JP2022070433A - Door opening/closing device of machine tool - Google Patents

Abstract

To reduce an impact when a door of a machine tool driven by a hydraulic cylinder stops in an open position or in a closed position.SOLUTION: A door opening/closing device 10 of a machine tool which drives a door by a hydraulic cylinder 90 includes a fluid pressure source 12, a door opening/closing control valve 16 which controls a direction of a working fluid supplied to the hydraulic cylinder, speed control valve assemblies 24, 30 which restrict a speed of opening operation or closing operation of the door, cushioning adjustment valves 26, 32 which are arranged parallel to the speed control valve assemblies and have higher throttle strength than the speed control valve assemblies 24, 30, cushioning operation valves 22, 28 which switch distribution of the working fluid between the speed control valve assemblies and the cushioning adjustment valves 26, 32, and a control device 50 which controls the cushioning operation valves 22, 28 so that the fluid is distributed in the cushioning adjustment valves 26, 32 after the working fluid is distributed in the speed control valve assemblies 24, 30 when the opening operation or closing operation of the door starts, and a previously-set cushioning operation start time passes from a start of the opening operation or closing operation of the door.SELECTED DRAWING: Figure 2

Description

The present invention relates to a door opening / closing device for opening / closing the door of a machine tool such as an ATC shutter or an operator door.

A slide that closes an opening formed in the partition wall between the machining chamber and the tool storage chamber to transport tools between the machining chamber and the tool storage chamber when changing tools in a machine tool door, for example, a machining center. The door or ATC shutter of the formula is driven by a fluid pressure cylinder, for example a pneumatic cylinder.

Recently, in order to shorten the processing time, the opening and closing operation of the door tends to be faster and faster, and therefore, it is more necessary to cushion the mechanical impact at the end point of the moving stroke. Patent Document 1 describes a transfer speed control device in which a self-timer type two-speed control unit is provided between a fluid pressure source and a port of a pneumatic cylinder to cushion such an impact. There is.

Japanese Patent Application Laid-Open No. 02-031002

Generally, the cylinder and piston of a fluid pressure cylinder with a cushioning function that cushions impact are sealed by a sealing member such as packing. Sealing performance deteriorates due to wear due to friction. Therefore, in the moving speed control device described in Patent Document 1, the cushioning effect cannot be obtained due to deterioration or wear of the sealing member.

The present invention has a technical problem of solving the problems of the prior art, and is designed to alleviate the impact when the door of the machine tool driven by the fluid pressure cylinder is stopped in the open position or the closed position. It is intended to provide a door opening / closing device.

In order to achieve the above object, according to the present invention, in the door opening / closing device of a machine tool that drives a door with a fluid pressure cylinder, the supply direction of the working fluid supplied from the fluid pressure source to the fluid pressure cylinder is controlled. A door open / close control valve for opening or closing the door, and a predetermined throttle provided in the fluid supply circuit or discharge circuit of the fluid pressure cylinder to regulate the speed of the door opening or closing operation. A high-strength speed control valve assembly, a buffer control valve provided in parallel with the speed control valve assembly and having a higher throttle strength than the speed control valve assembly, and the speed control valve assembly. The buffer actuating valve for switching the flow of the working fluid between the buffer adjusting valve and the door opening / closing control valve are controlled so that the door is opened or closed, and the door is opened or closed. At the start, the working fluid flows through the speed control valve assembly, and after a preset buffering operation start time elapses from the start of the opening or closing operation of the door, the fluid flows through the buffering control valve. , A door opening / closing device for a machine tool provided with a control device for controlling the buffer actuating valve.

According to the present invention, the cushioning operation valve is operated not by the position of the door but by the time after the opening / closing operation of the door is started (buffering operation start time). Even if a sealing member for a cushion function is not used for the fluid pressure cylinder, an appropriate cushioning effect or cushioning effect can be exhibited.

It is a schematic front view which shows an example of the machine tool provided with the door opening / closing device of this invention. It is a block diagram of the door opening / closing device according to 1st Embodiment of this invention. It is a block diagram of the door opening / closing device according to the 2nd Embodiment of this invention. It is a flowchart for demonstrating the compensation method of a decrease in a buffering effect.

Hereinafter, the first embodiment of the present invention will be described with reference to the accompanying drawings.
First, referring to FIG. 1 showing an example of a machine tool to which the present invention is applied, the machine tool 100 constitutes a horizontal machining center. The machine tool 100 includes a bed 102 as a base fixed to the floor of the factory. A pair of Z-axis guide rails 102b extend in the front-rear direction or the Z-axis direction (direction perpendicular to the paper surface in FIG. 1) in the front portion of the upper surface of the bed 102, and are extended along the Z-axis guide rails 102b. The Z-axis slider 112 is provided so as to be reciprocating. A table 114 to which the work W is attached is mounted on the upper surface of the Z-axis slider 112.

A pair of X-axis guide rails 102a extend in the left-right direction or the X-axis direction (left-right direction in FIG. 1) behind the Z-axis slider 112 on the upper surface of the bed 102, and are along the X-axis guide rails 102a. The column 104 is provided so as to be able to reciprocate.

A Y-axis guide rail 104a extends vertically or in the Y-axis direction on the front surface of the column 104, and a Y-axis slider 106 is provided so as to be reciprocating along the Y-axis guide rail 104a. The Y-axis slider 106 is equipped with a spindle head 108 that rotatably supports the spindle 110 about a horizontal central axis. The spindle head 108 can include a spindle motor (not shown) that rotationally drives the spindle 110.

Further, the machine tool 100 includes an X-axis feed device (not shown) that drives the column 104 in the X-axis direction, a Y-axis feed device (not shown) that drives the Y-axis slider 106 in the Y-axis direction, and a Z-axis. It is equipped with a Z-axis feed device (not shown) that drives the slider 112 in the Z-axis direction. The X-axis, Y-axis, and Z-axis feeders are a ball screw (not shown) extending in each direction of the X-axis, Y-axis, and Z-axis, and a servo motor connected to one end of each ball screw (Fig.). A nut (not shown) that engages with the ball screw is attached to the column 104, the Y-axis slider 106, and the Z-axis slider 112.

The horizontal machining center configured by the machine tool 100 further includes a tool magazine 120 for storing a plurality of tools required for machining by the machine tool 100, one of the tools stored in the tool magazine 120, and a spindle 110 of the machine tool 100. A tool changing device 140 for exchanging the tool T attached to the tip is provided. The machine tool 100, the tool magazine 120 and the tool changer 140 are surrounded by a cover 130.

The cover 130 includes a partition wall 132 that divides the inside thereof into a processing chamber 134 and a tool storage chamber 136. The machine tool 100 is arranged in the machining chamber 134 for machining the work, and the tool magazine 120 and the tool changing device 140 are arranged in the tool accommodating chamber 136. The partition wall 132 is formed with an opening 132a for moving a tool between the processing chamber 134 and the tool accommodating chamber 136, and the partition wall 132 opens and closes the opening 132a as an example of a machine tool door. A shutter 138 for the function is arranged. The shutter 138 is reciprocated in the horizontal direction by a pneumatic cylinder 90 as a fluid pressure cylinder. The pneumatic cylinder 90 is preferably arranged in the tool storage chamber.

The tool magazine 120 includes a base member 122 formed in a disk shape. The base member 122 has a receiving portion 124 which is open outward in the radial direction and is composed of a plurality of recesses arranged at equal angular intervals in the circumferential direction, and each of the receiving portions 124 has a receiving portion 124 via a tool holder 126. The tool is held. The tool magazine 120 is supported by a horizontally held rotation shaft 120a so as to rotate in a vertical plane to a support structure such as a frame (not shown). The rotary shaft 120a is coupled to an output shaft of a magazine drive motor (not shown) that rotationally drives the tool magazine 120.

The tool changing device 140 is arranged between the tool magazine 120 and the machine tool 100, and includes a changing arm 142 and a shifter 144. Grippers 142a and 142b for gripping tools are provided at both ends of the replacement arm 142. The exchange arm 142 can perform a linear operation of moving forward and backward in the direction of the rotation axis of the spindle 110 and a rotation operation of rotating 90 ° or 180 ° in a plane (vertical plane) perpendicular to the rotation axis of the spindle 110. There is.

The shifter 144 is provided so as to be able to reciprocate in the horizontal direction between the tool magazine 120 and the replacement arm 142. The shifter 144 receives the tool at the standby position 121 of the tool magazine 120 from the tool magazine 120, and transfers the tool to the tool transfer position 146. On the contrary, the shifter 144 receives the tool from the exchange arm 142 at the tool transfer position 146, and attaches the tool to the receiving portion 124 of the tool magazine 120 arranged at the standby position 121.

Further, the machine tool 100 includes an NC device (not shown) that controls a servomotor and a spindle motor of each of the X-axis, Y-axis, and Z-axis feed devices, a tool magazine 120, and a tool changer 140 based on a machining program. , A machine control device (not shown) that controls peripheral equipment such as a coolant supply device that supplies coolant to the machine tool 100 is provided.

Next, with reference to FIG. 2, the opening / closing device of the shutter 138 will be described as an example of the door opening / closing device of the machine tool of the present invention.
The shutter opening / closing device 10 includes a fluid pressure circuit that drives the shutter 138 as a door, and a control device 50 that controls the fluid pressure circuit. In the present embodiment, the fluid pressure circuit is a first and first speed control valve assembly that regulates the opening / closing speed of the pneumatic source 12 as a working fluid source, the directional control valve 16 as a door opening / closing control valve, and the shutter 138. 2 speed controllers 24, 30, first and second proportional valves 26, 32 as buffer regulating valves, first and second switching valves 22, 28 as buffer working valves, pneumatic cylinder 90 and control device 50. Is provided as a main component.

The pneumatic cylinder 90 as a fluid pressure cylinder for driving the shutter 138 includes a piston 90b reciprocally arranged in the cylinder 90a and a piston rod 90c coupled to the piston 90b. The pneumatic cylinder 90 is a double-acting cylinder, and the inside of the cylinder is airtightly divided into a head-side pressure chamber and a rod-side pressure chamber by the piston 90b, and the shutter 138 is opened and closed by the reciprocating movement of the piston 90b. ..

As an example, the pneumatic cylinder 90 is arranged in the tool storage chamber 136 by fixing the cylinder 90a to a stationary member in the tool storage chamber 136, for example, the partition wall 132 of the cover 130, and attaching the piston rod 90c to the shutter 138. Can be fixed.

The pneumatic source 12 can include a compressor, a tank, a pressure regulating valve, and the like. The pneumatic source 12 is connected to the directional control valve 16 via the pressure supply line 14. In the present embodiment, the directional control valve 16 is a 3-position 5-port solenoid valve having first and second solenoids 16a and 16b. The directional control valve 16 moves to the first position by urging the first solenoid 16a, and moves to the second position by urging the second solenoid 16b.

The pressure supply line 14 is connected to the first and second lines 18 and 20 via the directional control valve 16. The first pipeline 18 is connected to the head-side pressure chamber of the pneumatic cylinder 90, and the second pipeline 20 is connected to the rod-side pressure chamber of the pneumatic cylinder 90. In the present embodiment, by supplying pressurized air as a pressure fluid to the pressure chamber on the head side and exhausting the pressurized air from the pressure chamber on the rod side, the piston rod 90c is extended and the shutter 138 is opened, and conversely. By supplying pressurized air to the pressure chamber on the rod side and exhausting the pressurized air from the pressure chamber on the head side, the piston rod 90c contracts and the shutter 138 closes.

A first speed controller 24 is arranged in the first pipeline 18. The first speed controller 24 includes a throttle 24a and a check valve 24b that allows the flow of pressurized air from the directional control valve 16 toward the pneumatic cylinder 90. The throttle 24a and the check valve 24b are connected to the first pipeline 18 in parallel with each other. In the illustrated embodiment, the throttle 24a is a throttle valve, but it may be a simple orifice. The valve opening or orifice size of the throttle 24a is preset so that the shutter 138 can move at an appropriate speed when the shutter 138 is opened.

A first proportional valve 26 having a proportional solenoid 26a is further arranged in the first pipeline 18. The first proportional valve 26 is connected to the first pipeline 18 in parallel with the first speed controller 24. The first proportional valve 26 can change the valve opening degree between 0 and 100% by changing the current value supplied to the proportional solenoid 26a. The first proportional valve 26 moves to a closed position where the valve opening is 0% by deenergizing the proportional solenoid 26a, and moves to an open position where the valve opening is variable by urging the proportional solenoid 26a. Moving. When in the open position, the first proportional valve 26 throttles the working fluid (pressurized air) flowing therein to be stronger than the throttle 24a, i.e., to provide higher flow path resistance than the throttle 24a. Position or valve opening degree, that is, the current value supplied to the proportional solenoid 26a is set.

A first switching valve 22 having a solenoid 22a is further arranged in the first pipeline 18. The first switching valve 22 is arranged between the first speed controller 24, the first proportional valve 26, and the directional control valve 16.

A second speed controller 30 is arranged in the second pipeline 20. The second speed controller 30 includes a throttle 30a and a check valve 30b that allows the flow of pressurized air from the directional control valve 16 toward the pneumatic cylinder 90. The throttle 30a and the check valve 30b are connected to the second pipeline 20 in parallel with each other. In the illustrated embodiment, the throttle 30a is a throttle valve, but it may be a simple orifice. The valve opening or orifice size of the diaphragm 30a is preset so that the shutter 138 can move at an appropriate speed when the shutter 138 is closed.

A second proportional valve 32 having a proportional solenoid 32a is further arranged in the second pipeline 20. The second proportional valve 32 is connected to the second pipeline 20 in parallel with the second speed controller 30. The second proportional valve 32 can change the valve opening degree between 0 and 100% by changing the current value supplied to the proportional solenoid 32a. The second proportional valve 32 moves to a closed position where the valve opening is 0% by deenergizing the proportional solenoid 32a, and moves to an open position where the valve opening is variable by urging the proportional solenoid 32a. Moving. When in the open position, the second proportional valve 32 throttles the working fluid (pressurized air) flowing therein to be stronger than the throttle 30a, i.e., to provide higher flow path resistance than the throttle 30a. Position or valve opening degree, that is, the current value supplied to the proportional solenoid 32a is set.

A second switching valve 28 having a solenoid 28a is further arranged in the second pipeline 20. The second switching valve 28 is arranged between the second speed controller 30, the second proportional valve 32, and the second switching valve 28.

The first and second switching valves 22 and 28 can be configured by a solenoid-type two-position, three-port switching valve. When the solenoid 22a of the first switching valve 22 is deenergized and is in the first position shown, the first speed controller 24 communicates with the directional control valve 16 and the first proportional valve 26 communicates with the directional control valve 16. Fluidly separated from. When the solenoid 22a is urged and the first switching valve 22 moves from the first position to the second position, the first speed controller 24 is fluidly separated from the directional control valve 16 and the first proportional valve. 26 communicates with the directional control valve 16.

Similarly, when the second switching valve 28 is in the first position shown, the second speed controller 30 communicates with the directional control valve 16 and the second proportional valve 32 is fluid from the directional control valve 16. Is separated into. When the solenoid is urged and the second switching valve 28 moves from the first position to the second position, the second speed controller 30 is fluidly separated from the directional control valve 16 and the second proportional valve 32 becomes. It communicates with the directional control valve 16.

The shutter opening / closing device 10 further includes first and second proximity switches 38 and 40. The first proximity switch 38 is arranged in the partition wall 132 of the cover 130 at a position where the open position where the shutter 138 is completely open can be detected. The second proximity switch 40 is arranged in the partition wall 132 at a position where the closed position where the shutter 138 is completely closed can be detected.

The control device 50 includes a timer 52, a buffer control unit 54 electrically connected to the solenoids 22a and 28a of the first and second switching valves 22 and 28, and the first and second solenoids 16a of the directional control valve 16. The open / close control unit 56 electrically connected to 16b, the throttle setting unit 58 electrically connected to the proportional solenoids 26a and 32a of the first and second proportional valves 26 and 32, the storage unit 60 and the input unit 62 are provided. I have.

The timer 52, the buffer control unit 54, the open / close control unit 56, the aperture setting unit 58, the storage unit 60, and the input unit 62 are such as a CPU (central processing unit), RAM (random access memory), and ROM (read-only memory). An RTC (Real-Time-Clock) consisting of a memory device, a storage device such as an HDD (hard disk drive) or SSD (solid state drive), an input / output port, and an integrated circuit equipped with a clock function, and interconnecting these. It can consist of a computer including a two-way bus and related software. It may be configured by software as a part of the NC device or the machine control device of the machine tool 100.

The timer 52 is connected to the first and second proximity switches 38 and 40, and is the opening time of the shutter 138, which is the operating time of the shutter 138 from the closed position to the open position, and the opening time from the open position to the closed position. The closing time, which is the operating time of the shutter 138, is measured. The measurement result is stored in the storage unit 60.

The storage unit 60 stores in advance a reference value that defines the operation of the shutter opening / closing device 10. The reference values are at least (1) the reference operating time To-ref for the shutter 138, (2) the initial value of the buffering operation start time for the buffering operation valve, and (3) the reference buffering operation for the buffering operation valve. The start time Tcu-ref, (4) the initial value of the valve opening for the buffer adjusting valve, and (5) the reference valve opening Ov-ref for the buffer adjusting valve are included.

The input unit 62 receives commands (magazine shutter open command, magazine shutter close command) related to the opening / closing operation of the shutter 138 described in the machining program read and interpreted by the NC device of the machine tool 100. When the control device 50 is independent of the NC device, the command can be input from the NC device. When the control device 50 is configured as a part of the NC device, the command can be input from the reading / interpreting unit (not shown) of the NC device.

Hereinafter, the operation of this embodiment will be described.
When the magazine shutter open command is input to the input unit 62, the open / close control unit 56 urges the first solenoid 16a of the directional control valve 16. As a result, the directional control valve 16 moves to the first position, the first pipeline 18 communicates with the pneumatic source 12, and the second pipeline 20 communicates with the silencer 34. At this time, the buffer control unit 54 holds the first and second switching valves 22 and 28 in the first position, and the throttle setting unit 58 is in a state where the first and second proportional valves 26 and 32 are closed. To maintain.

In this way, the pressurized air from the pneumatic source 12 passes through the check valve 24b of the first speed controller 24 and is supplied into the head side pressure chamber of the pneumatic cylinder 90, and the rod side pressure of the pneumatic cylinder 90. The pressurized air in the room passes through the second throttle 30a of the second speed controller 30 and is exhausted from the silencer 34. As a result, the piston rod extends, and the shutter 138 starts the opening operation from the closed position.

Next, when a predetermined time (buffer operation start time Tcu) elapses after the shutter 138 starts the opening operation, the buffer control unit 54 urges the solenoid 28a to press the second switching valve 28 to the second. Move to position. The buffering operation start time Tcu is stored in the storage unit 60 in advance in, for example, 0.3 to 0.5 seconds as an initial value. The timer 52 measures the passage of time from the time when the open / close control unit 56 urges the first solenoid 16a of the direction control valve 16, and when the buffer operation start time Tcu elapses, the throttle setting unit 58 becomes the first. The proportional solenoid 32a of the proportional valve 32 of 2 is urged, and the buffer control unit 54 urges the solenoid 28a of the second switching valve 28.

When the proportional solenoid 32a of the second proportional valve 32 is urged, the second proportional valve 32 opens the valve opening position determined according to the preset supply current value to the proportional solenoid 32a. Move to. Further, when the solenoid 28a of the second switching valve 28 is urged and the second switching valve 28 moves to the second position, the second throttle 30a of the second speed controller 30 is fluid from the silencer 34. The second proportional valve 32 communicates with the silencer 34, and the pressurized air in the rod-side pressure chamber of the pneumatic cylinder 90 is exhausted through the second proportional valve 32. .. As described above, since the second proportional valve 32 is set to throttle the working fluid (pressurized air) flowing therethrough more strongly than the second throttle 30a, the movement of the piston in the pneumatic cylinder 90 The speed is reduced and at the end of the stroke, the piston is prevented from colliding with the inner wall of the cylinder at high speed, providing a cushioning effect.

When the first proximity switch 38 detects that the shutter 138 has reached the open position, the open / close control unit 56 deactivates the first solenoid 16a of the directional control valve 16. As a result, the directional control valve 16 returns to the neutral position shown in the figure, and the shutter 138 is held in the open position. At the same time, the buffer control unit 54 deactivates the solenoid 28a of the second switching valve 28.

When the tool change operation is completed and the magazine shutter closing command is input to the input unit 62, the open / close control unit 56 urges the second solenoid 16b of the directional control valve 16. As a result, the directional control valve 16 moves to the second position. In this way, pressurized air from the pneumatic source 12 passes through the check valve 30b of the second speed controller 30 and is supplied to the rod-side pressure chamber of the pneumatic cylinder 90. At the same time, the pressurized air in the pressure chamber on the head side passes through the throttle 24a of the first speed controller 24 and is exhausted from the silencer 36. As a result, the piston rod contracts, and the shutter 138 starts the closing operation from the open position. In this way, the fluid pressure circuit of the shutter opening / closing device 10 controls the opening / closing operation of the shutter 138 by meter-out control.

Next, when the buffer operation start time Tcu elapses after the shutter 138 starts the closing operation, the aperture setting unit 58 urges the proportional solenoid 26a of the first proportional valve 26, and the buffer control unit 54 sets the first. The solenoid 22a of the switching valve 22 of 1 is urged to move the first switching valve 22 to the second position. The buffering operation start time Tcu may be the same value or a different value for the opening operation and the closing operation of the shutter 138.

The timer 52 measures the passage of time from the time when the open / close control unit 56 urges the first solenoid 16a of the direction control valve 16, and when the buffer operation start time Tcu elapses, the throttle setting unit 58 becomes the first. The proportional solenoid 26a of the proportional valve 26 of 1 is urged, and the buffer control unit 54 urges the solenoid 28a of the second switching valve 28.

When the proportional solenoid 26a of the first proportional valve 26 is urged, the first proportional valve 26 opens the valve opening position determined according to the preset supply current value to the proportional solenoid 26a. Move to. Further, when the first switching valve 22 moves to the second position, the first throttle 24a of the first speed controller 24 is fluidly separated from the silencer 36, and the first proportional valve 26 silences. The pressurized air in the pressure chamber on the head side of the pneumatic cylinder 90, which communicates with the vessel 36, is exhausted through the first proportional valve 26. As described above, since the first proportional valve 26 is set to throttle the working fluid (pressurized air) flowing therethrough more strongly than the first throttle 24a, the movement of the piston in the pneumatic cylinder 90 The speed is reduced and a cushioning effect is produced.

When the second proximity switch 40 detects that the shutter 138 has reached the closed position, the open / close control unit 56 deactivates the second solenoid 16b of the directional control valve 16. As a result, the directional control valve 16 returns to the neutral position shown in the figure, and the shutter 138 is held in the closed position. At the same time, the buffer control unit 54 deactivates the solenoid 22a of the first switching valve 22.

Next, a second embodiment of the shutter opening / closing device will be described with reference to FIG.
The shutter opening / closing device 200 according to the second embodiment includes a fluid pressure circuit for driving the shutter 138 and a control device 70 for controlling the fluid pressure circuit. In the present embodiment, the fluid pressure circuit is a speed control valve that regulates the opening / closing speed of the pneumatic source 12 as the working fluid source, the directional control valve 202 as the door opening / closing control valve, and the shutter 138 as in the embodiment of FIG. A throttle 206 as an assembly, a proportional valve 208 as a shock absorber, a switching valve 204 as a shock absorber, a pneumatic cylinder 90 as a fluid pressure cylinder for driving the shutter 138 as in the embodiment of FIG. 2, and The control device 70 is provided as a main component.

The pneumatic source 12 is connected to the directional control valve 202 via the pressure supply line 14. In the present embodiment, the directional control valve 202 is a 3-position 4-port solenoid valve having first and second solenoids 202a and 202b. The directional control valve 202 moves to the first position by urging the first solenoid 202a, and moves to the second position by urging the second solenoid 202b.

The pressure supply pipe line 14 is connected to the first pipe line 18 connected to the head side pressure chamber of the pneumatic cylinder 90 and the rod side pressure chamber of the pneumatic cylinder 90 via the directional control valve 202. It is connected to the pipeline 20 of 2. Also in this embodiment, the piston rod 90c is extended and the shutter 138 is opened by supplying the pressurized air as the pressure fluid to the pressure chamber on the head side and exhausting the pressurized air from the pressure chamber on the rod side. By supplying pressurized air to the pressure chamber on the rod side and exhausting the pressurized air from the pressure chamber on the head side, the piston rod 90c contracts and the shutter 138 closes.

An exhaust pipe line 210 is also connected to the directional control valve 202. When the first solenoid 202a is urged and the directional control valve 202 is in the first position, the first pipeline 18 communicates with the pressure supply pipeline 14 and the second pipeline 20 is the exhaust pipeline. Connected to 210. When the second solenoid 202b is urged and the directional control valve 202 is in the second position, the first line 18 is connected to the exhaust line 210 and the second line 20 is the pressure supply line. Connected to 14.

The exhaust pipe line 210 is connected to the first and second exhaust pipe lines 212 and 214 via the switching valve 204. A throttle 206 is arranged in the first exhaust pipe line 212, and a proportional valve 208 is arranged in the second exhaust pipe line 214. The first and second exhaust pipes 212 and 214 rejoin the throttle 206 and downstream of the proportional valve 208 and are connected to the silencer 216.

In FIG. 3, the throttle 206 is a throttle valve, but it may be a simple orifice. The valve opening or orifice size of the aperture 206 is preset so that the shutter 138 can move at an appropriate speed when the shutter 138 is opened.

The proportional valve 208 can change the valve opening degree between 0 and 100% by changing the current value supplied to the proportional solenoid 208a. The proportional valve 208 moves to a closed position where the valve opening degree is 0% by deenergizing the proportional solenoid 208a, and moves the valve opening position to an open position by urging the proportional solenoid 208a. When in the open position, the proportional valve 208 throttles the working fluid (pressurized air) flowing through it more strongly than the throttle 206, i.e., its spool position or so as to provide higher flow path resistance than the throttle 206. The valve opening degree, that is, the current value supplied to the proportional solenoid 208a is set.

The switching valve 204 can be configured by a solenoid type 2-position 3-port switching valve. When the solenoid 204a of the switching valve 204 is deenergized and in the first position shown, the throttle 206 communicates with the directional control valve 202 and the proportional valve 208 is fluidly separated from the directional control valve 202. When the solenoid 204a is urged and the switching valve 204 moves from the first position to the second position, the throttle 206 is fluidly separated from the directional control valve 16 and the proportional valve 208 communicates with the directional control valve 202.

Like the shutter opening / closing device 10, the shutter opening / closing device 200 also includes first and second proximity switches 38 and 40. The first proximity switch 38 is arranged in the partition wall 132 of the cover 130 at a position where the open position where the shutter 138 is completely open can be detected. The second proximity switch 38 is arranged in the partition wall 132 at a position where the closed position where the shutter 138 is completely closed can be detected.

Similar to the control device 50, the control device 70 is electrically connected to the timer 72, the buffer control unit 74 electrically connected to the solenoid 204a of the switching valve 204, and the first and second solenoids 202a and 202b of the directional control valve 202. It includes an open / close control unit 76 connected to the vehicle, a throttle setting unit 78 electrically connected to the proportional solenoid 208a of the proportional valve 208, a storage unit 80, and an input unit 82.

The timer 72, the buffer control unit 74, the open / close control unit 76, the aperture setting unit 78, the storage unit 80, and the input unit 82 are such as a CPU (central processing unit), RAM (random access memory), and ROM (read-only memory). An RTC (Real-Time-Clock) consisting of a memory device, a storage device such as an HDD (hard disk drive) or SSD (solid state drive), an input / output port, and an integrated circuit equipped with a clock function, and interconnecting these. It can consist of a computer including a two-way bus and related software. It may be configured by software as a part of the NC device or the machine control device of the machine tool 100.

The timer 72 is connected to the first and second proximity switches 38 and 40, and is the opening time of the shutter 138, which is the operating time of the shutter 138 from the closed position to the open position, and the opening time from the open position to the closed position. The closing time, which is the operating time of the shutter 138, is measured. The measurement result is stored in the storage unit 80.

Similar to the storage unit 60, the storage unit 80 stores in advance a reference value that defines the operation of the shutter opening / closing device 200. The reference values are at least (1) the reference operating time To-ref for the shutter 138, (2) the initial value of the buffering operation start time for the buffering operation valve, and (3) the reference buffering operation for the buffering operation valve. The start time Tcu-ref, (4) the initial value of the valve opening for the buffer adjusting valve, and (5) the reference valve opening Ov-ref for the buffer adjusting valve are included.

The input unit 82 receives commands (magazine shutter open command, magazine shutter close command) related to the opening / closing operation of the shutter 138 described in the machining program read and interpreted by the NC device of the machine tool 100. When the control device 70 is independent of the NC device, the command can be input from the NC device. When the control device 70 is configured as a part of the NC device, the above command can be input from the reading / interpreting unit (not shown) of the NC device.

Hereinafter, the operation of this embodiment will be described.
When the magazine shutter open command is input to the input unit 82, the open / close control unit 76 urges the first solenoid 202a of the directional control valve 202. As a result, the directional control valve 202 moves to the first position, the first pipeline 18 communicates with the pneumatic source 12, and the second pipeline 20 communicates with the exhaust pipeline 210. At this time, the buffer control unit 74 holds the switching valve 204 in the first position, and the throttle setting unit 78 keeps the proportional valve 208 in a closed state.

In this way, the pressurized air from the pneumatic source 12 is supplied to the pressure chamber on the head side of the pneumatic cylinder 90, and the pressurized air in the pressure chamber on the rod side of the pneumatic cylinder 90 passes through the throttle 206 and is a silencer. It is exhausted from 216. As a result, the piston rod extends, and the shutter 138 starts the opening operation from the closed position.

Next, when a predetermined time (buffer operation start time Tcu) elapses after the shutter 138 starts the opening operation, the buffer control unit 74 urges the solenoid 204a to move the switching valve 204 to the second position. Let me. The buffering operation start time Tcu is stored in the storage unit 80 in advance in, for example, 0.3 to 0.5 seconds as an initial value. The timer 72 measures the passage of time from the time when the open / close control unit 76 urges the first solenoid 202a of the direction control valve 202, and when the buffer operation start time Tcu elapses, the throttle setting unit 78 is proportional. The proportional solenoid 208a of the valve 208 is urged, and the buffer control unit 74 urges the solenoid 204a of the switching valve 204.

When the proportional solenoid 208a of the proportional valve 208 is urged, the proportional valve 208 moves to an open position of the valve opening degree determined according to the preset supply current value to the proportional solenoid 208a. Further, when the switching valve 204 moves to the second position, the throttle 206 is fluidly separated from the exhaust pipe line 210, and the proportional valve 208 communicates with the exhaust pipe line 210, so that the pressure on the rod side of the pneumatic cylinder 90 is increased. The pressurized air in the room will be exhausted through the proportional valve 208. As described above, since the proportional valve 208 is set to throttle the working fluid (pressurized air) flowing therethrough more strongly than the throttle 206, the moving speed of the piston in the pneumatic cylinder 90 is reduced and buffered. It works.

When the first proximity switch 38 detects that the shutter 138 has reached the open position, the open / close control unit 76 deactivates the first solenoid 202a of the directional control valve 202. As a result, the directional control valve 202 returns to the neutral position shown in the figure, and the shutter 138 is held in the open position. At the same time, the buffer control unit 74 deactivates the solenoid 204a of the switching valve 204.

When the tool change operation is completed and the magazine shutter closing command is input to the input unit 82, the open / close control unit 76 urges the second solenoid 202b of the directional control valve 202. As a result, the directional control valve 202 moves to the second position. In this way, pressurized air is supplied from the pneumatic source 12 to the rod-side pressure chamber of the pneumatic cylinder 90. At the same time, the pressurized air in the pressure chamber on the head side passes through the throttle 206 and is exhausted from the silencer 216. As a result, the piston rod contracts, and the shutter 138 starts the closing operation from the open position. In this way, the fluid pressure circuit of the shutter opening / closing device 200 controls the opening / closing operation of the shutter 138 by meter-out control.

Next, when the buffer operation start time Tcu elapses after the shutter 138 starts the closing operation, the throttle setting unit 78 urges the proportional solenoid 208a of the proportional valve 208, and the buffer control unit 74 uses the solenoid of the switching valve 204. It is designed to urge 204a. The buffering operation start time Tcu may be the same value or a different value for the opening operation and the closing operation of the shutter 138.

The timer 72 measures the passage of time from the time when the open / close control unit 76 urges the second solenoid 202b of the direction control valve 202, and when the buffer operation start time Tcu elapses, the throttle setting unit 78 is proportional. The proportional solenoid 208a of the valve 208 is urged, and the cushioning control unit 74 urges the solenoid 204a of the switching valve 204.

When the proportional solenoid 208a of the proportional valve 208 is urged, the proportional valve 208 moves to an open position of the valve opening degree determined according to the preset supply current value to the proportional solenoid 208a. Further, when the switching valve 204 moves to the second position, the throttle 206 is fluidly separated from the exhaust pipe line 210, and the proportional valve 208 communicates with the exhaust pipe line 210, so that the pressure on the head side of the pneumatic cylinder 90 is increased. The pressurized air in the room will be exhausted through the proportional valve 208. As described above, since the proportional valve 208 is set to throttle the working fluid (pressurized air) flowing therethrough more strongly than the throttle 206, the moving speed of the piston in the pneumatic cylinder 90 is reduced and buffered. It works.

When the second proximity switch 40 detects that the shutter 138 has reached the closed position, the open / close control unit 76 deactivates the second solenoid 202b of the directional control valve 202. As a result, the directional control valve 202 returns to the neutral position shown in the figure, and the shutter 138 is held in the closed position. At the same time, the buffer control unit 74 deactivates the solenoid 204a of the switching valve 204.

In a fluid pressure cylinder such as the pneumatic cylinder 90, the seal member wears over time. In particular, in the case of a machine tool as shown in FIG. 1, in order to shorten the time required for tool replacement, the shutter 138 is conventionally controlled to move at high speed, and therefore the pneumatic cylinder 90 also operates at high speed. The О ring that seals between the outer peripheral surface of the piston and the inner peripheral surface of the cylinder and between the piston rod and the cylinder wears over time, and the frictional resistance between the outer peripheral surface of the piston and the inner peripheral surface of the cylinder gradually increases. descend. Therefore, the moving speed of the piston increases with time, and accordingly, the time required for opening and closing the shutter 138 is gradually shortened, and the cushioning effect is reduced.

Therefore, in the present invention, the aged deterioration of the fluid pressure actuator or the fluid pressure cylinder (pneumatic cylinder 90) for driving the shutter 138, particularly the decrease in the cushioning effect due to the wear of the seal member or the O-ring is automatically compensated or corrected. It has become.

An example of a method for compensating for a decrease in the buffering effect will be described with reference to FIG.
The buffer control unit 54 measures the operating time of the shutter 138. While repeating the opening / closing operation of the shutter 138, the buffer control unit 54 measures the opening time and closing time of the shutter 138 based on the signals from the proximity switches 38 and 40, and averages them to average the shutter opening / closing time Toc. -Ave is obtained (step S10). The average shutter opening / closing time Toc-ave can be, for example, the average value of 10 opening / closing times. Only the opening time or closing time of the shutter 138 may be used, that is, the average shutter opening time or the average shutter closing time may be used as the operating time of the shutter 138.

Next, the average shutter opening / closing time Toc-ave of the shutter 138 is compared with the reference operating time To-ref stored in the storage unit 60 (step S12). When the average shutter opening / closing time Toc-ave is equal to or longer than the reference operating time To-ref, this buffering action compensation routine ends (step S18).

If the average shutter opening / closing time Toc-ave is smaller than the reference operation time To-ref (No in step S12), is the current buffer operation start time Tcu-pre equal to or greater than the reference buffer operation start time Tcu-ref? Whether or not it is determined (step S14). When the current buffering operation start time Tcu-pre is equal to or greater than the reference buffering operation start time Tcu-ref (Yes in step S14), the current buffering operation start time Tcu-pre is advanced by a predetermined time ΔTcu (step S16). .. That is, the solenoid of the buffer actuating valve (first and second switching valves 22, 28 in the first embodiment, switching valve 204 in the second embodiment) (solenoids 22a, 28a, second in the first embodiment). In the embodiment of the above, the timing of urging the solenoid 204a) is earlier. As an example, ΔTcu = 0.01 seconds can be set.

If the current buffering operation start time Tcu-pre is smaller than the reference buffering operation start time Tcu-ref (No in step S14), an alert is generated (step S20). This alert is a precaution for preventive maintenance of the seal member of the pneumatic cylinder 90, especially the O-ring replacement. As an example, an alert may be generated by turning on a lamp (not shown) attached to the control panel (not shown) of the machine tool 100 or displaying it on the display (not shown) of the control panel. can. Alternatively, the alert may be generated acoustically. As a result, the operator of the machine tool 100 is notified that the replacement time of the O-ring is approaching.

Next, the current valve opening Ov-pre of the buffer regulating valve at this time (the first and second proportional valves 26 and 32 in the first embodiment and the proportional valve 208 in the second embodiment) is the reference valve open. It is determined whether or not the degree is Ov-ref or higher (step S22). If the current valve opening Ov-pre is smaller than the reference valve opening Ov-ref, the deterioration of the O-ring progresses, and it is considered inappropriate or impossible to compensate for the buffering action. Therefore, an alarm is immediately issued to notify the operator of the machine tool 100 that the seal member of the pneumatic cylinder 90, particularly the O-ring, needs to be replaced (step S32). Similar to the alert, this alarm is also displayed by turning on a lamp (not shown) attached to the control panel (not shown) of the machine tool 100 or displaying it on the display (not shown) of the control panel. It can occur acoustically.

The current valve opening Ov-pre of the buffer regulating valve (first and second proportional valves 26 and 32 in the first embodiment, proportional valve 208 in the second embodiment) is equal to or larger than the reference valve opening Ov-ref. In the case of (Yes in step S22), the throttle strength by the buffer regulating valve (the first and second proportional valves 26 and 32 in the first embodiment and the proportional valve 208 in the second embodiment) is strengthened (in the case of Yes). Step S24). This is because, for example, the valve opening Ov when the throttle setting unit 58 opens the buffer adjusting valve (the first and second proportional valves 26 and 32 in the first embodiment and the proportional valve 208 in the second embodiment). Is reduced by a predetermined ratio (for example, 5%) or a reduction from the current valve opening degree Ov-pre.

After adjusting the valve opening of the cushioning control valve (first and second proportional valves 26 and 32 in the first embodiment, proportional valve 208 in the second embodiment) in this way, the current shutter opening / closing time Toc -pre is measured (step S26), and the measured shutter opening / closing time Toc-pre is compared again with the reference operating time To-ref (step S28). As a result of valve opening adjustment of the shock absorber (first and second proportional valves 26 and 32 in the first embodiment, proportional valve 208 in the second embodiment), the current shutter opening / closing time Toc-pre is used as a reference. When the operation time To-ref (0.7 seconds in the example of FIG. 4) or more (Yes in step S28), the adjustment is completed (step S30).

Even after adjusting the valve opening of the shock absorber (first and second proportional valves 26 and 32 in the first embodiment, proportional valve 208 in the second embodiment), the shutter opening / closing time Toc-pre is the reference operation. Less than time To-ref (No in step S28), return to step S22, buffer regulating valve (first and second proportional valves 26, 32 in the first embodiment, proportional in the second embodiment) It is determined again whether or not the current valve opening degree Ov-pre of the valve 208) is equal to or greater than the reference valve opening degree Ov-ref. If the current valve opening Ov-pre is not equal to or greater than the reference valve opening Ov-ref (No in step S22), an alarm is issued in step S32. When the reference valve opening degree is Ov-ref or more (Yes in step S22), the buffer adjusting valve is further implemented in step S24 (in the first embodiment, the first and second proportional valves 26, 32, and the second implementation. In the embodiment, the valve opening degree Ov-pre when the proportional valve 208) is opened is set to be smaller, and in step S28, it is determined whether or not the shutter opening / closing time Toc-pre is equal to or longer than the reference operating time To-ref.

In this way, the buffer regulating valve (the first and second proportional valves 26 and 32 in the first embodiment and the proportional valve in the second embodiment) until the shutter opening / closing time Toc-pre becomes equal to or longer than the reference operating time To-ref. The adjustment of the valve opening degree Ov-pre in 208) is repeated. Meanwhile, the valve opening Ov-pre of the buffer regulating valve (the first and second proportional valves 26 and 32 in the first embodiment and the proportional valve 208 in the second embodiment) is from the reference valve opening Ov-ref. When it becomes smaller, an alarm is issued to notify the operator of the machine tool 100 that the O-ring of the piston of the pneumatic cylinder 90 should be replaced immediately.

10,200 Shutter switchgear 12 Pneumatic source 16,202 Directional control valve 22 First switching valve 24 First speed controller 26 First proportional valve 28 Second switching valve 30 Second speed controller 32 Second Proportional valve 50, 70 Controller 52, 72 Timer 54, 74 Buffer control unit 56, 76 Switchgear control unit 58, 78 Squeeze setting unit 60, 80 Storage unit 62, 82 Input unit 90 Pneumatic cylinder 138 Shutter 206 Squeeze 208 Proportional valve

In order to achieve the above object, according to the present invention, in the door opening / closing device of a machine tool that drives a door with a fluid pressure cylinder, the supply direction of the working fluid supplied from the fluid pressure source to the fluid pressure cylinder is controlled. A door open / close control valve for opening or closing the door, and a predetermined throttle provided in the fluid supply circuit or discharge circuit of the fluid pressure cylinder to regulate the speed of the door opening or closing operation. A high-strength speed control valve assembly, a buffer control valve provided in parallel with the speed control valve assembly and having a higher throttle strength than the speed control valve assembly, and the speed control valve assembly. , The buffer actuating valve that switches the flow of working fluid between the buffer adjusting valve and the door opening / closing control valve so that the door opens or closes, and the door opens or closes. At the start, the working fluid flows through the speed control valve assembly, and after a preset buffering operation start time elapses from the start of the opening or closing operation of the door, the fluid flows through the buffering control valve. , The buffer actuating valve is controlled , the time required for the opening operation in which the door moves from the closed position to the open position and / or the time required for the closing operation in which the door moves from the open position to the closed position is measured, and the measured time is measured. Provided is a door opening / closing device for a machine tool provided with a control device for shortening the buffering operation start time when the time is shorter than the reference time .

Claims (6)

In the door opening / closing device of a machine tool that drives a door with a fluid pressure cylinder
A door open / close control valve that controls the supply direction of the working fluid supplied from the fluid pressure source to the fluid pressure cylinder to open or close the door.
A speed control valve assembly provided in the fluid supply circuit or discharge circuit of the fluid pressure cylinder and having a predetermined throttle strength that regulates the speed of the opening operation or the closing operation of the door.
A cushioning control valve provided in parallel with the speed control valve assembly and having a higher throttle strength than the speed control valve assembly.
A buffering actuating valve that switches the flow of working fluid between the speed control valve assembly and the buffering regulating valve.
The door open / close control valve is controlled so that the door opens or closes, and at the start of the door opening or closing operation, the working fluid flows through the speed control valve assembly to open the door. A control device that controls the buffer operating valve so that the fluid flows through the buffer adjusting valve after a preset buffering operation start time elapses from the start of the operation or closing operation.
A door opening / closing device for machine tools characterized by being equipped with. The door opening / closing device has a fluid pressure source, a first pipeline connected to a head-side pressure chamber of the fluid pressure cylinder, the fluid pressure source, and a rod-side pressure chamber of the fluid pressure cylinder. It is equipped with a second pipeline connected to it.
The speed control valve assembly has first and second speed controllers arranged in the first and second pipelines.
The buffer regulating valve has first and second proportional valves disposed in the first and second pipelines.
The door opening / closing device according to claim 1, wherein the buffer actuating valve has first and second switching valves arranged in the first and second pipelines. Each of the first and second speed controllers is arranged in parallel with a check valve that allows the flow of working fluid from the door open / close control valve to the fluid pressure cylinder and a check valve. The door opening / closing device according to claim 2, further comprising a throttle valve. The control device measures the time required for the opening operation in which the door moves from the closed position to the open position and / or the time required for the closing operation in which the door moves from the open position to the closed position, and the measured time is longer than the reference time. The door opening / closing device according to claim 1, wherein when the buffering operation start time is short, the buffering operation start time is shortened by a predetermined time. When the buffer operation start time becomes shorter than the reference buffer operation start time, an alert is generated as a precaution for preventive maintenance of the replacement of the seal member of the fluid pressure cylinder, and the valve opening of the buffer adjusting valve is adjusted. The door opening / closing device according to claim 4. The door opening / closing device according to claim 5, wherein when the valve opening degree of the buffer adjusting valve becomes smaller than the reference valve opening degree, an alarm is issued to notify that the seal member of the fluid pressure cylinder needs to be replaced.

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