the fixed clamp jaw and the movable clamp jaw reaches the predetermined pressure. a deformable clamp pressure setting spring, a dock member attached to an index rod provided at the tip of the movable rod of the movable clamp jaw, and when the clamp pressure setting spring is compressed and deformed to the predetermined pressure via the movable rod; ,
clamp pressure detection means comprising a detection switch that detects the approach of the dog member of the index rod and generates a stop signal for the belt drive mechanism; The present invention provides a workpiece clamping device configured to make the relative position between the switch and the switch variable, thereby making it possible to change the predetermined pressure value. The belt drive mechanism automatically clamps the workpiece by selectively applying it.

Hereinafter, the present invention will be explained in detail based on examples.

〔Example〕

FIG. 1 is a longitudinal sectional view of the work clamping device according to the present invention, FIG. 2 is a front view taken in the direction of arrow A in FIG. 1,
FIG. 3 is a partial front view showing an enlarged view of the clamp pressure detection means of the device.

1 to 3, the workpiece clamping device according to the present invention has a base 10 installed on a base 12 (or a table) of a machine tool,
This base 10 is formed to have the same structure as a normal tombstone. In the case of this embodiment, both plates 16 are attached to the vertical ribs 14a formed on the front surface of the frame 14 of the base 10 by appropriate threaded bolts 18, and the front surface of the face plate 16 serves as a workpiece holding surface. used. That is, a fixed clamp jaw 20 for supporting the workpiece W is fixed to the lower center of the face plate 16 by screw bolts 22 and a receiving plate 23, and a clamp is attached to the upper edge of the fixed clamp jaw 20 supporting the workpiece as necessary. A needle 24 is provided. That is, when the work W is a soft and brittle work such as a urethane-based material, the clamp needle 24 is implanted to prevent slippage. Above the fixed clamp jaw 20, there is a slider 28 holding a movable clamp jaw 26, which will be described later.
A slider guide 30 that slides downward is provided. Now, the slider 28 has both ends of a wire 34 of a belt drive mechanism 32 locked on its back surface, and this wire 34 is connected to a lower guide roller 3 attached to the vertical rib 14a via a lower bracket 36.
8. Also the vertical rib 14 via the upper bracket 40
The upper guide roller 42 attached to a and the base 10
It is stretched under a certain tension so that it can run around a plurality of rollers such as a drive roller 46 held behind the frame 14 via a suitable bracket 44, and the drive roller 46 is connected to a drive motor. When rotated by M, the belt drive mechanism 32 applies running force to the wire 34 due to frictional conduction force between the drive roller 46 and the wire 34. As the wire 34 of the belt drive mechanism 32 runs, the slider 28 is moved downward toward the fixed clamp jaw 20 or vice versa.
It slides along the slide guide 30 so as to move away from zero. Here, the upper bracket 40
is formed so that it can be adjusted up and down with respect to the vertical rib 14a using an adjustment bolt 48, thereby making it possible to adjust the tension of the wire 34 via the guide roller 42. It's summery. Note that although a wire is used as the transmission belt in this embodiment, it goes without saying that a timing belt or the like may also be used. Further, the drive motor M of the belt drive mechanism 32 described above is appropriately rotated in both forward and reverse directions by an operator operating an external operation panel 50, whereby the slider 28 is moved in a clamped manner (downward). It is configured so that it can be moved up or unclamped (upwards).

The movable clamp jaw 26 carried by the slider 28 described above has a horizontally long clamp plate 52 at the lower end, and this clamp plate 52 is connected to the fixed clamp jaw 2.
The work W is clamped and held in cooperation with the upper edge of the work support of No. 0. And this clamp plate 5
Similar to the clamp needle 24 described above, a clamp needle 54 is provided at the lower edge of the clamp needle 2 as necessary to hold a soft and brittle work material without slipping. The clamp plate 52 is pivotally connected to a movable rod 58 by a pivot pin 56, and the movable rod 58 projects into a spring case 60 and supports the lower end of a spring 62 disposed within the spring case 60. flange 6
It has 4. The upper end of the spring 62 is engaged with a spring seat 66 of the spring case 60. Note that, as will be described later, this spring 62 is provided as a spring for setting the clamp pressure. Further, an index rod 68 is provided at the upper end of the movable rod 58, and this index rod 68 protrudes into the inside of a transparent case 70, and is connected to a proximity switch fixedly arranged inside the transparent case 70 using an appropriate mount 72. 74 (see FIG. 3)) to constitute a clamp pressure detection device.

The operation of the work clamp device of the present invention having the above-mentioned configuration will be explained below.

Now, when machining a soft or brittle workpiece W, first fix this workpiece W with the clamp jaw 2.
The movable clamp jaw 26 is moved downward toward the fixed clamp jaw 20 together with the slider 28 by operating the external operation panel 50 while supporting the workpiece on the upper edge of the work support. When the clamp plate 52 of the movable clamp jaw 26 comes into contact with the workpiece W, the clamp plate 5
2 is pivotally connected by the pivot pin 56, so
It acts to press the workpiece W from above by imitating the shape of the upper line. As a result, the movable rod 58 overcomes the spring force of the spring 62 and rises due to the reaction of this pressing force. At this time, the indicator rod 68 provided above the movable rod 58 rises, thereby actuating the proximity switch 74 to generate a set pressure detection signal. In other words, a set pressure detection signal that detects when the clamp pressing force applied to the workpiece W by the clamp plate 52 of the movable clamp jaw 26 has reached a predetermined pressure according to the amount of deflection of the spring 62 approaches in the form of an electric signal. It is generated from switch 74. Therefore, by using this set pressure detection signal as a stop signal for the drive motor M of the belt drive mechanism 32, the movable clamp jaw 26 can be stopped when a predetermined clamp pressure is reached. This drive motor M is a brake motor,
When stopped, the brakes are applied to prevent reverse rotation.

Note that the above-mentioned embodiment is based on the fixed clamp jaw 2.
0 and the movable clamp jaw 26 are arranged facing each other at the top and bottom to clamp the workpiece W at the top and bottom and machined with the tool T. It can also be configured to be clamped from the left and right lateral directions. Further, the spring strength of the spring 26 that sets the clamping pressure is selected in advance so as to exert a clamping pressure according to the softness of the workpiece W to be clamped, the degree of brittleness, and the working force during processing such as cutting force. Further, the set pressure detection means is configured such that the position of the dog 76 or the proximity switch 74 can be adjusted so that the clamp pressing force can be set as desired. Further, the proximity switch which cooperates with the indicator rod 68 to form the set pressure detection means may be replaced by a reed switch, a photoelectric detector, etc. to form the set pressure detection means. In addition, soft or brittle workpieces are not limited to polyurethane materials, but can also be made of gypsum material, wood, etc. as necessary.
Needless to say, it can also be applied to metal materials with high softness.

[Effect of idea]

As is clear from the above explanation, according to the present invention, a workpiece clamping device that clamps soft or brittle workpieces with the optimum clamping pressure for each workpiece material and securely clamps them during machining can be easily and easily created. This has the effect of being realized by a low-cost structure.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a workpiece clamping device according to an embodiment of the present invention, FIG. 2 is a front view taken in the direction of arrow A in FIG. 1, and FIG. The partially enlarged front view shown. 10...Base, 20...Fixed clamp jaw,
26...Movable clamp jaw, 28...Slider, 32...Belt drive mechanism, 34...Wire, 38, 42...Guide roller, 46...Drive roller, 52...Clamp plate, 24, 54...Clamp needle , 56... Pivot pin, 58... Movable rod, 6
2... Spring, 74... Proximity switch.

Claims (1)

[Scope of Claim for Utility Model Registration] In a work clamp device, a fixed clamp jaw and a movable clamp jaw are provided in a vertically opposed arrangement on a base placed on a table of a machine tool, and a workpiece is clamped at a predetermined pressure between the two clamp jaws. A clamp plate 52 provided opposite to the fixed clamp jaw 20, a fixed needle 54 for clamping the workpiece provided on the clamp plate 52, and a pressure receiving flange 64 which is pivotally connected to the clamp plate 52 at one end and is connected to the other end.
a slider 28 that carries the movable clamp jaw 26 and is provided to be slidable in the vertical direction and has a movable rod 58 having a movable rod 58; The slider 28 is moved around the movable clamp jaw by rotationally displacing the transmission belt 34 which is in a loop-like frictional engagement under tension around the drive roller 46 and the drive roller 46 by a drive motor M coupled to the drive roller 46. 26, a belt drive mechanism 32 that clamps the movable rod 58 of the movable clamp jaw 26 toward the fixed clamp jaw 20; and a clamp pressure setting spring 62 that can be compressed and deformed via the movable rod 58 until the clamping pressure of the workpiece by the movable clamp jaw 26 reaches the predetermined pressure.
When the dock member 76 attached to the index rod 68 provided at the tip of the movable rod 58 of the movable clamp jaw 26 and the clamp pressure setting spring 62 are compressed and deformed to the predetermined pressure via the movable rod 58, Detecting the approach of the dog member 76 of the indicator rod,
and a detection switch 74 for generating a stop signal for the belt drive mechanism 32, and a dock member 76 of the clamp pressure detection means.
and a proximity switch 74, the relative positions of which are made variable so that the predetermined pressure value can be changed.