JPS628907Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of a control valve operating device for an air stand hammer.

By the way, the operation direction switching control valve that controls the air cylinder for raising and lowering the ram of the air stand hammer supplies air to the side that lowers the ram when the internal valve body is raised from the neutral position to the cylinder. When the valve body is lowered from the neutral position, air is supplied to the side where the ram is raised.

Such control valves are typically operated by a device that includes a foot-operated pedal and an arcuate cam that slides against the side slope of the ram and responds to the raising and lowering movements of the ram. In other words, this control valve is operated to lower the ram by depressing the pedal, and then is operated to raise the ram by the movement of the bow-shaped cam and releasing the pedal, and then by depressing the pedal again. Unless lowered, the ram is stopped at a predetermined upper limit.

However, in such a control valve operating device, since it is necessary to keep the above-mentioned arcuate cam in sliding contact with the side slope surface of the ram at all times, the valve weight of the control valve with respect to the arcuate cam is controlled by the cam. The load is applied in the direction in which the control valve is pressed, and this state is maintained even when the control valve is operated. Therefore, when lowering the ram, the pedal must be depressed with a strong force that can counteract the total weight of the valve body and the bow-shaped cam, making it difficult for the operator to operate the control valve, especially when depressing the pedal. This puts a heavy burden on the pedal, and the foot that depresses the pedal gets tired very easily.

The present invention addresses the above-mentioned conventional problems with the control valve operating device for air stand hammers, and provides a means for offsetting the weight of the valve body of the control valve in order to enable easy operation of the control valve. In place of the valve weight, a means for pressing the arcuate cam against the side inclined surface of the ram is also used, so that the valve weight is not applied to the pedal side of the device. Hereinafter, an embodiment shown in the drawings will be described in detail.

In the figure, reference numeral 1 denotes an anvil serving as the base of the entire air stand hammer, and a pair of left and right frames 2, 2 are erected on top of the anvil, supporting a cylinder block 3. This block 3 has a vertical ram elevating air cylinder 4, which houses a piston 5, and 6 is a piston rod integrated with the piston, which hangs down from the lower end of the cylinder 4 between the frames 2. has been done. 7 is a ram integrally attached to the lower end of the piston rod 6,
It is movable up and down along ram guides 8, 8 provided on the inner surfaces of both the left and right frames 2, 2, and a set of forged tops are provided on the lower surface of the ram 7 and the upper surface of the saw block 9 on the anvil 1. Mold 10a and lower mold 1
0b are attached respectively. Reference numeral 11 denotes a control valve for switching the operating direction of the air cylinder 4, and is provided in the cylinder block 3. As is well known, the control valve 11 has a vertical valve housing 12 and a valve body 13 accommodated in the vertical valve housing 12 so as to be movable up and down, and 14 is a valve shaft integrated with the valve body 13. The valve housing 12 of the control valve 11 is connected to the air supply pipe 1
The air supply port 12a is connected to a suitable compressed air source through the air cylinder 5, the exhaust port 12b is opened to the atmosphere through the exhaust pipe line 16, and the air cylinder is connected through the upward air passage 17. The valve body 13 has a rising port 12c that communicates with the lower end of the cylinder 4, and a descending port 12d that communicates with the upper end of the cylinder 4 via the descending air passage 18. , each of the above ports 12a
~12d are all closed, and when lowered, between ports 12a and 12c and between ports 12b,
12d are communicated with each other, and when raised, communication is established between ports 12a and 12d and between ports 12b and 12.
The inside is hollow and has an hourglass shape so that each space can be communicated with each other. 19 is a known operating device for operating the above-mentioned control valve 11, and the pedal 2
A lower operating rod 21 that is lowered when the user depresses the pedal, and a rocker arm 2 that is pivoted in the middle with a pin 22 and that the upper end of the rod 21 is connected to one end.
3, and an arcuate cam 2 which is pivotally supported at the other end of the arm by a pin 24 and slidably contacts the side inclined surface 25 of the ram 7.
6, an upper operating rod 28 whose lower end is connected to the tip of a cam arm 27 integrated with the cam, and a link which is pivotally supported by a pin 29 and whose tips are connected to the upper ends of the rod 28 and the valve shaft 14. It consists of 30.

The present invention is implemented as follows for the above-mentioned operating device for such an air stand hammer.

First, a balancing pneumatic unit 31 is provided for the control valve 11. This unit 31 consists of a cylinder 32 and a piston 33, and includes a control valve 1
The valve body 13 shall be mounted so that a weak pneumatic pressure necessary to balance the weight of the valve body 13 can be applied upward to the valve body 13. Therefore, in the illustrated example, the cylinder 32 is installed on the valve housing 12 of the control valve 11, and the portion of the valve shaft 14 that protrudes above the valve housing is attached to the cylinder 32.
2, and the above-mentioned piston 33 is inserted into the shaft so that the valve shaft 14 serves as a piston rod.
It is said that the structure combines unit 31.
The entire valve shaft 14 may be installed parallel to the valve shaft 14, and the shaft and the piston rod may be integrally connected by a suitable connecting member. A pressing pneumatic unit 34 is also provided for the arcuate cam 26.
This unit 34 consists of a cylinder 35 and a plunger 36, and is designed to apply to the arcuate cam 26 the minimum weak pneumatic pressure necessary to keep it in sliding contact with the side inclined surface 25 of the ram 7. shall be installed. Therefore, in the illustrated example, the arcuate cam 26
A cylinder 35 is installed on the side opposite to the ram 7, and the tip of the plunger 36 is brought into contact with the back surface of the cam. These pneumatic units 31 and 34 are supplied with relatively low pressure compressed air necessary to apply the required pneumatic pressure to the above-mentioned valve body 13 or the arcuate cam 26. 37 through a pressure reducing valve 38.

In the above configuration, when the pedal 20 is depressed, the rod 21 is pulled down, and the rocker arm 23 is rotated clockwise about the pin 22. Then, the entire arcuate cam 26 is raised by the pin 24, and the cam arm 27 integrated with the cam is raised.
Since the upper operating rod 28 is pushed up at the tip of the control valve 11, the valve body 13 of the control valve 11 is pulled up by the valve shaft 14 via the link 30, thereby connecting the port 12c to the port 12b and the port 12a to the port 12d, respectively. However, the weight of the valve body 13 is balanced out by the pneumatic pressure applied upward from the pneumatic unit 31, and no load is applied to the pedal 20. Therefore, at this time, the pedal 20 is connected to the arcuate cam 26.
It is possible to lightly step down with the slight force required to counter the weight of the machine.

By the way, when the control valve 11 is operated as described above, the compressed air sent to the lower part of the air cylinder 4 is transferred from the air passage 17 to the port 1 of the control valve 11.
2c and 12b and is discharged into the atmosphere from the exhaust pipe passage 16, the ram 7, which had been kept in the raised position by the air pressure, begins to descend by its own weight. Also, at this time, the compressed air supplied from the compressed air source 37 to the air supply line 15 is lowered by its own weight to be sent from the air passage 18 to the upper part of the air cylinder 4 via the ports 12a and 12d of the control valve 11. The ram 7 that has started is energized by its air pressure. Therefore, the ram 7 rapidly descends, and the upper forging die 10a strongly strikes the workpiece material on the lower forging die 10b.

On the other hand, the valve body 13 of the control valve 11 that has been pulled up as described above is moved downward by the downward movement of the bow-shaped cam 26 based on its own weight when the depressing load of the pedal 20 is removed.
The pedal 20 is then lowered via the valve shaft 14, and the corresponding rotation of the rocker arm 23 in the counterclockwise direction causes the pedal 20 to return to the position before being depressed. This arcuate cam 26 is pressed against the side inclined surface 25 of the ram 7 by pneumatic pressure applied from the pneumatic unit 34, and remains in sliding contact with the inclined surface. Therefore, when the ram 7 is lowered as described above, the arcuate cam 26 sliding on the side inclined surface 25 of the ram 7 moves the pin 2 according to the angle of inclination of the inclined surface.
4 as a fulcrum, and in order to pull down the rod 28 via the cam arm 27, the valve body 13 is further lowered beyond its original neutral position, and the valve body 13 is moved from the port 12a to the port 12c. Ports 12d are connected to ports 12b, respectively. Then, the compressed air that had been fed into the upper part of the air cylinder 4 is released into the atmosphere from the ports 12d and 12b through the exhaust pipe 16, and is newly released into the air from the ports 12a and 12.
Since compressed air is sent to the lower part of the air cylinder 4 from c, the lowered ram 7 is raised, and when this ram returns to its original position, the pedal 20
unless the arcuate cam 2 is pressed down again.
Since the valve body 13 is pulled up to the original neutral position by the back movement of the valve 6 following the ram, the ram 7 remains stationary at the raised position.

As described above, the present invention relates to a device in which the control valve for switching the operating direction of the air cylinder for raising and lowering the ram in an air stamp hammer is operated by a pedal that is operated by being stepped on by the foot and an arcuate cam that responds to the raising and lowering movement of the ram. The valve weight of the valve is balanced with the pneumatic pressure applied from the pneumatic unit to offset it so that no load is applied to the pedal side, and the bow-shaped cam is also brought into sliding contact with the side inclined surface of the ram using pneumatic pressure. Therefore, according to the present invention, the pedal can be pressed down easily without impairing the function of the bow-shaped cam, and the burden on the worker, especially the strain on the foot of the person who depresses the pedal, can be reduced. It can be relaxed to a large extent.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view showing an embodiment of the present invention, and FIG. 2 is a partially cutaway enlarged view showing the main parts thereof. 4...Air cylinder for raising and lowering the ram, 7...Ram,
11...Operation direction switching control valve, 13...Valve body,
20...Pedal, 25...Side inclined surface, 26...
Bow-shaped cam, 31, 34...pneumatic unit.

Claims (1)

[Scope of utility model registration request] In a device in which a valve body in a control valve for changing the operating direction of an air cylinder for raising and lowering a ram is raised and lowered using a pedal that is depressed by the foot and an arcuate cam that responds to the raising and lowering of the ram, there is a valve located near the control valve. A pneumatic unit is installed to apply a weak upward pneumatic pressure to the valve disc that balances the weight of the valve disc, and a pneumatic unit is installed behind the arcuate cam to apply a weak pneumatic pressure in the direction of lightly pressing the cam against the side slope of the ram. A control valve operating device for an air stamp hammer, characterized by being equipped with a pneumatic unit that applies air pressure to a cam.