JPH0222189Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a clamp device for fixing a press mold etc. that is attached to the bed of a press machine.

[Conventional technology]

2. Description of the Related Art Clamp devices for fixing a die or a lower frame of a die set onto the bed of a press machine are well known.

In this known clamp device, there are two types of drive means for operating the clamp claws: a manually operated cam type, and an automatic type using a hydraulic cylinder and a spring.

[Problem that the invention attempts to solve]

Among the conventional clamp devices mentioned above, the cam type clamp device engages the engaging portion of the handle with the engaging portion of the end of the camshaft, and the cam is rotated by the handle. Since the system relies on human touch, there is a problem that the clamp may be under-tightened or over-tightened, and it is not obvious if the clamp loosens during operation. Products that use hydraulic cylinders and springs can eliminate the above problems by controlling the oil pressure and spring pressure, but
In this case, it is difficult to accurately detect whether the tip of the claw is in close contact with the pressurized member, and it is not known whether the clamp claw is loosened during operation or the like.

[Means for solving problems]

In order to solve the above problems, this invention creates a slight gap between the bottom surface of the main body and the board toward the rear from the rear of the fixing means that fixed the clamp device main body to the board, and the bottom surface of the main body near the rear end. When the drive means pushes up the rear end of the clamp claw and presses the pressurized member onto the substrate with the tip of the clamp claw, the downward reaction force applied to the drive means attachment part of the main body causes the bottom surface of the main body to It is equipped with a proximity sensor that detects the approach of the board and the board.

[Effect]

Since this invention has the above-mentioned configuration, the object to be pressed, such as the side edge of a mold placed on the bed of a press, is placed under the tip of the clamp claw.

The proximity sensor is inactive while the gap between the bottom surface near the rear end of the main body and the board remains unchanged, but the rear end of the clamp claw is pushed up by the action of a cam or hydraulic cylinder attached to the main body, and the tip of the clamp claw is pushed up. When the pressurizing surface presses against the upper surface of the pressurized member, the reaction force causes the bolts or the like fixing the main body to the substrate to bend slightly within their elastic limits, causing the rear bottom surface of the main body to approach the substrate.

In this way, it can be seen that when the rear bottom surface of the main body approaches the substrate, the proximity sensor is activated and the tip of the clamp claw presses the pressurized member onto the substrate.

〔Example〕

The drawing shows a cam type, and the Y in Fig. 2
1 is a board such as the bed of a press machine, and this board 1
The main body 2 is fixed on the top by means such as bolting.

Reference numeral 3 denotes a horizontal shaft that passes through the front side of the main body 2 and is fixed, and its both ends protrude from both sides of the main body 2. This protruding portion passes through a hole in the middle of the pair of left and right clamp claws 4, and each claw 4 can swing about the horizontal axis 3 as a fulcrum.

Furthermore, washers for preventing the clamp claws 4 from coming off are fixed to both ends of the horizontal shaft 3 with bolts.

Reference numeral 5 denotes a camshaft mounting hole provided near the rear of the main body 2, and a camshaft 6 is fitted into this hole 5 so as to be rotatable and movable up and down.

The cam shaft 6 has a cam portion 7 at its center, a circular clamp claw pushing portion 8 on both sides thereof, and an engaging portion 9 having a hexagonal shape or the like at its outer end.

The center part of the mounting hole 5 of the main body 2 is a cam hole 10 having a slope 14 as shown in FIG. 3, and the shape of both ends is as shown in FIG.
It has a shape that fits the lower half of the push-up part 8 so that the push-up parts 8 at both ends of the push-up part 8 fit together and become stable, and above it is a tapered guide part 11 whose outer end is widened. Further, the cam portion 7 of the camshaft 6 enters the cam hole 10, and the inner end portion of the push-up portion 8 fits into the guide portion 11 so as to be rotatable, raised and lowered, and swingable.

Reference numeral 12 denotes a presser spring made of a plate spring, which is fixed onto the main body 2 by screwing or other means, and the forward-facing ends 13 of this spring 12 push down the rear end of each clamp claw 4 to release the slope 15 at the bottom thereof. is pressed against the push-up portion 8 of the camshaft 6. Note that the cam portion 7 is an equiangular helical cam.

18 in FIGS. 1 and 2 are two bolts on the left and right as fixing means for fixing the main body 2 to the board 1,
As shown in FIG. 2, the bottom surface of the main body 2 forms a slope 19 that gradually becomes higher toward the rear from a distance a of 0.3 to 0.5 d of the diameter d of the bolt 18 from the rear end of the bolt 18.

In FIG. 2, the slope 19 is exaggerated, and in reality, the gap b between the rear end of the slope 19 and the top surface of the substrate 1 is about 0.02 to 0.03 mm. However, instead of slope 19, the range of slope 19 is raised one step, and slope 1
The gap b may be provided over the entire area of 9.

Reference numeral 20 denotes a vertical hole provided near the rear end of the main body 2. A proximity sensor 21 is fitted into the hole 20 and fixed with a set screw 22.

The proximity sensor 21 uses a known proximity switch. Therefore, the proximity sensor 21 can be of various types, and FIG. 4 shows one example.

In FIG. 4, a combination of a detection coil 23 and a capacitor 24 is used as the proximity sensor 21, which is connected to a transmission circuit 26 by a cord 25, and a detection circuit 27 is connected to the output terminal of the transmission circuit 26.
The threshold switch circuit 28 and the output circuit 29 are connected in sequence.

Reference numeral 30 denotes a power supply, which is supplied to the transmitting circuit 26 and the like via a constant voltage circuit 31.

In the above embodiment, when the camshaft 6 is in the inactive position, the lower part of the cam portion 7 is located at the cam hole 10.
Since the camshaft 6 is in contact with the slope 14 of , the camshaft 6 is located at the lower side, and therefore the tip portion 33 of each clamp claw 4 is raised.

In this state, the side edge 34 of the press mold as a pressurized member on the substrate 1 is held at the tip 33 of each clamp claw 4.
When the camshaft 6 is rotated by engaging a handle or the like with the engaging part 9, the outer periphery of the cam part 7 slides while contacting the slope 14 of the camshaft mounting hole 5. Rise while rotating.

As the camshaft 6 rotates and rises as described above, each pushing part 8 on both sides pushes up the slope 15 of each clamp claw 4, so that each clamp claw 4 has its tip 33 as shown in FIG. is pressed onto the side edge 34 and clamped. At this time, if the thickness of the side edge 34 in contact with each clamp claw 4 is different, the camshaft 6 rotates while tilting according to the difference in thickness, which is a so-called misosuri movement. The rear end of each clamp claw 4 is pushed up in a state where the reaction forces are balanced. To release the clamp, the camshaft 6 may be rotated in the opposite direction.

In the above operation, if a constant voltage from the constant voltage circuit 31 is applied to the detection coil 23 etc., the Q of the detection coil 23 is kept constant.

Therefore, when the pressurizing surface 36 of the clamp claw 4 is away from the upper surface of the side edge 34, the gap b is kept at the maximum, so the Q of the coil 23 is also kept constant and the proximity sensor 21 does not work.

However, when the pressure surface 36 of the tip 33 of the clamp claw 4 presses against the upper surface of the side edge 34 due to the action of the camshaft 6, and the reaction force is applied to the camshaft 6 as a downward force, the force is applied to the camshaft 6 via the camshaft 6. The rear part of the main body 2 is strongly pushed downward.

Therefore, the main body 2 is positioned at the second position from the rear end of the bolt 18.
As the bolt 18 attempts to rotate to the right toward FIG. 2 using the part that is separated from the rear by the distance a shown in the figure as a fulcrum, a bending load is applied to the bolt 18, and the bolt 18 bends slightly backward within its elastic limit, causing the bottom of the main body 2 to slope 19
approaches the substrate 1, and the gap b becomes smaller.

In this way, the detection coil 2 is attached to the substrate 1 which is a metal object.
3 approaches, its Q changes and therefore the transmission output of the transmission circuit 26 changes. This change is detected and rectified by the detection circuit 27, discriminated by the threshold switch circuit 28, and outputted as a signal 35, which indicates that the clamp claw 4 has pressed down the side edge 34.

When tightening manually, the proximity sensor 21
When the output signal 35 from the operation is received, it is sufficient to stop the tightening, and in the case of automatic operation using hydraulic pressure or the like, the control amplifier may be operated according to the output signal as described above to stop the tightening using the hydraulic pressure or the like.

Note that the above embodiment is just an example, and there are cases in which the left and right clamp claws are moved up and down by cams provided at both ends of the camshaft, and in which one clamp claw is provided in the center of the main body and moved up and down by the cam in the center of the camshaft. There are things that make you do it.

Also, in the case of a hydraulic type, there are cases in which a hydraulic cylinder tightens the clamp claw and a spring returns it to its original position, and vice versa.

〔effect〕

As mentioned above, this idea creates a slight gap between the bottom of the main body and the board toward the rear from the rear of the fixing means that fixes the main body to the board. Since the device is equipped with a proximity sensor that detects When the rear part of the bottom of the main body approaches the board due to the downward reaction force applied to the part, the proximity sensor activates and emits a signal, so you can immediately know that the clamp claw has clamped the pressurized member, and it is possible to prevent any damage during clamping. If the tightening means of the clamp claw becomes loose due to this and the clamping force weakens, the proximity sensor moves away from the board due to the recovery of the body fixing means such as bolts, and the output signal disappears or changes, so the loosening of the clamp claw can be quickly detected. There are effects such as being able to.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing one embodiment of the clamping device of this invention, FIG. 2 is a front view of the same, FIG. 3 is a rear longitudinal sectional front view of the main body, and FIG. 4 is an electric circuit diagram. 1... Board, 2... Main body, 3... Horizontal axis, 4...
Clamp claw, 18... Bolt, 19... Slope, 2
1... Proximity sensor, 33... Tip, 34... Side edge, b... Gap.

Claims (1)

[Scope of utility model registration request] A clamp claw is attached to the front part of the main body fixed on the board so that it can swing freely by the horizontal axis, and the rear part of the main body is
In a clamping device that is provided with a driving means for moving the rear end of the clamp claw up and down, a slight gap is provided between the bottom surface of the main body and the board facing rearward from the rear of the fixing means that fixed the main body to the board, and On the bottom of the main body, there is a downward reaction force that is applied to the drive means mounting part of the main body when the drive means pushes up the rear end of the clamp claw and presses the pressurized member onto the board with the tip of the clamp claw. A clamping device equipped with a proximity sensor that detects the proximity of the bottom of the main body and the board.