JPH0732269U - Double valve for press - Google Patents

Abstract

(57) [Summary] [Purpose] Compact, inexpensive, highly reliable with no false detection, and capable of supporting future trends in automated equipment with fault diagnosability. It is an object of the present invention to provide a double valve for a press that does not require troublesome adjustment such as actual matching of orifices, does not use an orifice having a small diameter in an air circuit, and is not affected by the quality of air used. [Composition] In a double valve for press equipped with two flow path switching valves in which an intake port and an operating port are connected in parallel to a fluid circuit, a proximal end is pivotally attached, a magnet is fixed at the distal end, and a flow path is switched by a spring. A lever urged to the main valve side of the valve is arranged so as to face the main valve, and a magnetically sensitive switch is provided at a position which is sensitive to the magnet at the tip of the lever by the rotation of the lever as the main valve moves. In addition, a double valve for press has an electric variable timing circuit connected between the flow path switching valve solenoid and the start switch.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a double valve for a press, and more particularly to a monitor device for a press and a timing adjusting device.

[0002]

[Prior art]

 In the control fluid circuit used in the press machine, double control valves are provided for safety, and if one control valve fails, the double valve will not operate even if there is no failure in the other. Is required by law. When such a double valve is used, it is necessary to detect valve malfunction or valve failure. As one conventionally used, there is one shown in FIG.

In FIG. 6, a three-port valve is used to switch between a compressed air supply port P, an operation port A for the press machine, and a discharge port R for discharging the compressed air to the outside. Two valves 101 and 101 'are arranged in parallel as a double valve. The monitor 102 for detecting malfunctions or failures of the valves 101 and 101 'has a piston 102a that can freely slide and a micro switch 102b that detects the movement of the piston 102a, as shown by the broken line in the figure. A conduit 103, which opens toward one end of the piston 102a, is connected to a connected portion of the working port A via a throttle 104.

Normally, the same fluid pressure is applied to both ends of the piston 102a, the piston 102a is held in a neutral position, and the flow paths of the fluid are switched by switching the valves 101 and 101 '. When one valve 101 is defective, a difference in fluid pressure between both ends of the piston 102a causes the piston 102 to move and actuate the micro switch 102b. In reality, there are variations in the working accuracy of the valves 101 and 101 'and the monitor 102, and there are variations in the accuracy of the springs used in the valves 101 and 101' and the monitor 102. Further, there is an electrical phase difference acting on the coils of the solenoids of both valves 101 and 101 ', and it is difficult to accurately synchronize both valves 101 and 101'. That is, even if an electric signal is given at the same time, there may be a case where the valve is switched.

In order to prevent the monitor 102 from giving an abnormal instruction due to the operation deviation of the two valves 101 and 101 ′ due to such working accuracy and spring accuracy, the piston 102 a of the monitor 102 is It is necessary to form a communication hole 102c that communicates between both ends so that the pressure difference between both ends of the piston 102a within a certain range is absorbed by the communication hole 102c and does not reach until the piston 102a moves. Has been done.

The smaller the diameter of the communication hole 102c, the more sensitive the operation becomes, and the piston 102a moves even with a slight pressure difference, so that a slight operation shift of both valves 101 and 101 'is detected. On the contrary, if the diameter is increased, the piston 102a does not operate until the pressure difference becomes considerable, so that it does not respond to a certain amount of operation deviation. If the diameter is too large, you will not feel any malfunction, so there is a limit to increasing the diameter. In the method in which the diameter of the through hole 102c of the piston 102a is increased or the number of holes is increased to make it insensitive to the operational deviation of the two valves 101 and 101 ', one valve is detected when malfunction or failure of the valve is detected. This means that the press has started operating and will stop halfway.

In the event of valve malfunction or failure, the press is preferably stopped and inspected by switching the valve without starting any operation. For this purpose, it is desirable that the communication hole 102c provided in the monitor piston has a structure in which the pressure difference is as sensitive as possible. Satisfying both of the above-described detection of malfunction and the operation deviation in the normal state is a contradictory request in the conventional monitor 102, and a satisfactory result cannot be obtained.

As a monitor device for detecting malfunction of the double valve for press or failure of the valve as described above, Japanese Patent Publication No. Sho. is there. In addition to this, there is a piston-switch system as a monitor device, which has a proximity switch that is brought into conduction by the movement of the main valve of the flow path switching valve, which has already been proposed, for example, as Japanese Utility Model Publication No. 3-125965. Has been done.

There are two types of clutches and brakes used in mechanical presses, a clutch / brake combination type and a clutch / brake separate type. The clutch / brake combination type does not operate because the clutch and brake are integrated and the clutch and brake do not overlap. In this case, only one double valve is required.

The flywheel of the press machine is constantly driven by a motor. When the press machine is ON and OFF, the clutch / brake separate type has a separate clutch and brake. It is necessary to act in a timely manner. That is, in the case of ON operation, the brake must first be disengaged and then the clutch must be engaged, and in the case of OFF operation, the clutch must be disengaged first and then the brake must be applied. Therefore, two double valves are required, this double valve must be equipped with a timing adjusting device, and it is necessary to install a timing adjusting device.

A conventional flow path switching valve for a clutch of a press machine is as shown in FIG. 7, and comprises a suction port P for compressed air, an operation port A for the press device, and a discharge port R for discharging the compressed air to the outside. A three port valve is used to switch between them. The main valve 301 and the main valve 301 'are connected in parallel to the fluid circuit, and the portion surrounded by the broken line is the timing adjusting device 302. The timing adjusting device 302 includes the main valves 301 and 301', respectively. The pilot valves 303 and 303 'to be operated are connected, and the pilot valves 303 and 303' are further connected to the orifices 304 and 304 'for delaying the operation of the main valves 301 and 301'.

On the other hand, the flow path switching valve of the brake of the conventional press machine is as shown in FIG. 8, which has a suction air intake port P for compressed air, an operation port A for the press machine, and a discharge port R for discharging the air to the outside. A three-port valve that switches between is used. The main valve 401 and the main valve 401 'are connected in parallel to the fluid circuit, and the portion surrounded by the broken line is the timing adjusting device 402, and the timing adjusting device 402 includes the main valves 401 and 401', respectively. The pilot valves 403 and 403 ′ for operating are connected, and the pilot valves 403 and 403 ′ are further connected to the orifices 404 and 404 ′ for delaying the operation of the main valves 401 and 401 ′.

When the pilot valves 303, 303 ', 403, 403' are turned on, in FIG. 8 which is a flow path switching valve of the brake, compressed air passes from the intake port P through the pilot valves 403, 403 'and the throttle 404. -Activate valve 401-401 'immediately without passing through 404'. On the other hand, the flow path switching valve shown in FIG. 7, which is the flow path switching valve of the clutch, extends from the suction port P through the orifices 304, 304 ', the pilot valves 303, 303' to the main valves 301, 301 '. The main valves 301 and 301 'are activated after a delay. That is, in the case of ON operation, the brake is first released and then the clutch is engaged.

Further, when OFF, the orifices 304, 304 ′ of the flow path switching valve of the clutch do not operate, and when compressed air reaches the discharge port R from the main valves 401, 401 ′ having only the flow path switching valve of the brake, Since it passes through the orifices 404 and 404 ', the operation of the brake is delayed. That is, when it is OFF, the clutch is first disengaged and then the brake is applied.

[0015]

[Problems to be solved by the device]

 A conventional differential pressure detection piston system or a piston-switch system monitoring device is not always compact when installed in a press machine, and is particularly compact when installed in many automation devices. Development of a double valve monitor system for presses is awaited. There is also a need for a compact, inexpensive dual valve monitoring device for presses. Furthermore, it is necessary to eliminate the pressure inlet for detection, eliminate pseudo detection factors, and directly sense the movement of the main valve to improve reliability.

Furthermore, in view of the trend of automation equipment in the future, the monitor device must be capable of including a failure diagnosis device. On the other hand, as a dual valve timing control device for presses, an orifice is inserted in the air passages of the pilot valve and main valve to adjust the timing. For the timing adjustment using this orifice, the actual adjustment was to install the double valve on the press machine and then select the orifice diameter according to the actual product while operating the press machine.

Further, since the orifice usually has a hole diameter of about 1 mm, the orifice may be clogged depending on the condition of contamination in the air used, and the timing may be misaligned.

[0018]

[Means for Solving the Problems]

 Therefore, in view of the above circumstances, the present invention is compact, inexpensive, highly reliable with no false detection, has fault diagnosability, and is compatible with future trends in automated equipment. Two flow path switching valves with intake port and operation port connected in parallel to the fluid circuit to adjust the timing of ON and OFF with an electric variable timing circuit instead of the conventional pneumatic timing adjustment device. In a double valve for press equipped with, a base end is pivotally attached, a magnet is fixed to the front end, and a lever biased by a spring to the main valve side of the flow path switching valve is arranged facing the main valve, respectively. A magnetically sensitive switch is installed at the location where the magnet at the tip of the lever is activated by the rotation of the main valve of the lever, and an electric variable timing circuit is connected between the flow path switching valve solenoid and the start switch. It was to press for the double valve.

[0019]

[Action]

 The rotation of the lever as the main valve moves causes the magnetism-sensitive switch to respond to the magnetism of the magnet at the tip of the lever. Further, since the levers are provided respectively corresponding to the main valves of the flow path switching valve, when there is a failure in one of them, the lever correspondingly rotates according to each, and the failure can be detected.

Further, according to the present invention, since the electric variable timing circuit is connected between the flow path switching valve solenoid and the start switch, the timing adjustment time is continuously adjusted without being influenced by the orifice diameter by machining. This makes it easier to adjust the press machine. In addition, since there is no orifice in the air passage and it is not affected by the air quality, the press machine operates stably.

[0021]

【Example】

The present invention will be described in detail below based on a specific embodiment shown in the drawings. FIG. 1 is a vertical cross-sectional view of a specific embodiment of the present invention, which is provided with a suction port P for compressed air, an operation port A that operates with respect to a press device, and a discharge port R that discharges to the outside. It is a three-port valve in which valves 1.1 'are arranged in parallel, and main valves 2.2' of valves 1.1 'are coil springs 3' upwardly with a detection pin interposed. Energized to close the valve holes 4 and 4 ', and in the non-actuated state when the solenoids SOL ₁ and SOL ₁ ' are OFF, the suction port P is closed and the working port A communicates with the discharge port R.

During normal operation, the solenoids SOL ₁ and SOL ₁ ^′ are ON, the main valve 2 and 2 ′ opens the valve holes 4 and 4 ′ against the biasing force of the coil springs 3 and 3 ′, and the suction port P And the operation port A communicate with each other, the discharge port R is closed, and the press work is performed. Here, the detection pins 5.5 'are hung vertically below the main valve 1.1', and the monitor device 6, the terminal board 7 and the control circuit 8 are positioned below the detection pins 5.5 '. It is housed in the lower housing 9 made of die casting.

The control circuit 8 and the solenoids SOL ₁ and SOL ₁ ′ are electrically connected by a cable 10. Inside the cable 10, switches SW ₁ and SW ₁ ′ for opening and closing the solenoid are provided, and the control circuit 9 is provided. Is connected to the start switch SW. As shown in FIGS. 1, 2, and 3, the monitor device 6 is housed in a sheet metal casing 11, and the levers 12 and 12 'are arranged at positions where the lower ends of the detection pins 5 and 5'abut. The base end is pivotally attached to the inner side wall of the sheet metal housing 11 to the brackets 14 and 14 'screwed with bolts 13 and 13' with pins 15 and 15 ', and the magnets 16 and 16 are attached to the tips of the levers 12 and 12'. Tighten 'with screws 17 ・ 17'. In order to bias the levers 12 and 12 'upwards, coil springs 18 and 18' are contracted between the central lower surface of the levers 12 and 12 'and the bottom plate of the sheet metal housing 11. Further, the stopper 19 is screwed onto the upper plate of the sheet metal casing 11 at a position facing the tips of the levers 12 and 12 '.

The levers 12 and 12 ′ rotate around the pins 15 and 15 ′ due to the contact of the detection pins 5 and 5 ′, and the magnetic sensitive switches 20 and 20 are located at the positions sensitive to the magnetism of the magnets 16 and 16 ′. 'Is fixed. The magnetic sensitive switches 20 and 20 'electrically connect the terminal board 7 and the control circuit 8 by wirings 21 and 21' and 22 and 22 '.

Next, the operation of the double valve monitoring device for a press of the present invention will be described. When the solenoids SOL ₁ and SOL ₁ 'are off when the solenoids SOL ₁ and SOL ₁ ′ are OFF, the suction port P is closed and the working port A communicates with the discharge port R. In the state shown in Fig. 1, the main valves 2 and 2'are located above, so the magnets 16 and 16 'are outside the pitch operating range, and the magnetically sensitive switches 20 and 20' are in the OFF state. Yes, the coil opening / closing switches SW ₁ and SW ₁ 'are closed.

During normal operation, the solenoids SOL ₁ and SOL ₁ ′ are ON, and the main valves 2 and 2 ′ open the valve holes 4 and 4 ′ against the biasing force of the coil springs 3 and 3 ′, and the suction port P and the operating port A communicate with each other, the discharge port R is closed, and press work is performed. Erroneous operation, when the ON state by the activation switch SW in the state shown in FIG. 4, when the solenoid SOL ₁ 'side is not activated, only the main valve 2 solenoid SOL ₁ is moved downward direction, magnetically sensitive switch 20 is turned ON, the magnetic sensitive switch 20 'is so OFF, the control circuit 8 switches SW ₁ and SW ₁ for detecting and solenoid opening and closing malfunction' is turned OFF, the main valve 2 'is inoperative Return to the state.

Next, the timing adjusting device for the double valve for the press will be described. As shown in FIG. 5, it is a three-port valve equipped with a suction port P for compressed air, an operation port A that operates with respect to the press device, and a discharge port R that discharges to the outside. A valve 31 'is arranged in parallel with the fluid circuit. When the solenoids SOL ₃₁ and SOL ₃₁ 'are ON, compressed air flows in from the suction port P and flows out from the operation port A to perform pressing work.

When the solenoids SOL ₃₁ and SOL ₃₁ ′ are OFF, compressed air flows out from the main valve 31 and 31 ′ via the discharge port R. In the clutch or brake flow path switching valve of this press machine, an electric variable timing circuit 33 is electrically connected between the main valves 31, 31 'and the manual switch 32.

[0029] As the electric variable timing circuit 33, it is configured by a timer or IC, about 10～100Msec (preferably 60 msec) to actuate the solenoid SO L ₃₁ · SOL ₃₁ 'delayed electric signal . When this flow path switching valve is installed on the brake side, the signal from the start switch 32 during ON operation is transmitted to the solenoid SOL _{3 1} · SOL ₃₁ 'with the adjustment time 0 (instantaneous) in the electric variable timing circuit 33. It

In the OFF operation, even if the signal of the start switch 32 is cut off, the signal of the solenoids SOL ₃₁ and SOL ₃₁ ′ is cut off after a fixed time adjusted by the electric variable timing circuit 33. When this flow path switching valve is mounted on the clutch side, the signal from the start switch 32 is transmitted to the solenoids SOL ₃₁ and SOL ₃₁ ′ after a certain time period adjusted by the electric variable timing circuit 33 during ON operation.

When the signal of the start switch 32 is turned off during the OFF operation, the signals of the solenoids SOL ₃₁ and SOL ₃₁ ′ are turned off at the adjustment time 0 (instantaneous) in the electric variable timing circuit 33. As described above, when the electric variable timing circuit 33 is used, the adjustment of the press machine becomes easy because the conventional timing adjustment time depends on the orifice diameter by machining and cannot be adjusted continuously. Further, when the electric variable timing circuit 33 is used, since the orifice does not exist in the air passage and the air quality is not affected, the press machine operates stably.

[0032]

[Effect of device]

 As described above, the present invention is a double valve for a press having two flow path switching valves in which the suction port and the working port are connected in parallel to the fluid circuit, and the proximal end is pivotally attached and the magnet is provided at the distal end. Locations where the levers that are fixed and urged by the spring toward the main valve side of the flow path switching valve are arranged facing the main valve respectively, and that the lever is rotated by the movement of the main valve and is sensed by the magnet at the tip of the lever. It is a double valve for press with a magnetically sensitive switch installed in it, and an electric variable timing circuit is connected between the flow path switching valve solenoid and the start switch, so it is compact, inexpensive, and highly reliable with no false detection. Therefore, it is possible to deal with future trends in automation equipment with fault diagnosis.

Further, according to the present invention, the timing adjustment time can be continuously adjusted without being influenced by the orifice diameter by machining, which facilitates the adjustment of the press machine. Further, according to the present invention, since the orifice is not present in the air passage and it is not affected by the air quality, the press machine operates stably.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a non-operating state of a specific example of a monitor device for a double valve for a press according to the present invention.

FIG. 2 is a side view in which a part of FIG. 1 is sectioned.

FIG. 3 is a sectional view taken along the line III-III in FIG.

FIG. 4 is a cross-sectional view showing a state at the time of malfunction of FIG.

FIG. 5 is a symbol view of a timing adjusting device for a double valve for a press according to the present invention.

FIG. 6 is a symbol diagram of a conventional monitor device for a double valve for a press.

FIG. 7 is a symbol diagram of a conventional timing adjusting device for a clutch of a double valve for a press.

FIG. 8 is a symbol diagram of a conventional brake timing adjusting device for a double valve for a press.

[Explanation of symbols]

P ... Suction port A ... Actuating port 16/16 '... Magnet 18/18' ... Spring 2.2 '... Main valve 12/12' ... Lever 20/20 '... Magnetically sensitive switch SOL ₁ / SOL ₁ ' ... Solenoid SOL ₃₁ / SOL ₃₁ '… Solenoid 32… Start switch 33… Electric variable timing circuit

Claims (1)

[Scope of utility model registration request] 1. A double valve for a press having two flow path switching valves in which an intake port and an operating port are connected in parallel to a fluid circuit, in which a base end is pivotally attached and a magnet is fixedly attached to a tip end to flow by a spring. A lever urged to the main valve side of the path switching valve is arranged so as to face the main valve, and a magnetically sensitive switch is installed at a position where the lever tip magnet causes rotation by rotation of the main valve. A dual valve for presses that has an electric variable timing circuit connected between the flow path switching valve solenoid and the start switch.