阅读说明：本技术 载物台装置及载物台控制装置 (Stage device and stage control device ) 是由 吉田达矢 滨田慎哉 近藤章 渡边真理乃 于 2021-03-22 设计创作，主要内容包括：本发明提出一种利用气动致动器使工件移动的载物台装置专用的安全停止机构,并提供具备这种安全停止机构的载物台装置。本发明的载物台装置具备：引导件；滑块；正侧伺服阀,将流体供给至腔室(152)或从该腔室内排出流体来控制该腔室内的压力；及负侧伺服阀,将流体供给至腔室(154)或从该腔室内排出流体来控制该腔室内的压力,一组截止阀(170P、170N)分别设置于将流体供给至腔室(152)的供给流路上及将流体供给至腔室(154)的供给流路上、或分别设置于从腔室(152)排出流体的排出流路上及从腔室(154)排出流体的排出流路上,截止阀(170P)与正侧伺服阀串联连接,截止阀(170N)与负侧伺服阀串联连接。(The invention provides a safety stop mechanism for a stage device for moving a workpiece by a pneumatic actuator, and provides a stage device having the safety stop mechanism. The stage device of the present invention includes: a guide; a slider; a positive side servo valve that controls pressure in a chamber (152) by supplying fluid to the chamber or discharging fluid from the chamber; and a negative servo valve for controlling the pressure in the chamber by supplying or discharging fluid to or from the chamber (154), wherein a set of shut-off valves (170P, 170N) are provided on a supply passage for supplying fluid to the chamber (152) and a supply passage for supplying fluid to the chamber (154), or on a discharge passage for discharging fluid from the chamber (152) and a discharge passage for discharging fluid from the chamber (154), respectively, the shut-off valves (170P) are connected in series to the positive servo valve, and the shut-off valves (170N) are connected in series to the negative servo valve.)

1. A stage device is characterized by comprising:

a guide;

a slider that moves along the guide by a pressure change in two chambers provided inside thereof;

a1 st pressure control valve that controls a pressure in one of the two chambers by supplying or discharging a fluid into or from the one chamber; and

a2 nd pressure control valve that controls a pressure in the other chamber by supplying or discharging fluid into or from the other chamber,

a set of shut-off valves is provided on a supply flow path for supplying a fluid to the one chamber and a supply flow path for supplying a fluid to the other chamber, or on a discharge flow path for discharging a fluid from the one chamber and a discharge flow path for discharging a fluid from the other chamber, respectively, one shut-off valve of the set of shut-off valves is connected in series with the 1 st pressure control valve, and the other shut-off valve is connected in series with the 2 nd pressure control valve.

2. The stage apparatus of claim 1,

the set of stop valves operate simultaneously.

3. The stage apparatus according to claim 1 or 2,

the group of stop valves comprises a1 st stop valve arranged between the 1 st pressure control valve and one chamber and a2 nd stop valve arranged between the 2 nd pressure control valve and the other chamber.

4. The stage apparatus according to claim 1 or 2,

the set of stop valves includes a1 st stop valve provided in a1 st fluid supply pipe that supplies the 1 st pressure control valve with fluid, and a2 nd stop valve provided in a2 nd fluid supply pipe that supplies the 2 nd pressure control valve with fluid.

5. The stage apparatus according to claim 1 or 2,

the set of the shutoff valves includes a1 st shutoff valve disposed in a fluid discharge pipe discharging the fluid from the 1 st pressure control valve and a2 nd shutoff valve disposed in a fluid discharge pipe discharging the fluid from the 2 nd pressure control valve.

6. The stage apparatus according to any one of claims 1 to 5,

further provided with:

an abnormality detection unit that detects an abnormality when the slider moves; and

and a valve control unit that closes the group of shutoff valves when the abnormality detection unit detects an abnormality.

7. The stage apparatus according to claim 1 or 2,

the one set of shutoff valves is provided on a supply passage through which the fluid is supplied to the one chamber and a supply passage through which the fluid is supplied to the other chamber, and the other set of shutoff valves is provided on a discharge passage through which the fluid is discharged from the one chamber and a discharge passage through which the fluid is discharged from the other chamber, respectively.

8. A stage device is characterized by comprising:

a guide;

a slider that moves along the guide by a pressure change in two chambers provided inside thereof;

a1 st pressure control valve that controls a pressure in one of the two chambers by supplying or discharging a fluid into or from the one chamber; and

a2 nd pressure control valve that controls a pressure in the other chamber by supplying or discharging fluid into or from the other chamber,

a group of exhaust valves is provided in a supply flow path for supplying fluid to the one chamber and a supply flow path for supplying fluid to the other chamber, respectively, one exhaust valve of the group of exhaust valves is connected in series with the 1 st pressure control valve, and the other exhaust valve is connected in series with the 2 nd pressure control valve.

9. A stage device is characterized by comprising:

a guide;

a slider moving along the guide by a pressure change inside thereof;

a pressure control valve provided on a supply flow path or a discharge flow path of a fluid for changing a pressure in the slider; and

and a shutoff valve or an exhaust valve provided on the supply flow path or the exhaust flow path.

10. A stage control device is characterized by comprising:

an abnormality detection unit that detects an abnormality when the slider that moves based on a change in internal pressure moves; and

and a valve control unit that closes a shut-off valve provided in a supply flow path or a discharge flow path of a fluid for changing a pressure in the slider or opens an exhaust valve provided in the supply flow path or the discharge flow path when the abnormality is detected by the abnormality detection unit.

Technical Field

The present invention relates to a stage device and a stage control device.

Background

Conventionally, various techniques have been proposed as a safety stop mechanism for a machine driven by a pneumatic actuator (for example, patent document 1).

Patent document 1: japanese laid-open patent publication No. 10-159813

Disclosure of Invention

The invention aims to provide a safety stop mechanism special for a stage device for moving a workpiece by using a pneumatic actuator, and provides the stage device with the safety stop mechanism.

In order to solve the above problem, one embodiment of the present invention includes: a guide; a slider that moves along the guide by a pressure change in two chambers provided inside thereof; a1 st pressure control valve for controlling a pressure in one chamber by supplying or discharging a fluid into or from one of the two chambers; and a2 nd pressure control valve for controlling the pressure in the other chamber by supplying or discharging fluid to or from the other chamber, wherein a set of shutoff valves is provided on a supply passage for supplying fluid to the one chamber and a supply passage for supplying fluid to the other chamber, or on a discharge passage for discharging fluid from the one chamber and a discharge passage for discharging fluid from the other chamber, respectively, one of the shutoff valves is connected in series with the 1 st pressure control valve, and the other shutoff valve is connected in series with the 2 nd pressure control valve.

According to the present invention, a stage device provided with a safety mechanism can be provided.

Drawings

Fig. 1 is a perspective view of the stage device.

Fig. 2 is a schematic cross-sectional view of the pneumatic actuator.

Fig. 3 is a cross-sectional view of the servo valve.

Fig. 4 is a graph showing temporal changes in the speed of the slider, the acceleration of the slider, and the pressure value in the servo chamber during normal operation.

Fig. 5 is a simplified configuration diagram of the stage device.

Fig. 6 is a graph showing temporal changes in the speed of the slider, the acceleration of the slider, and the pressure value in the servo chamber when abnormality occurs in the stage device of fig. 5.

Fig. 7 is a simplified configuration diagram of the stage device.

Fig. 8 is a graph showing temporal changes in the speed of the slider, the acceleration of the slider, and the pressure value in the servo chamber when abnormality occurs in the stage device of fig. 7.

Fig. 9 is a simplified configuration diagram of the stage device.

Fig. 10 is a graph showing temporal changes in the speed of the slider, the acceleration of the slider, and the pressure value in the servo chamber when an abnormality occurs in the stage device shown in fig. 9.

Fig. 11 is a simplified configuration diagram of the stage device.

Fig. 12 is a graph showing temporal changes in the speed of the slider, the acceleration of the slider, and the pressure value in the servo chamber when abnormality occurs in the stage device of fig. 11.

Fig. 13 is a simplified configuration diagram of the stage device.

In the figure: 100-stage device, 110-stage, 122-guide, 124-slide, 126-servo valve, 144P-positive side air supply, 144N-negative side air supply, 150-servo chamber, 152-positive side chamber, 154-negative side chamber, 170P, 170N, 180P, 180N, 190P, 190N-stop valve, 200P, 200N-exhaust valve.

Detailed Description

In the following drawings, the same or equivalent constituent elements, components, and steps are denoted by the same reference numerals, and overlapping description thereof will be omitted as appropriate. In the drawings, the dimensions of components are shown enlarged or reduced as appropriate for ease of understanding. In the drawings, parts that are not essential to the description of the embodiments are omitted.

Fig. 1 is a perspective view of the stage device. The stage device 100 mainly includes: platform 102, vibration isolation table 104, vibration isolation device 106, table 110, 1X-axis pneumatic actuator 120 extending in the X-axis direction, and two Y-axis pneumatic actuators 130A, 130B extending in the Y-axis direction. The platform 102 is supported by a vibration canceling platform 104. The X-axis pneumatic actuator 120 and the Y-axis pneumatic actuators 130A and 130B are H-shaped in plan view. The vibration damper 106 absorbs the force caused by the movement of the X-axis pneumatic actuator 120 and the Y-axis pneumatic actuators 130A, 130B, thereby suppressing the vibration of the stage 102.

The X-axis pneumatic actuator 120 has a guide (square shaft) 122, a slider 124, and a servo valve (not shown in fig. 1). The Y-axis pneumatic actuators 130A, 130B have a guide 132, a slider 134, and a servo valve 136, respectively. Both ends of the guide 122 are supported by a slider of the Y-axis pneumatic actuator 130A and a slider 134 of the Y-axis pneumatic actuator 130B, respectively. The slider 124 moves in the X-axis direction along the guide 122. The X-axis pneumatic actuator 120 moves in the Y-axis direction along the Y-axis pneumatic actuators 130A, 130B in accordance with the movement of the slider 134. Thus, the stage device 100 moves the table 110 and the slider 124 together in the XY plane. The table 110, the X-axis pneumatic actuator 120, and the Y-axis pneumatic actuators 130A, 130B are enclosed by the housing 108 and placed in a vacuum environment.

The position sensor 140 detects the position of the table 110 in the X-axis direction. The position sensor 142 detects the position of the table 110 in the Y-axis direction.

Fig. 2 is a schematic cross-sectional view of the pneumatic actuator. Specifically, fig. 2 schematically shows a vertical cross section at the center of the guide 122 in the Y-axis direction.

The guide 122 is provided with a hydrostatic bearing, and the slider 124 is suspended with respect to the guide 122 by an air bearing provided on each of the inner circumferential surfaces thereof. Thereby, the slider 124 is supported so as to be movable in the X-axis direction without contacting the guide 122 at all. Although not shown, the table 110 (see fig. 1) is fixed to a surface of the slider 124 on the positive side in the Z-axis direction, and moves in the X-axis direction together with the slider 124.

An inner space (i.e., a servo chamber 150) is provided on the slider 124, and the servo chamber 150 is divided into a positive side chamber 152 and a negative side chamber 154 by a pressure receiving plate 123 fixed to the guide member 122.

The X-axis pneumatic actuator 120 includes a positive servo valve 126P (corresponding to the 1 st pressure control valve in this example) and a negative servo valve 126N (corresponding to the 2 nd pressure control valve in this example) that are respectively disposed on the positive side and the negative side in the X-axis direction. The slider 124 is driven by a positive side servo valve 126P and a negative side servo valve 126N. The positive servo valve 126P and the negative servo valve 126N control the amount of air supplied to and exhausted from the positive chamber 152 and the negative chamber 154 in accordance with the position of a spool, which will be described later. The positive side servo valve 126P communicates with the positive side chamber 152 via the positive side pipe 128P. The negative servo valve 126N communicates with the negative chamber 154 via a negative pipe 128N.

The X-axis pneumatic actuator 120 generates a pressure difference between the positive side chamber 152 and the negative side chamber 154 by controlling the positive side servo valve 126P and the negative side servo valve 126N. The velocity and acceleration of the slider 124 with respect to the guide 122 are controlled by the pressure difference.

The positive servo valve 126P and the negative servo valve 126N are connected to an air supply source (i.e., a pump 146) via a positive air supply pipe 144P (corresponding to the 1 st fluid supply pipe in this example) and a negative air supply pipe 144N (corresponding to the 2 nd fluid supply pipe in this example), respectively. Positive servo valve 126P and negative servo valve 126N are configured to be able to discharge air to the outside of casing 108 (see fig. 1) through a positive air discharge pipe 148P (corresponding to the 1 st fluid discharge pipe in this example) and a negative air discharge pipe 148N (corresponding to the 2 nd fluid discharge pipe in this example), respectively. Air from the pump 146 is supplied to the positive side chamber 152 through the positive side air supply pipe 144P, the positive side servo valve 126P, and the positive side pipe 128P. Therefore, the positive side air supply pipe 144P, the positive side servo valve 126P, and the positive side pipe 128P constitute a positive side air supply flow path. The air from the pump 146 is supplied to the negative chamber 154 through the negative air supply pipe 144N, the negative servo valve 126N, and the negative pipe 128N. Therefore, the negative air supply pipe 144N, the negative servo valve 126N, and the negative pipe 128N constitute a negative air supply flow path. The air in the positive side chamber 152 is discharged to the outside through the positive side pipe 128P, the positive side servo valve 126P, and the positive side air discharge pipe 148P. Therefore, the positive side pipe 128P, the positive side servo valve 126P, and the positive side air discharge pipe 148P constitute a positive side air discharge flow path. The air in the negative chamber 154 is discharged to the outside through the negative pipe 128N, the negative servo valve 126N, and the negative air discharge pipe 148N. Therefore, the negative-side pipe 128N, the negative-side servo valve 126N, and the negative-side air outlet pipe 148N constitute a negative-side air outlet flow path.

The stage device 100 includes a controller 200 that controls the positive servo valve 126P and the negative servo valve 126N.

Fig. 3 is a cross-sectional view of the servo valve. The configuration of the positive servo valve 126P is the same as that of the negative servo valve 126N, and therefore, the following description will be given in detail collectively as "servo valve 126". In addition, the terms of "positive side" and "negative side" and the symbols "N" and "P" are also omitted for the components relating to the structure of the servo valve 126.

As shown in fig. 3, the servo valve 126 includes a main body 160, a spool 162 disposed in the main body 160, a motor 164, and a position sensor 166. The servo valve 126 is a three-way valve having three ports 168A, 168B, 168C. The servo valve 126 switches the connection destination of one 168C of the three ports between the ports 168A or 168B by the position of the spool 162. The spool 162 is disposed in a flow path extending in the Z-axis direction inside the main body 160, and is movable in the Z-axis direction. The position of the spool 162 is changed by the driving amount of the motor 164. The position sensor 166 detects the position of the spool 162. Two ports 168A and 168B aligned in the Z-axis direction are provided on one side surface of the main body 160, the port 168A located on the positive side in the Z-axis direction is connected to the air outlet pipe 148, and the port 168B located on the negative side in the Z-axis direction is connected to the air supply pipe 144. It is also possible to connect port 168A to air supply line 144 and port 168B to air exhaust line 148. The port 168C located on the other side surface of the main body 160 is connected to the pipe 128. The detection result of the position sensor 166 is supplied to the amplifier unit AU of the controller 200. The controller 200 acquires the position of the spool 162 based on the detection result acquired by the amplifier unit AU, and controls the motor 164 based on the acquired position. The controller 200 drives the motor 164 to control the position of the spool 162, so that air supplied from the pump 146 (see fig. 2) is supplied to the servo chamber 150 through the servo valve 126, or air in the servo chamber 150 is discharged through the servo valve 126. In fig. 3, the servo valve 126 is arranged such that the spool 162 moves in the Z-axis direction, but the orientation of the servo valve 126 is not limited to this direction.

Next, the operation of the stage device 100 during normal operation will be described. Fig. 4 shows temporal changes in the velocity v of the slider 124, the acceleration α of the slider 124, and the pressure P in the servo chamber 150 during normal operation.

Referring to fig. 2 to 4, when moving the slider 124 toward the positive side, the controller 200 moves the spool 162 of the positive side servo valve 126P so as to close the port 168A connected to the positive side air outlet pipe 148P and open the port 168B connected to the positive side air supply pipe 144P. At the same time, the controller 200 moves the spool 162 of the negative servo valve 126N to open the port 168A connected to the negative air outlet tube 148N and close the port 168B connected to the negative air supply tube 144N. Thus, air is supplied into the positive side chamber 152 so that the pressure P1 rises, and air is discharged from the negative side chamber 154 so that the pressure P2 falls (time t 0). When a pressure difference is generated between the pressure P1 and the pressure P2, the acceleration α increases, and the slider 124 is accelerated (time t0 to time t 1). The controller 200 controls the positive servo valve 126P and the negative servo valve 126N such that the differential pressure between the pressure P1 and the pressure P2 becomes zero when the speed v of the slider 124 reaches a predetermined speed v1 (time t1 to t 2). If the pressure difference becomes zero, the slider 124 moves at a constant speed.

Next, the controller 200 decelerates the slider 124 so that the velocity v becomes zero when the slider 124 reaches the target position. In this case, the controller 200 moves the spool 162 of the positive side servo valve 126P so as to open the port 168A connected to the positive side air outlet pipe 148P and close the port 168B connected to the positive side air supply pipe 144P. At the same time, the controller 200 moves the spool 162 of the negative servo valve 126N to close the port 168A connected to the negative air outlet tube 148N and open the port 168B connected to the negative air supply tube 144N. Thus, air is discharged from the positive side chamber 152 so that the pressure P1 falls, and air is supplied to the negative side chamber 154 so that the pressure P2 rises. When a pressure difference is generated between the pressure P1 and the pressure P2, the acceleration α decreases, and the slider 124 is decelerated (time t 2). The controller 200 causes the pressure difference to become zero when the slider 124 reaches the target position, thereby stopping the slider 124 (time t 3).

Next, the characteristic parts of the stage device 100 will be described.

Returning to fig. 2, the stage device 100 includes a shutoff valve or an exhaust valve that blocks the flow of air at least at any one of the positions a1, a position a2, a position B1, a position B2, a position C1, and a position C2 shown in the figure. Here, blocking the air flow means: the air flow during normal operation of the stage apparatus 100 is blocked, thereby reducing the pressure differential between the positive side chamber 152 and the negative side chamber 154. More specifically, blocking air means: the supply of air toward the servo chamber 150 that generates pressure for driving the slider 124 or the discharge of air from the servo chamber 150 is blocked. As concrete methods for blocking the air, a method of closing the supply path, a method of blocking the exhaust path to reduce the pressure variation in the servo chamber 150, and a method of opening the supply path to prevent the air from reaching the servo chamber 150 are included.

Fig. 5 is a simplified configuration diagram of the stage device. More specifically, fig. 5 is a diagram in which a shutoff valve is provided at both position a1 and position a2 shown in fig. 2. The stage device 100 includes a stop valve 170P (corresponding to the 1 st stop valve in this example) at an arbitrary position in the positive side pipe 128P extending between the positive side servo valve 126P and the servo chamber 150. The stage device 100 further includes a stop valve 170N (corresponding to the 2 nd stop valve in this example) at an arbitrary position in the negative side pipe 128N extending between the negative side servo valve 126N and the servo chamber 150. The cutoff valve 170P is connected in series with the positive side servo valve 126P, and the cutoff valve 170N is connected in series with the negative side servo valve 126N. The shutoff valves 170P and 170N are provided in the pipe 128 through which air flows bidirectionally, and therefore may be referred to as bidirectional shutoff valves. The shutoff valves 170P, 170N are controlled by the controller 200. The controller 200 includes an abnormality detection unit 200A and a valve control unit 200B. The abnormality detection unit 200A detects an abnormality related to the movement of the slider 124. The valve control unit 200B maintains the open state of the shutoff valves 170P and 170N during normal operation, and closes the shutoff valves 170P and 170N simultaneously when an abnormality occurs.

"abnormal" means: some anomalies in the movement mechanism associated with the movement of the slider 124. The moving mechanism of the slider 124 includes a positive servo valve 126P, a negative servo valve 126N, the slider 124 itself, sensors for detecting various parameters of the slider 124, and a communication device for communicating detected values. The slider 124 moves together with the table 110, and thus a component related to driving of the slider 124 is also a moving mechanism of the table 110.

Examples of anomalies are: failure of the positive side servo valve 126P and the negative side servo valve 126N, mechanical failure of the slider 124 itself, and failure of the control system of the slider 124. The controller 200 also determines that an abnormality has occurred when the user performs an operation such as pressing an emergency stop button.

For example, the spool 162 (refer to fig. 3) of the servo valve 126 may be unable to move due to a failure of the motor 164 or due to inclusion of some foreign matter. In this case, the drive current supplied to the motor 164 does not match the change in the position of the spool 162 detected by the position sensor 166.

For example, if a mechanical failure occurs in the slider 124, the feedback value of the movement speed, acceleration, or position of the slider 124 deviates from the control command value. When the speed sensors or the position sensors 140 and 142 provided on the slider 124 fail or the communication mechanism that transmits the detection values of the sensors to the controller 200 fails, the feedback values may deviate from the control values or the feedback values may not be obtained. The position of the slider 124 cannot be acquired even when an encoder for reading the position of the slider 124 malfunctions.

For example, if the slider 124 or a component related to the driving of the slider 124 experiences a mechanical failure, the slider 124 may move at a speed faster than the speed expected by the design. Also, although the slider 124 actually moves at a low speed, the detection value of the speed sensor becomes faster than the intended speed in design due to a failure of the speed sensor.

When an abnormality occurs while moving the table 110 and the slider 124, the controller 200 executes the following control.

Next, a case where an abnormality occurs in which the speed of the slider 124 exceeds a threshold value when the slider 124 is moved to the front side in the stage device 100 shown in fig. 5 will be described. Fig. 6 shows changes with time in the velocity v of the slider 124, the acceleration α of the slider 124, and the pressure P in the servo chamber 150.

Referring to fig. 5 and 6, during the period when the slider 124 is moved toward the positive side (time t10 to time t11), air is supplied to the positive side chamber 152 through the positive side servo valve 126P, and air is discharged from the negative side chamber 154 through the negative side servo valve 126N. Thus, the pressure difference between the pressure P1 (indicated by a solid line in fig. 6) of the positive side chamber 152 and the pressure P2 (indicated by a broken line in fig. 6) of the negative side chamber 154 is kept constant. When an abnormality occurs in which the speed v of the slider 124 exceeds the threshold value vt at time t11, the controller 200 detects the abnormality and closes the shutoff valves 170P and 170N at the same time. When the shutoff valves 170P and 170N are closed, the supply of air to the positive side chamber 152 and the discharge of air from the negative side chamber 154 are stopped. Thus, the amount of air in the positive side chamber 152 and the positive side pipe 128P is kept constant. In addition, the amount of air in the negative chamber 154 and the negative pipe 128N is also kept constant.

Even if the shutoff valves 170P, 170N are closed, the pressure P1 is not balanced with the pressure P2, and therefore the slider 124 continues to move toward the positive side. Therefore, the volume of the positive side chamber 152 continues to increase, and the pressure P1 of the positive side chamber 152 decreases. At the same time, the volume of the negative side chamber 154 continues to decrease, while the pressure P2 of the negative side chamber 154 increases. Therefore, the pressure difference between the pressure P1 and the pressure P2 becomes small, and the acceleration α of the slider 124 decreases.

At time t12, if the pressure P2 in the negative side chamber 154 becomes greater than the pressure P1 in the positive side chamber 152, the force pulling the slider 124 toward the negative side acts on the slider 124. At this time, the force acting on the slider 124 becomes a braking force of the slider 124 moving toward the positive side. Thereby, at time t12, the speed v of the slider 124 starts to decrease.

After time t12, the pressure difference between pressure P2 and pressure P1 continues to become greater, and the acceleration α approaches zero. Therefore, the braking force acting on the slider 124 gradually attenuates, and the acceleration α becomes zero when the differential pressure becomes zero at time t 13. In the illustrated example, the acceleration α of the slider 124 is increased only once after being decreased, but the acceleration α may be attenuated while being increased and decreased repeatedly a plurality of times.

By closing the shutoff valves 170P and 170N in this manner, the braking force can be applied to the slider 124 by the air in the positive side chamber 152 and the positive side pipe 128P and the air in the negative side chamber 154 and the negative side pipe 128N.

As described above, the controller 200 drives the slider 124 using the pressure difference between the positive side chamber 152 and the negative side chamber 154. With this driving method, even if the power supply to the stage device 100 is turned off when an abnormality occurs, the slider 124 does not immediately stop and continues to move due to the inertial force. Similarly, even if the supply of air to the stage device 100 is stopped, the slider 124 is not immediately stopped. The controller 200 closes the shutoff valves 170P and 170N to shut off the entrance and exit of air into and from the positive side chamber 152 and the negative side chamber 154, and causes the braking force to act on the slider 124 by a change in the differential pressure between the pressure P1 and the pressure P2. This can decelerate the slider 124 and the table 110, and can suppress high-speed collision with other components.

Next, a case where an abnormality occurs in which the speed of the slider 124 exceeds a threshold value when the slider 124 is moved to the front side in the stage device 100 shown in fig. 7 will be described. Fig. 7 is a simplified configuration diagram of the stage device. Fig. 8 shows changes with time in the velocity v of the slider 124, the acceleration α of the slider 124, and the pressure P in the servo chamber 150.

In this example, the stage device 100 includes a stop valve 180P (corresponding to the 1 st stop valve in this example) and a stop valve 180N (corresponding to the 2 nd stop valve in this example) at a position B1 and a position B2 shown in fig. 2, respectively. Specifically, shutoff valve 180P is disposed at an arbitrary position in positive air outlet pipe 148P. Stop valve 180N is disposed at an arbitrary position in negative air outlet pipe 148N connected to negative servo valve 126N. The cut-off valve 180P is connected in series with the positive side servo valve 126P, and the cut-off valve 180N is connected in series with the negative side servo valve 126N. The shutoff valves 180P and 180N are provided in the positive air outlet pipe 148P and the negative air outlet pipe 148N for discharging air, and therefore may be referred to as discharge pipe shutoff valves. The shutoff valves 180P, 180N are controlled by the controller 200. The controller 200 maintains the shutoff valves 180P and 180N in the open state during normal operation, and closes the shutoff valves 180P and 180N simultaneously when an abnormality occurs. In this example, the controller 200 functions as a stage control device including an abnormality detection unit and a valve control unit.

Referring to fig. 7 and 8, during the period when the slider 124 is moved toward the positive side (time t20 to time t21), air is supplied to the positive side chamber 152 through the positive side servo valve 126P, and air is discharged from the negative side chamber 154 through the negative side servo valve 126N. Thus, the pressure difference between the pressure P1 (indicated by a solid line in fig. 8) of the positive side chamber 152 and the pressure P2 (indicated by a broken line in fig. 8) of the negative side chamber 154 is kept constant. When an abnormality occurs in which the speed v of the slider 124 exceeds the threshold value vt at time t21, the controller 200 detects the abnormality and closes the shutoff valves 180P and 180N. When the shutoff valves 180P and 180N are closed, the exhaust from the positive chamber 152 and the negative chamber 154 is stopped. This prevents the amount of air in the positive side chamber 152 and in the positive side pipe 128P between the shutoff valve 180P and the positive side chamber 152 from decreasing. Further, the amount of air in the negative side chamber 154 and in the negative side pipe 128N between the shutoff valve 180N and the negative side chamber 154 is not reduced.

Even if the shutoff valves 180P, 180N are closed, the slider 124 continues to move toward the positive side due to the inertial force. Therefore, the volume of the positive side chamber 152 continues to increase, and the pressure P1 of the positive side chamber 152 decreases. At the same time, the volume of the negative side chamber 154 continues to decrease, and air does not escape from the negative side chamber 154, so the pressure P2 in the negative side chamber 154 increases. Thereby, the pressure difference between the pressure P1 in the positive side chamber 152 and the pressure P2 in the negative side chamber 154 becomes small, and the acceleration α of the slider 124 decreases.

At time t22, when the pressure P2 in the negative side chamber 154 becomes greater than the pressure P1 in the positive side chamber 152, the force that pulls the slider 124 toward the negative side acts on the slider 124, and therefore, a braking force acts on the slider 124. Thus, at time t22, the velocity v of the slider 124 begins to decrease.

After time t22, the pressure difference between pressure P2 and pressure P1 continues to become greater, and the acceleration α approaches zero. Therefore, the braking force acting on the slider 124 gradually attenuates, and the acceleration α becomes zero when the differential pressure becomes zero at time t 23.

By closing the shutoff valves 180P and 180N in this manner, the braking force can be applied to the slider 124 by the air in the positive side chamber 152 and the positive side pipe 128P and the air in the negative side chamber 154 and the negative side pipe 128N. This can suppress high-speed collision of the table 110 with another member. This example is particularly effective when at least one of the positive side servo valve 126P or the negative side servo valve 126N is in a state in which it is able to exhaust.

Next, in the stage device 100 shown in fig. 9, a case where an abnormality occurs in which the speed v of the slider 124 exceeds the threshold value vt when the slider 124 is moved to the positive side will be described. Fig. 9 is a simplified configuration diagram of the stage device. Fig. 10 shows changes with time in the velocity v of the slider 124, the acceleration α of the slider 124, and the pressure P in the servo chamber 150.

In this example, the stage device 100 includes a stop valve 190P (corresponding to the 1 st stop valve in this example) and a stop valve 190N (corresponding to the 2 nd stop valve in this example) at a position C1 and a position C2 shown in fig. 2, respectively. The shutoff valve 190P is disposed at an arbitrary position in the positive side air supply pipe 144P connected to the positive side servo valve 126P. The shutoff valve 190N is disposed at an arbitrary position in the negative air supply pipe 144N connected to the negative servo valve 126N. The shutoff valve 190P is connected in series with the positive side servo valve 126P, and the shutoff valve 190N is connected in series with the negative side servo valve 126N. The shutoff valves 190P and 190N are provided in the positive air supply pipe 144P and the negative air supply pipe 144N for supplying air, and therefore may be referred to as supply pipe shutoff valves. The shutoff valves 190P, 190N are controlled by a controller 200. The controller 200 maintains the shutoff valves 190P and 190N in an open state during normal operation, and closes the shutoff valves 190P and 190N simultaneously when an abnormality occurs. In this example, the controller 200 functions as a stage control device including an abnormality detection unit and a valve control unit.

Referring to fig. 9 and 10, during the period in which the slider 124 is moved toward the positive side (time t30 to time t31), air is supplied to the positive side chamber 152 through the positive side servo valve 126P, and air is discharged from the negative side chamber 154 through the negative side servo valve 126N. Thus, the pressure difference between the pressure P1 (indicated by a solid line in fig. 10) of the positive side chamber 152 and the pressure P2 (indicated by a broken line in fig. 10) of the negative side chamber 154 is kept constant. When an abnormality occurs in which the speed v of the slider 124 exceeds the threshold value vt, the controller 200 detects the abnormality and closes the shutoff valves 190P and 190N. When the controller 200 closes the shutoff valves 190P and 190N at time t31, the supply of air into the servo chamber 150, the positive side servo valve 126P, and the negative side servo valve 126N is blocked. This prevents an increase in the amount of air in the positive side chamber 152 and in the positive side pipe 128P between the shutoff valve 190P and the positive side chamber 152. At the same time, the amount of air in the negative side chamber 154 and in the negative side pipe 128N between the shutoff valve 190N and the negative side chamber 154 does not increase.

Even if the shutoff valves 190P, 190N are closed, the slider 124 continues to move toward the positive side due to the inertial force. Thus, the volume of the positive side chamber 152 continues to increase, while the volume of the negative side chamber 154 continues to decrease. Since the volume in the positive side chamber 152 increases and air is not supplied from the positive side air supply pipe 144P, the pressure in the positive side chamber 152 decreases. Thereby, the pressure difference between the pressure P1 in the positive side chamber 152 and the pressure P2 in the negative side chamber 154 becomes gradually smaller. When the shutoff valves 190P, 190N are not provided, the pressure in the positive side chamber 152 is substantially smooth and does not change (reference line PN), and therefore the pressure of the slider 124 is also substantially smooth and does not change (reference line α N). In contrast, when the shutoff valves 190P and 190N are provided, the pressure in the positive side chamber 152 decreases compared to when the shutoff valves 190P and 190N are not provided. Therefore, the acceleration α is also lowered as compared with the case where the shutoff valves 190P and 190N are not provided. Therefore, when the pressures of the positive side chamber 152 and the negative side chamber 154 start to decrease simultaneously at time t31, the differential pressure between the positive side chamber 152 and the negative side chamber 154 gradually decreases, and the differential pressure becomes zero at time t 32. Thereby, the acceleration α of the slider 124 becomes zero, and the velocity v of the slider 124 becomes a constant velocity. Therefore, acceleration of the slider 124 can be suppressed, and high-speed collision of the table 110 with other components can be suppressed.

As described above, the table 110 can be decelerated or at least accelerated by providing the shutoff valves 170P, 170N, 180P, 180N, 190P, and 190N in the air flow path and blocking the flow of air when an abnormality occurs. This can improve the safety of the stage device 100. In particular, in a device that drives the slider 124 by supplying and discharging air, such as the stage device 100, even if power supply or air supply to the device is stopped, the device is not stopped. Therefore, it is particularly advantageous to provide the stop valves 170P, 170N, 180P, 180N, 190P, and 190N in the stage device 100 so that the braking force acts on the slider 124.

The stage device 100 simultaneously blocks the flow paths by the positive-side shutoff valves 170P, 180P, and 190P and the negative-side shutoff valves 170N, 180N, and 190N. This makes it possible to shift the pressures P1, P2 of the positive side chamber 152 and the negative side chamber 154 to an equilibrium state. For example, in the example shown in fig. 6, it is assumed that the closing timings of the shutoff valves 170P and 170N are shifted so that the positive-side shutoff valve 170P is closed after a lapse of time from the closing of the negative-side shutoff valve 170N. At this time, the timing at which the differential pressure between the positive side chamber 152 and the negative side chamber 154 becomes small is delayed or the amount of decrease in the differential pressure becomes small. Therefore, the timing at which the braking force acts on the slider 124 may be delayed or the braking force may be reduced. On the other hand, when the shutoff valves 170P and 170N are closed at the same time, the action timing of the braking force is advanced and the braking force increases. Here, "simultaneously" means: not all differences in time are meant, and some differences in time are also considered "simultaneous".

In addition to the shutoff valves 170P, 170N, 180P, 180N, 190P, and 190N, an exhaust valve and an exhaust passage may be provided at positions a1 and a2 or positions C1 and C2 on the supply passage to block the flow of air supplied to the positive chamber 152 and the negative chamber 154, or an exhaust valve and an exhaust passage may be provided at positions a1 and a2 or positions C1 and C2 on the supply passage to block the flow of air supplied to the positive chamber 152 and the negative chamber 154, instead of the shutoff valves 170P, 170N, 180P, 180N, 190P, and 190N.

Fig. 11 is a simplified configuration diagram of the stage device. As shown in fig. 11, the stage device 100 includes exhaust valves 200P and 200N in the positive side pipe 128P and the negative side pipe 128N, respectively. The exhaust valve 200P is disposed in series with the positive servo valve 126P, and the exhaust valve 200N is disposed in series with the negative servo valve 126N. The air discharged from the discharge valves 200P, 200N is preferably discharged to the outside of the casing 108 (refer to fig. 1) through a discharge path. The exhaust valves 200P and 200N are controlled by a valve control unit 200B of the controller 200. When the abnormality detector 200A detects an abnormality and opens the exhaust valves 200P and 200N, the air in the positive chamber 152 is discharged to the outside through the exhaust valve 200P and the exhaust path. At the same time, the air in the negative chamber 154 is discharged to the outside through the exhaust valve 200N and the exhaust path.

Fig. 12 is a graph showing temporal changes in the speed of the slider, the acceleration of the slider, and the pressure value in the servo chamber when abnormality occurs in the stage device of fig. 11. While the slider 124 is moving toward the positive side (time t40 to t41), air is supplied to the positive side chamber 152 through the positive side servo valve 126P, and air is discharged from the negative side chamber 154 through the negative side servo valve 126N. Thus, the pressure difference between the pressure P1 (indicated by a solid line in fig. 12) of the positive side chamber 152 and the pressure P2 (indicated by a broken line in fig. 12) of the negative side chamber 154 is kept constant. If an abnormality occurs in which the speed v of the slider 124 exceeds the threshold value vt, the controller 200 detects the abnormality and opens the exhaust valves 200P and 200N. When the controller 200 opens the exhaust valves 200P and 200N at time t41, the air in the servo chamber 150 is exhausted from the exhaust valves 200P and 200N. Thereby, the pressure difference between the positive side chamber 152 and the negative side chamber 154 becomes zero, and the slider 124 can be prevented from being further accelerated. In this example, the air in the positive side chamber 152 and the negative side chamber 154 can be discharged regardless of the states of the positive side servo valve 126P and the negative side servo valve 126N. Therefore, this example is effective particularly when the positive servo valve 126P and the negative servo valve 126N have failed for some reason.

Fig. 13 is a simplified configuration diagram of the stage device. As shown in fig. 13, the stage device 100 includes exhaust valves 210P and 210N in the positive air supply pipe 144P and the negative air supply pipe 144N, respectively. The exhaust valves 210P, 210N preferably exhaust air to the exterior of the housing 108 (see fig. 1). The exhaust valves 200P and 200N are controlled by a valve control unit 200B of the controller 200. When the abnormality detector 200A detects an abnormality and opens the exhaust valves 210P and 210N, the air from the pump 146 is discharged from the exhaust valve 210P via the positive air supply pipe 144P, and the supply of air to the positive chamber 152 is blocked. At the same time, the air from the pump 146 is discharged from the exhaust valve 210N after passing through the negative air supply pipe 144N, and the supply of the air to the negative chamber 154 is blocked. Accordingly, the pressures in the positive side chamber 152 and the negative side chamber 154, the speed of the slider 124, and the acceleration of the slider 124 show changes as shown in fig. 12. This can prevent the slider 124 from being further accelerated.

The present invention is not limited to the above-described embodiments, and various configurations can be appropriately changed without departing from the scope of the present invention.

The shutoff valves 170P, 170N, 180P, 180N, 190P, 190N and the exhaust valves 200P, 200N, 210P, 210N may be provided in one stage device.