JP6925785B2 - Actuator system - Google Patents

Description

The present invention relates to an actuator system.

Conventionally, for example, as shown in Patent Document 1, as an actuator system used for a precision positioning device or the like, a system including a fluid pressure actuator that generates thrust by supplying a fluid is known. In this actuator system, fluid is supplied to the fluid pressure actuator via a servo valve.

Japanese Unexamined Patent Publication No. 2004-144196

In the actuator system described in Patent Document 1, for example, a flow rate of fluid consumed in the system of the system (hereinafter, also simply referred to as "flow rate of consumption") may occur, and as a result, the thrust obtained may decrease. be. Therefore, in order to supply a larger amount of fluid to the fluid pressure actuator in consideration of the consumption flow rate, a servo valve having a higher capacity and a larger size is required, which makes it difficult to miniaturize the system. Therefore, there is room for improvement in terms of suppressing a decrease in the thrust obtained while reducing the size.

Therefore, an object of the present invention is to provide an actuator system capable of suppressing a decrease in thrust obtained while reducing the size.

In order to solve the above problems, the actuator system according to the present invention is an actuator system including a fluid pressure actuator that generates a thrust by supplying a fluid, and is switched to control the amount of fluid supplied from the supply source. A first flow path that supplies fluid to the fluid pressure actuator, and a second flow path that is connected in parallel with the first flow path and supplements the supply amount of fluid supplied from the first flow path to the fluid pressure actuator. It has.

In the present invention, the supply amount of the fluid supplied from the first flow path to the fluid pressure actuator is supplemented by the second flow path. Therefore, for example, even when the fluid is consumed in the system of the system, it is possible to make up for the shortage of the consumed fluid without increasing the supply amount itself from the first flow path. As a result, it is possible to suppress a decrease in the obtained thrust without increasing the size of the switching portion in order to increase the supply amount from the first flow path. From the above, it is possible to suppress a decrease in the thrust obtained while reducing the size.

Further, in the actuator system according to the present invention, a third flow path for supplying a fluid to the fluid pressure actuator is further provided, the second flow path is branched from the third flow path, and the fluid pressure actuator is the first flow path. And may have a first supplied portion to which the fluid is supplied from the second flow path and a second supplied portion to which the fluid is supplied from the third flow path. In this case, the thrust of the fluid pressure actuator is generated according to the difference between the pressure in the first supplied portion and the pressure in the second supplied portion. A fluid is supplied to the second supplied portion from the third flow path. On the other hand, the fluid is supplied to the first supplied portion from the first flow path and the second flow path. Thereby, for example, even when the fluid is consumed in the system of the system, the consumed fluid is supplied by the supply of the fluid from the second flow path without increasing the supply amount itself from the first flow path. By compensating for the shortage, the amount of fluid that contributes to the pressure in the first supplied portion can be secured. As a result, it is possible to suppress a decrease in the obtained thrust without increasing the size of the switching portion in order to increase the supply amount from the first flow path. From the above, it is possible to suppress the decrease in thrust obtained while reducing the size.

Further, in the actuator system according to the present invention, the second flow path has an adjusting mechanism for adjusting the filling flow rate of the fluid supplementing the supply amount, and the adjusting mechanism is a supply source at least upstream of the switching portion in the first flow path. The replenishment flow rate may be adjusted so that the sum of the amount of fluid supplied from the system and the replenishment flow rate is larger than the flow rate of the fluid consumed in the system of the system. In this case, by adjusting the replenishment flow rate, the sum of the amount of fluid supplied from the supply source at least upstream of the switching portion in the first flow path and the replenishment flow rate is the sum of the fluid consumed in the system of the system. It is higher than the consumption flow rate. As a result, the amount of fluid that is insufficient to obtain the target thrust due to the fluid consumed in the system of the system is surely supplemented by the compensation flow rate, so that the target thrust can be surely obtained.

Further, the actuator system according to the present invention further includes a fourth flow path that is connected to the position of the switching portion in the first flow path or at least downstream of the switching portion and discharges the fluid in the first flow path to the low pressure side. The four flow paths may have a discharge adjusting mechanism for adjusting the discharge flow rate of the fluid. In this case, the amount of fluid supplied from the first flow path to the fluid pressure actuator is supplemented by the second flow path, while the fluid discharged from the first flow path to the low pressure side by the discharge adjustment mechanism of the fourth flow path. The discharge flow rate can be adjusted. As a result, the output characteristics of the actuator system can be easily adjusted.

According to the present invention, it is possible to provide an actuator system capable of suppressing a decrease in thrust obtained while reducing the size.

It is a schematic side view and the schematic sectional view which shows the actuator system which concerns on 1st Embodiment of this invention. It is a schematic block diagram of the actuator system which concerns on 1st Embodiment of this invention. It is a conceptual diagram which shows various diaphragm mechanisms. It is a figure which shows the flow of the fluid with respect to the control pressure chamber. It is a graph which shows the flow rate characteristic of a servo valve with respect to the pressure in a control pressure chamber. It is a schematic block diagram which shows the actuator system which concerns on 2nd Embodiment of this invention. It is a graph which shows the pressure characteristic of an actuator system.

Hereinafter, embodiments of the actuator system according to the present invention will be described with reference to the accompanying drawings. In the following description, the same or equivalent elements will be designated by the same reference numerals, and duplicate description will be omitted.

(First Embodiment)
The actuator system according to the present embodiment is a system that includes a fluid pressure actuator that uses a fluid and generates thrust by supplying a fluid to the fluid pressure actuator. The actuator system according to the present embodiment includes a cylinder using a fluid as a fluid pressure actuator, and is used, for example, for controlling the tension of a roll in a die bonder or a web transfer device used in a post-process of semiconductor manufacturing. The fluid may be, for example, compressed air or various other fluids.

FIG. 1 is a schematic side view and a schematic cross-sectional view showing an actuator system according to the first embodiment of the present invention. FIG. 1A shows a schematic side view of the actuator system, and FIG. 1B shows a schematic cross-sectional view taken along line II-II of FIG. 1A. FIG. 2 is a schematic configuration diagram of an actuator system according to the first embodiment of the present invention.

As shown in FIG. 1, the actuator system 1 includes a cylinder 10 (fluid pressure actuator), a servo valve 20 (switching portion), and a manifold block 30. The cylinder 10 has a substantially cylindrical shape, and is a drive mechanism that performs positioning control, load control, and the like. The servo valve 20 controls the supply amount of the fluid supplied to the cylinder 10 from the supply source of the fluid (compressed air in this embodiment).

The manifold block 30 is, for example, an integrally formed metal block. The manifold block 30 is arranged, for example, between the cylinder 10 and the servo valve 20. The manifold block 30 is formed with a plurality of pipelines, openings, and the like that form a flow path for supplying the fluid from the supply source to the cylinder 10. That is, the actuator system 1 includes a plurality of flow paths for supplying the fluid from the supply source to the cylinder 10. Hereinafter, the cylinder 10, the servo valve 20, and the flow path for supplying the fluid from the supply source to the cylinder 10 will be described in detail with reference to FIG.

As shown in FIG. 2, the cylinder 10 is integrally formed with a cylindrical housing 11, a piston 12 housed in the housing 11 so as to be movable back and forth, and a piston 12, and protrudes to the outside of the housing 11. The rod 13 and the rod 13 are provided. For example, a hydrostatic bearing (air bearing) (not shown) is formed in the gap between the inner peripheral surface 11a of the housing 11 and the piston 12 and the rod 13. By supplying the fluid from the supply unit 40 to the hydrostatic bearing, a fluid layer is formed in the gap between the inner peripheral surface 11a of the housing 11 and the piston 12 and the rod 13. As a result, the piston 12 is in a non-contact state with respect to the inner peripheral surface 11a of the housing 11.

The piston 12 has head portions 12a and 12b on both ends thereof, respectively. Inside the housing 11, a constant pressure chamber 10A (second supplied portion) partitioned by an end surface 12f of the head portion 12a of the piston 12 and an inner peripheral surface 11a of the housing 11 and an end surface 12e of the head portion 12b of the piston 12 A control pressure chamber 10B (first supplied portion) partitioned by an inner peripheral surface 11a of the housing 11 is formed. A rod 13 is introduced in the constant pressure chamber 10A. The piston 12 repeats forward movement and backward movement in a state of being non-contact with the inner peripheral surface 11a of the housing 11. Here, the traveling movement is a movement in the direction from the control pressure chamber 10B side to the constant pressure chamber 10A side (hereinafter, also simply referred to as “progressive movement”). The regressive movement is a movement in a direction from the constant pressure chamber 10A side to the control pressure chamber 10B side (hereinafter, also simply referred to as “regression movement”).

The fluid from the supply unit 40 (supply source) is supplied to the constant pressure chamber 10A at a constant pressure. The fluid from the supply unit 40 is supplied to the control pressure chamber 10B at a controlled controlled flow rate. The piston 12 is moved forward and backward according to the supply of the fluid to the constant pressure chamber 10A and the control pressure chamber 10B. That is, the thrust of the cylinder 10 is generated according to the difference between the pressure in the constant pressure chamber 10A and the pressure in the control pressure chamber 10B.

The servo valve 20 is provided in the control flow path 31 described later. The fluid from the supply unit 40 flows into the servo valve 20 through the regulator 41 in a state of being adjusted to a constant pressure. The servo valve 20 controls the amount of fluid supplied to the control pressure chamber 10B of the cylinder 10. The servo valve 20 controls the supply amount of this fluid with high accuracy and high response according to the electric signal input to the servo valve 20.

The servo valve 20 receives, for example, a signal indicating each pressure in the constant pressure chamber 10A and the control pressure chamber 10B detected by pressure sensors (not shown) provided in the constant pressure chamber 10A and the control pressure chamber 10B of the cylinder 10, respectively. Then, the amount of fluid supplied from the supply unit 40 is controlled so that the pressures in the constant pressure chamber 10A and the control pressure chamber 10B indicated by the signal are in an appropriate state. Here, the appropriate state is, for example, a state in which the thrust of the cylinder 10 output as the difference between the pressure in the constant pressure chamber 10A and the pressure in the control pressure chamber 10B becomes a desired magnitude. The servo valve 20 supplies a fluid amount based on, for example, a preset flow rate characteristic (for example, a control flow rate corresponding to the pressure in the control pressure chamber 10B required to generate a thrust of a desired magnitude). It may be controlled. The servo valve 20 supplies a fluid to the control pressure chamber 10B at a controlled control flow rate.

The servo valve 20 exhausts (exhausts) the fluid into the atmosphere, the supply port Ps to which the fluid is supplied from the supply unit 40, the control port Pc that supplies the fluid to the control pressure chamber 10B at the controlled control flow rate, and the fluid. It has an exhaust port Ex. The servo valve 20 is a three-way valve having fluid inlets and outlets in three directions of a supply port Ps, a control port Pc, and an exhaust port Ex.

As the servo valve 20, for example, a spool type or nozzle flapper type servo valve may be used. When, for example, a spool type servo valve is used as the servo valve 20, a large volume of fluid can flow. Further, when, for example, a nozzle flapper type servo valve is used as the servo valve 20, the responsiveness can be increased.

The actuator system 1 supplies a control flow path 31 (first flow path) that controls the fluid from the supply unit 40 by the servo valve 20 and supplies the fluid to the control pressure chamber 10B, and supplies the fluid from the supply unit 40 to the constant pressure chamber 10A. It includes a constant pressure flow path 33 (third flow path) and a compensation flow path 32 (second flow path) that supplements the supply amount of the fluid supplied to the control pressure chamber 10B by the control flow path 31. In the present embodiment, the upstream side and the downstream side in each flow path indicate the upstream side and the downstream side in the direction in which the fluid flows from the supply unit 40 side to the constant pressure chamber 10A side or the control pressure chamber 10B side.

One end of the control flow path 31 is connected to the supply unit 40, and the other end is connected to the control pressure chamber 10B. The control flow path 31 is provided with a regulator 41 and a servo valve 20. The control flow path 31 adjusts the fluid from the supply unit 40 to a constant pressure by the regulator 41. Then, the control flow path 31 controls the fluid adjusted to a constant pressure by the servo valve 20 and supplies the fluid to the control pressure chamber 10B at the control flow rate controlled by the servo valve 20.

One end of the constant pressure flow path 33 is connected to at least a position upstream of the servo valve 20 in the control flow path 31, and the other end is connected to the constant pressure chamber 10A. For example, the constant pressure flow path 33 is connected to the position between the regulator 41 and the servo valve 20 and the constant pressure chamber 10A. That is, the constant pressure flow path 33 branches from the position between the regulator 41 and the servo valve 20 of the control flow path 31. The constant pressure flow path 33 supplies the fluid adjusted to a constant pressure by the regulator 41 to the constant pressure chamber 10A in a constant pressure state without passing through the servo valve 20.

For example, one end of the compensation flow path 32 is connected to the constant pressure flow path 33, and the other end side is at least downstream of the servo valve 20 in the control flow path 31 (servo valve 20 and control pressure chamber 10B). It is connected to the position between). That is, the compensation flow path 32 is connected to the position between the regulator 41 and the servo valve 20 of the control flow path 31 via the constant pressure flow path 33, and is between the servo valve 20 and the control pressure chamber 10B. It joins the control flow path 31 at the position. In this way, the filling flow path 32 is connected in parallel with the control flow path 31. The filling flow path 32 is provided with a throttle mechanism (adjustment mechanism) 35.

The throttle mechanism 35 adjusts the compensation flow rate, which is the amount of fluid that supplements the supply amount of fluid from the control flow path 31. The compensation flow path 32 adjusts the flow rate of the fluid adjusted to a constant pressure by the regulator 41 to a predetermined compensation flow rate by reducing the flow rate by the throttle mechanism 35. The replenishment flow path 32 merges the fluid of the replenishment flow rate with the fluid from the servo valve 20 in the control flow path 31. As a result, the filling flow path 32 supplements the amount of fluid supplied from the control flow path 31.

The supplementary flow rate is the amount of fluid supplied from the control flow path 31 with respect to the flow rate of the fluid that needs to be supplied into the control pressure chamber 10B in order to obtain the target thrust of the cylinder 10 (hereinafter, also referred to as “required flow rate”). It is an amount to make up for the shortage. For example, the compensation flow rate is an amount that supplements the supply amount so as to reduce the difference obtained by subtracting the supply amount from the required flow rate. The shortage that the supply amount from the control flow path 31 is insufficient occurs, for example, due to the consumption of fluid in the system of the actuator system 1. The compensation flow rate supplements the supply amount of the fluid supplied from the control flow path 31 to the control pressure chamber 10B so that the thrust of the cylinder 10 does not decrease due to the shortage caused by the consumption of the fluid, for example. The quantity. Hereinafter, the consumption of the fluid in the system is also simply referred to as "consumption", and the flow rate of the fluid consumed in the system is also simply referred to as "consumption flow rate". The consumption flow rate is a fluid that does not contribute to the pressure in the control pressure chamber 10B, such as an amount that is consumed other than the supply into the control pressure chamber 10B or an amount that flows out of the control pressure chamber 10B. The amount.

Further, the compensation flow rate may be an amount that can surely obtain the target thrust as well as suppress the decrease in the thrust. For example, the compensation flow rate is an amount that supplements the supply amount so as to eliminate the difference obtained by subtracting the supply amount from the required flow rate, or to supply a fluid having a flow rate larger than the required flow rate into the control pressure chamber 10B. There may be.

The throttle mechanism 35 is a mechanism having resistance to cause a pressure loss in the flow of the fluid. The throttle mechanism 35 throttles the flow rate of the fluid and causes a pressure difference before and after the flow rate (upstream side and downstream side of the throttle mechanism 35 in the compensation flow path 32). The compensation flow rate adjusted by the drawing mechanism 35 may be a fixed amount or a variable amount. The compensation flow rate adjusted by the throttle mechanism 35 may be preset, and is a control device (not shown) so as to have a predetermined set value according to a state (for example, consumption flow rate, pressure, etc.) in the actuator system. It may be controlled by such as. The details of the adjustment range of the compensation flow rate will be described later.

FIG. 3 is a conceptual diagram showing various diaphragm mechanisms 35. For example, as shown in FIG. 3A, an orifice 36 may be formed in the middle of the filling flow path 32 as the throttle mechanism 35. The orifice 36 is, for example, a partition plate having a circular hole in the center. The filling flow rate is adjusted by the diameter of the hole in the center. Further, for example, as shown in FIG. 3B, the flow rate adjusting nozzle 37 may be formed in the middle of the filling flow path 32 as the throttle mechanism 35. Further, for example, as shown in FIG. 3C, the throttle valve 38 may be formed in the middle of the filling flow path 32 as the throttle mechanism 35. The throttle valve 38 has a threaded portion 39 having a tapered tip and a flow path portion 32a having a tapered tip along the tip of the threaded portion 39. The throttle valve 38 changes the flow rate of the fluid passing through the flow path portion 32a by moving the screw portion 39 up and down. As a result, the throttle valve 38 adjusts the compensation flow rate. The diameter α of the screw hole of the screw portion 39 is larger than the flow path diameter β on the upstream side of the flow path portion 32a.

Further, for example, as shown in FIG. 3D, the throttle valve 50 may be formed in the middle of the filling flow path 32 as the throttle mechanism 35. The throttle valve 50 has a substantially cylindrical micrometer 51 and a nozzle 52 provided at a position facing the tip 51a of the micrometer 51. The micrometer 51 can be driven in the direction of arrow X. The throttle valve 50 changes the distance between the tip 51a of the micrometer 51 and the nozzle 52 by driving the micrometer 51 in the direction of the arrow X, and changes the flow rate of the fluid passing through the distance. As a result, the throttle valve 50 adjusts the compensation flow rate. The micrometer 51 may be driven manually or automatically by being controlled by a control device (not shown) or the like. The throttle valve 50 may be preliminarily incorporated or retrofitted to the filling flow path 32. Further, the aperture mechanism 35 is not limited to these, and various other configurations may be adopted.

Next, the flow of the fluid in the entire actuator system 1 will be described with reference to FIGS. 1 and 2.

First, the flow of the fluid at the time of supply when the fluid is supplied to the control pressure chamber 10B will be described. In FIG. 2, solid arrows indicate the directions in which the fluid flows through the control flow path 31, the constant pressure flow path 33, and the compensation flow path 32 at the time of supply. At the time of supply, first, the fluid from the supply unit 40 flows through the control flow path 31, passes through the regulator 41, and is adjusted to a constant pressure. The fluid that has passed through the regulator 41 is divided into a flow that flows directly through the control flow path 31 and a flow that branches from the control flow path 31 to the constant pressure flow path 33 on the upstream side of the servo valve 20.

The fluid flowing through the control flow path 31 on the upstream side of the servo valve 20 flows into the supply port Ps of the servo valve 20. That is, the fluid flows from the supply port Ps into the servo valve 20 (from the lower side of the paper surface to the upper side of the paper surface in FIG. 1B). The flow rate of the fluid flowing into the servo valve 20 is controlled by the servo valve 20. Then, the fluid of the controlled controlled flow rate flows out from the control port Pc of the servo valve 20. That is, a fluid with a controlled controlled flow rate flows from the control port Pc to the control pressure chamber 10B of the cylinder 10 (from the upper side of the paper surface to the lower side of the paper surface in FIG. 1B).

The fluid that branches and flows into the constant pressure flow path 33 on the upstream side of the servo valve 20 is divided into a flow that branches to the compensation flow path 32 and a flow that flows directly through the constant pressure flow path 33 on the upstream side of the throttle mechanism 35. Divide. The fluid flowing through the compensation flow path 32 is adjusted to the compensation flow rate by the throttle mechanism 35 and joins the control flow path 31. As a result, the supply amount of the fluid supplied from the control flow path 31 to the control pressure chamber 10B is supplemented, and the total amount of the fluid of the control flow rate from the control flow path 31 and the compensation flow rate from the compensation flow path 32 is controlled. It is supplied to the pressure chamber 10B. As a result, the pressure in the control pressure chamber 10B rises, and the piston 12 advances and moves. The fluid branched into the constant pressure flow path 33 is supplied to the constant pressure chamber 10A of the cylinder 10 while being adjusted to a constant pressure.

Subsequently, the flow of the fluid at the time of exhaust when the fluid is exhausted from the control pressure chamber 10B will be described. In FIG. 2, the direction in which the fluid flows through the control flow path 31 at the time of exhaust is indicated by a dotted arrow. The direction in which the fluid flows through the compensation flow path 32 and the constant pressure flow path 33 at the time of exhaust is the same as that at the time of supply, and thus the illustration is omitted. At the time of exhaust, in the control flow path 31, the fluid flowing out from the control pressure chamber 10B flows into the control port Pc of the servo valve 20. That is, the fluid flows from the control port Pc to the servo valve 20 (from the lower side of the paper surface to the upper side of the paper surface in FIG. 1B). The fluid flowing into the servo valve 20 is exhausted into the atmosphere from the exhaust port Ex. By exhausting the fluid from the control pressure chamber 10B into the atmosphere in this way, the pressure in the control pressure chamber 10B is reduced, and the piston 12 regresses.

At the time of exhaust, the fluid flows in the constant pressure flow path 33 and the compensation flow path 32 in the same manner as in the case of supply. Here, the fluid flowing through the compensation flow path 32 joins the control flow path 31 at the compensation flow rate adjusted by the throttle mechanism 35, but since the compensation flow rate is small as described later, the fluid flows from the control pressure chamber 10B. The effect of the compensation flow rate on the exhaust of the fluid can be ignored.

Next, the conventional problem caused by the consumption in the system of the actuator system and the action and effect of the actuator system 1 according to the present embodiment on this problem will be described. First, the conventional problems will be described with reference to FIG. In the actuator system 1, for example, as shown in FIG. 2, consumption L1 in the servo valve 20 or consumption L2 in the cylinder 10 may occur.

The consumption L1 is consumption caused by the fluid flowing from the supply port Ps in the servo valve 20 not flowing to the control port Pc but flowing to the exhaust port Ex and being exhausted to the atmosphere. For example, when consumption L1 occurs, the flow rate of the fluid flowing from the supply port Ps to the control port Pc in the servo valve 20 decreases. That is, the control flow rate supplied from the control port Pc to the control pressure chamber 10B is reduced. Further, the consumption L2 is consumption caused by exhausting the fluid in the gap between the housing 11 of the cylinder 10 and the head portion 12b of the piston 12 into the atmosphere. When such consumption L2 occurs, the fluid in the control pressure chamber 10B decreases. It should be noted that such consumption L2 is consumption resulting from the use of the fluid from the supply unit 40 to form the air bearing in the cylinder 10.

Therefore, due to these consumptions L1, L2, etc., the pressure in the control pressure chamber 10B cannot be appropriately increased, and the thrust of the fluid pressure actuator may decrease. Therefore, in the conventional actuator system, it is necessary to increase the capacity of the servo valve 20 itself to supply more fluid in consideration of consumption L1, L2, etc., and there is a problem that the servo valve 20 becomes large. rice field.

On the other hand, with reference to FIG. 4, the flow of the fluid with respect to the control pressure chamber 10B in the actuator system 1 according to the present embodiment will be described. FIG. 4 is a diagram showing the flow of fluid with respect to the control pressure chamber 10B. In FIG. 4, the flow of the fluid with respect to the constant pressure chamber 10A is omitted. That is, the constant pressure flow path 33 is omitted, and only the control flow path 31 and the compensation flow path 32 are shown. Further, although not shown in FIG. 4, in reality, as described above, the constant pressure flow path 33 is connected at a position upstream of the servo valve 20 of the control flow path 31, and the constant pressure flow path 33 is connected. The compensation flow path 32 branches from 33. As shown in FIG. 4, in the actuator system 1, _{not only the control flow rate Q in 2} (i) from the control flow path 31 but also the compensation flow rate Q in ₁ (φd) of the compensation flow path 32 is supplied to the control pressure chamber 10B. There is. Therefore, for example, even when consumption L1, L2 or the like occurs, the consumption flow rate of consumption L1, L2 or the like is not increased by increasing _{the capacity of the servo valve 20 itself to increase the control flow rate Qin2 itself from the control flow path 31.} Can be supplemented by the filling flow path 32. As a result, it is possible to suppress a decrease in the obtained thrust without increasing the size of the servo valve 20 in order to increase the control flow rate Q in _{2 (i).} As a result, it is possible to suppress a decrease in the thrust obtained while reducing the size. The control flow rate Q in ₂ (i) depends on, for example, the current i of the servo valve 20 and the like. Further, the compensation flow rate Q in ₁ (φd) depends on the hole diameter φd at the center of the orifice 36, for example, when the throttle mechanism 35 is an orifice 36.

Further, the throttle mechanism 35 may set the adjustment range of the _{compensation flow rate Q in 1 (φd) as follows in order to increase the pressure P 1} in the control pressure chamber 10B to surely obtain the target thrust. Hereinafter, with reference to FIG. 4, the supplementary flow rate Q in ₁ (φd _{) when the consumption flow rate Q out} (s) of consumption L1 and the consumption flow rate Q _out (h) of consumption L2 occur as the consumption flow rate in the system of the actuator system 1. ) Will be described as an example of the adjustment range. The consumption flow rate Q _out (s) depends on the volume s of the structural gap of the servo valve 20, and the consumption flow rate Q _out (h) is between the housing 11 of the cylinder 10 and the head portion 12b of the piston 12. It depends on the volume h of the void and the like.

In this case, in the throttle mechanism 35, for example, the sum of the supply amount Qs at least at the position on the upstream side of the servo valve 20 in the control flow path 31 and the compensation flow rate Q in ₁ (φd) from the compensation flow path 32 is the actuator. _{The compensation flow rate Q in 1} (φd) is adjusted so as to be larger than the _{consumption flow rate Q out} (s) and the consumption flow rate Q _out (h), which are the flow rates consumed in the system of the system 1. _{That is, in the present embodiment, the throttle mechanism 35 adjusts the compensation flow rate Q in 1} (φd) so that the relationship of the following mathematical formula (1) is established. The supply amount Qs is the amount of fluid supplied from the supply unit 40 at least before passing through the servo valve 20 in the control flow path 31, and depends on the output of the supply unit 40 and the like.

Each flow rate in the above equation (1) varies depending on the pressure _{P 1} in the control pressure chamber 10B. The throttle mechanism 35 may adjust the _{compensation flow rate Q in 1} (φd) so that the relationship of the above equation (1) holds when _{the pressure P 1} in the control pressure chamber 10B is the target pressure. The diaphragm mechanism 35, so that the pressure P ₁ in the control pressure chamber 10B relationship of the equation (1) holds at a pressure in the entire range from the pressure when the initial state to the target pressure, filling flow rate Q in ₁ (φd) may be adjusted.

Here, with respect to the supply amount Qs, the control flow rate Q in ₂ (i) flowing out of the control port Pc and being supplied to the control pressure chamber 10B is reduced by the consumption flow rate Q _out (s) of the consumption L1. As a result, the relationship of the following mathematical formula (2) is established.

Therefore, based on the mathematical formulas (1) and (2), the relation of the following mathematical formula (3), that is, the relation of the following mathematical formula (4) is established. That is, as shown in the following mathematical formula (3), the _{controlled flow rate Q in 2} (i) flowing into the control pressure chamber 10B rather than the _{consumption flow rate Q out (h) flowing out from the control pressure chamber 10B.} If the sum with the compensation flow rate Q in ₁ (φd) is larger, the pressure P ₁ in the control pressure chamber 10B can be increased, and the target thrust can be obtained.

FIG. 5 shows an example of a relationship satisfying the above mathematical formula (4). Figure 5 is a graph showing the flow characteristics of the servo valve 20 with respect to the pressure P ₁ in the control pressure chamber 10B. FIG. 5 shows a graph when the supply pressure of the fluid is adjusted to Ps [MPa] by the regulator 41. The horizontal axis of FIG. 5 indicates the pressure [MPa] in the control pressure chamber 10B, and the vertical axis of FIG. 5 indicates the flow rate [L / min] of the fluid.

Graph 5a in FIG. 5 shows the controlled flow rate Q in ₂ (i). Graph 5b of FIG. 5 shows the consumption flow rate Q _out (h) of the consumption L2. Graph 5c of FIG. 5 shows the difference obtained by subtracting the compensation flow rate Q in _{1 (φd) from the consumption flow rate Q out (h) of the consumption L2.}

As shown in the graph 5a of FIG. 5, the controlled flow rate Q in ₂ (i) by the servo valve 20 decreases in accordance with the increase in the pressure in the control pressure chamber 10B. On the other hand, as shown in graph 5b of FIG. 5, the consumption flow rate Q _out (h) increases in response to an increase in pressure in the control pressure chamber 10B. _{As a result, for example, as shown in the figure, the consumption flow rate Q out} corresponding to the pressure Pm is higher than _{the control flow rate Q in 2} (i) corresponding to the pressure Pm in the control pressure chamber 10B required to generate the target thrust. (H) has increased. In this case, the flow rate flowing into the control pressure chamber 10B is smaller than the flow rate flowing out from the control pressure chamber 10B, and the control flow rate Q in ₂ (i) alone is appropriate for achieving the pressure Pm. A fluid with a large flow rate cannot be supplied into the control pressure chamber 10B, and a target thrust cannot be generated.

On the other hand, the graph 5c is shifted downward from the graph 5b by the amount obtained by subtracting the compensation flow rate Q in _{1 (φd) from the consumption flow rate Q out (h) shown in the graph 5b.} As a result, the graph 5c is located in the region below the graph 5a. For example, at the target pressure Pm, the consumption flow rate Q _out (h) is larger than the control flow rate Q in ₂ (i). On the other hand, when the target pressure is Pm, the result of subtracting the compensation flow rate Q in _{1 (φd) from the consumption flow rate Q out} (h) is smaller than the _{control flow rate Q in 2 (i).} As a result, the flow rate flowing into the control pressure chamber 10B can be made larger than the flow rate flowing out from the control pressure chamber 10B, and a fluid having an appropriate flow rate for achieving the pressure Pm is supplied to the control pressure chamber. It can be supplied into 10B. As a result, a target thrust can be generated.

Further, if the compensation flow rate Q in ₁ (φd) is too large, the force in the control pressure chamber 10B becomes too large than the force in the constant pressure chamber 10A, and the piston 12 remains moving and cannot move backward. In some cases. Therefore, it is sufficient for the compensation flow rate Q in ₁ (φd) if the flow rate flowing into the control pressure chamber 10B is larger than the flow rate flowing out from the control pressure chamber 10B at the target pressure (that is, the consumption flow rate). It suffices that the value obtained by subtracting the compensation flow rate Q in _{1 (φd) from Q out (h) is slightly larger than the control flow rate Q in 2} (i)), for example, a small flow rate of 2 to 10 L / min. Further, the compensation flow rate Q in ₁ (φd) may be adjusted so that the difference between the pressure in the constant pressure chamber 10A and the pressure in the control pressure chamber 10B is, for example, 0.1 MPa or less.

As described above, according to the actuator system 1 according to the present embodiment, the supply amount of the fluid supplied from the control flow path 31 to the control pressure chamber 10B is supplemented by the compensation flow path 32. Therefore, for example, even when the fluid is consumed in the system of the actuator system 1, the shortage of the consumed fluid is supplemented by the compensation flow path 32 without increasing the supply amount itself from the control flow path 31. be able to. As a result, it is possible to suppress a decrease in the obtained thrust without increasing the size of the servo valve 20 in order to increase the supply amount from the control flow path 31. From the above, it is possible to suppress a decrease in the thrust obtained while reducing the size.

Further, according to the actuator system 1, fluid is supplied from the constant pressure flow path 33 to the constant pressure chamber 10A of the cylinder 10. On the other hand, fluid is supplied to the control pressure chamber 10B of the cylinder 10 from the control flow path 31 and the compensation flow path 32. As a result, even when the fluid is consumed in the system of the actuator system 1, for example, the fluid is consumed by the supply of the fluid from the compensation flow path 32 without increasing the supply amount itself from the control flow path 31. By compensating for the shortage of the fluid, the amount of the fluid that contributes to the pressure in the control pressure chamber 10B can be secured. As a result, it is possible to suppress a decrease in the obtained thrust without increasing the size of the servo valve 20 in order to increase the supply amount from the control flow path 31. From the above, it is possible to suppress a decrease in the thrust obtained while reducing the size.

Further, according to the actuator system 1, by compensating the flow rate _{Q in1 (φd)} is adjusted, the sum of the supply amount Qs and compensating flow rate _{Q in1 (φd)} is the flow consumption _{Q out} (s), flow consumption It is more than the total with Q _{out (h).} As a result, the fluid consumed in the system of the actuator system 1 ensures that the amount of fluid insufficient to obtain the target thrust is supplemented by the compensation flow rate Q in ₁ (φd), so that the target thrust is surely obtained. Obtainable.

Further, according to the actuator system 1, the compensation flow rate Q in ₁ (φd) can be adjusted as a variable amount by the throttle mechanism 35. Thus, even if there are variations in flow consumption _{Q out} (s), it can be adjusted arbitrarily padding flow _{Q in1 (φd)} in accordance with the consumption rate _{Q out} (s). Therefore, the performance variation due to the individual difference of the consumption flow rate Q _{out (s) of the actuator system 1 is suppressed.} When it is necessary to use a plurality of actuator systems 1 in combination and control them at the same time, the performance difference in each actuator system 1 can be reduced, and better performance can be expected as a system.

(Second Embodiment)
Next, the actuator system 1A according to the second embodiment will be described with reference to FIG. The actuator system 1A has the same elements and structures as the actuator system 1 according to the first embodiment. Therefore, the same elements and structures as those of the actuator system 1 according to the first embodiment are designated by the same reference numerals, detailed description thereof will be omitted, and parts different from those of the first embodiment will be described.

FIG. 6 is a schematic configuration diagram showing the actuator system 1A according to the second embodiment, and is a diagram corresponding to FIG. As shown in FIG. 6, the actuator system 1A according to the present embodiment includes an exhaust flow path 34 (fourth flow path) in addition to the control flow path 31, the constant pressure flow path 33, and the compensation flow path 32. Therefore, it is different from the actuator system 1 according to the first embodiment. In the present embodiment, the upstream side and the downstream side in each flow path are the upstream side and the downstream side in the direction in which the fluid flows from the supply unit 40 side to the constant pressure chamber 10A side, the control pressure chamber 10B side, or the atmosphere side. Is shown.

One end of the exhaust flow path 34 is connected to the control flow path 31, and the other end is communicated with the low pressure side. The low pressure side indicates a pressure side lower than the pressure of the fluid in the exhaust flow path 34, and in the present embodiment, for example, the atmospheric side. The exhaust flow path 34 is connected to at least downstream of the servo valve 20 in the control flow path 31. The exhaust flow path 34 is connected, for example, between the servo valve 20 in the control flow path 31 and the confluence point of the constant pressure flow path 33 in the control flow path 31. The exhaust flow path 34 may be connected to, for example, the confluence point with the constant pressure flow path 33 in the control flow path 31, and the confluence point with the constant pressure flow path 33 in the control flow path 31 and the control pressure chamber 10B. It may be connected in between.

The exhaust flow path 34 exhausts (exhausts) a part of the fluid flowing through the control flow path 31 to the low pressure side (in the present embodiment, the atmosphere side). The exhaust flow path 34 exhausts a part of the fluid after the flow rate is controlled by the servo valve 20 to the atmosphere side when the fluid is supplied to the control pressure chamber 10B, for example. Further, the exhaust flow path 34 exhausts a part of the fluid before flowing into the servo valve 20 from the control pressure chamber 10B to the atmosphere side at the time of exhausting the fluid from the control pressure chamber 10B, for example.

The exhaust flow path 34 is provided with a throttle mechanism 35A (exhaust adjustment mechanism). The throttle mechanism 35A adjusts the exhaust flow rate (exhaust flow rate) of the fluid to be exhausted to the atmosphere side to a predetermined exhaust flow rate. The throttle mechanism 35A is a mechanism having resistance that causes a pressure loss in the flow of the fluid, like the throttle mechanism 35 described above. The throttle mechanism 35A throttles the flow rate of the fluid and causes a pressure difference before and after the flow rate (upstream side and downstream side of the throttle mechanism 35A in the exhaust flow path 34).

The exhaust flow rate adjusted by the throttle mechanism 35A may be a fixed amount or a variable amount. The exhaust flow rate adjusted by the throttle mechanism 35A may be preset, and is a control device (not shown) so as to have a predetermined set value according to a state (for example, consumption flow rate, pressure, etc.) in the actuator system. It may be controlled by such as. As the diaphragm mechanism 35A, for example, the configurations shown in FIGS. 3A to 3D, or various other configurations can be adopted as in the diaphragm mechanism 35.

The exhaust flow path 34 adjusts the exhaust flow rate of the fluid to a predetermined exhaust flow rate by reducing the exhaust flow rate of the fluid by the throttle mechanism 35A. As a result, the exhaust flow path 34 is adjusted so that the flow rate of the fluid in the control pressure chamber 10B, that is, the pressure in the control pressure chamber 10B becomes an appropriate value.

Next, with reference to FIG. 7, the operation and effect of the actuator system 1A including the exhaust flow path 34 in addition to the filling flow path 32 will be described in more detail. FIG. 7 is a graph showing the pressure characteristics of the actuator system 1A. The pressure characteristic of the actuator system 1A indicates a change in pressure in the control pressure chamber 10B of the cylinder 10 in response to an input signal to the servo valve 20. The pressure in the control pressure chamber 10B corresponds to the thrust generated in the cylinder 10. The horizontal axis of FIG. 7 indicates a current value [mA] as an input signal, and the vertical axis of FIG. 7 indicates a pressure [MPa].

Graph 7a of FIG. 7 shows the pressure characteristics when the fluid is not filled by the filling flow path 32 and the fluid is not exhausted by the exhaust flow path 34 (hereinafter, also referred to as “normal state”). Graph 7b of FIG. 7 shows the pressure characteristics when the fluid is replenished by the replenishment flow path 32 (hereinafter, also referred to as “replenishment state”). Graph 7c of FIG. 7 shows the pressure characteristics when the fluid is exhausted through the exhaust flow path 34 (hereinafter, “exhaust state”).

As shown in graphs 7a to 7c of FIG. 7, the actuator system 1A receives a pressure in the control pressure chamber 10B (hereinafter, “) according to a current (hereinafter, also referred to as“ input current ”) input to the servo valve 20. (Also called "thrust") changes. As shown in the graph 7b of FIG. 7, in the filled state, the characteristic is such that a lower pressure is lifted as compared with the normal state. As shown in the graph 7c of FIG. 7, in the exhaust state, the pressure characteristic is shown so that the maximum pressure becomes smaller than in the normal state.

Generally, the error factors of the pressure characteristics in the actuator system include the conductance error of each flow path and the performance error of the servo valve itself. Due to these factors, there are differences and performance variations in output characteristics such as flow rate characteristics and pressure characteristics in the actuator system.

In particular, when a plurality of actuator systems are used in combination, the performance difference between the actuators may deteriorate the performance of the system as a whole. Therefore, in general, it is desirable to combine the actuators in a state where the performance difference between the actuators is as small as possible.

Here, as described above, when only the fluid is replenished by the replenishment flow path 32 without exhausting the fluid through the exhaust flow path 34, as shown in the graph 7b of FIG. 7, as compared with the normal state. Therefore, the thrust on the low pressure side is raised. That is, the pressure characteristic can be adjusted by increasing the compensation flow rate. However, the adjustment of the pressure characteristic with respect to the input current is limited only by the filling of the fluid by the filling flow path 32.

On the other hand, when not only the fluid is filled by the filling flow path 32 but also the fluid is exhausted by the exhaust flow path 34, the characteristics on the high pressure side can be suppressed by the adjustment. That is, the graph of pressure characteristics can be raised on the low pressure side as shown in graph 7b of FIG. 7, or pushed down on the high pressure side as shown in graph 7c of FIG. 7. As a result, output characteristics such as flow rate characteristics and pressure characteristics can be arbitrarily adjusted within a certain range.

As described above, also in the present embodiment, the shortage due to the consumption flow rate can be compensated by the compensation flow path 32 without increasing the supply amount itself from the control flow path 31. As a result, it is possible to suppress a decrease in the obtained thrust without increasing the size of the servo valve 20 in order to increase the supply amount from the control flow path 31. From the above, it is possible to suppress a decrease in the thrust obtained while reducing the size.

Further, according to the actuator system 1A according to the present embodiment, the supply amount of the fluid supplied from the control flow path 31 to the control pressure chamber 10B is supplemented by the compensation flow path 32, while the throttle mechanism 35A of the exhaust flow path 34 The exhaust flow rate of the fluid exhausted from the control flow path 31 to the low pressure side can be adjusted. As a result, it becomes possible to easily adjust the output characteristics such as the flow rate characteristic and the pressure characteristic in the actuator system 1A.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and the gist described in each claim may be modified or applied to others without changing the gist.

For example, in the above embodiment, the actuator system 1 is provided with the manifold block 30, but the manifold block 30 may not be provided. For example, the cylinder 10 and the servo valve 20 are directly fixed and integrated. May be. Further, the control flow path 31, the compensation flow path 32, and the constant pressure flow path 33 may be composed of a member or the like different from the manifold block 30, or may be composed of, for example, a pipe or the like. Further, the control flow path 31, the compensation flow path 32, and the constant pressure flow path 33 may be formed in the cylinder 10 or the servo valve 20.

Further, in the above embodiment, the control flow path 31 is connected to the supply unit 40, the constant pressure flow path 33 branches from the control flow path 31, and the compensation flow path 32 further branches from the constant pressure flow path 33. , Not limited to this. For example, the control flow path 31 and the constant pressure flow path 33 may be directly connected to the supply section 40, respectively, and at least one of the control flow path 31 and the constant pressure flow path 33 and the supply section 40 are different from each other such as an introduction flow path. It may be connected via a flow path. Further, the constant pressure flow path 33 may be connected to the supply unit 40 instead of the control flow path 31, and the control flow path 31 may branch from the constant pressure flow path 33. Further, the regulator 41 may be provided in the constant pressure flow path 33.

Further, the filling flow path 32 is said to merge with the control flow path 31, but the present invention is not limited to this. The replenishment flow path 32 may be directly connected to the control pressure chamber 10B, for example, as long as the fluid can be supplied at a position where the supply amount from the control flow path 31 can be replenished.

In the above embodiment, the exhaust flow path 34 is connected to at least downstream of the servo valve 20 in the control flow path 31, but the present invention is not limited to this. For example, the exhaust flow path 34 may be connected to the position of the servo valve 20. Specifically, the exhaust flow path 34 may be integrated with the servo valve 20.

The destination where the fluid is exhausted by the exhaust flow path 34 may be on the lower pressure side than the pressure of the fluid in the exhaust flow path 34, and is not limited to the atmospheric side, and may be in a vacuum state, for example.

1,1A ... Actuator system, 10 ... Cylinder (fluid pressure actuator), 10A ... Constant pressure chamber, 10B ... Control pressure chamber, 31 ... Control flow path (first flow path), 32 ... Compensation flow path (second flow path), 33 ... constant pressure flow path (third flow rate), 34 ... exhaust flow rate (fourth flow path), 35 ... throttle mechanism (adjustment mechanism), 35A ... throttle mechanism (discharge adjustment mechanism), 40 ... supply unit (supply source) ), Qs ... Supply amount, Q in ₁ (φd) ... Compensation flow rate, Q _out (s), Q _out (h) ... Consumption flow rate.

Claims (3)

An actuator system equipped with a fluid pressure actuator that generates thrust when fluid is supplied.
A switching unit for controlling the amount of fluid supplied from the supply source is provided, and a first flow path for supplying the fluid to the fluid pressure actuator, and
A second flow path that is connected in parallel with the first flow path and supplements the supply amount of the fluid supplied from the first flow path to the fluid pressure actuator.
A third flow path for supplying the fluid to the fluid pressure actuator is provided.
The second flow path branches from the third flow path, and is branched from the third flow path.
The fluid pressure actuator has a first supplied portion to which the fluid is supplied from the first flow path and the second flow path, and a second supplied portion to which the fluid is supplied from the third flow path. Have and
The switching unit controls the supply amount of the fluid so that the difference between the pressure of the first supplied portion and the pressure of the second supplied portion of the fluid pressure actuator becomes a desired magnitude.
The second flow path has a drawing mechanism and has a drawing mechanism.
The throttle mechanism compensates for the shortage of the supply amount so as to eliminate the difference obtained by subtracting the supply amount of the fluid in the first flow path from the flow rate of the fluid that needs to be supplied to the first supply unit. The fluid of the supplementary flow rate is supplied from the second flow path,
The shortfall, Ru flow consumption der caused by the consumption of the fluid in the switching unit and the hydraulic actuator, the actuator system. The actuator system according to claim 1, wherein the throttle mechanism adjusts the compensation flow rate as a variable amount. A fourth flow path, which is connected to the position of the switching portion in the first flow path or at least downstream of the switching portion and discharges the fluid in the first flow path to the low pressure side, is further provided.
The actuator system according to claim 1 or 2, wherein the fourth flow path has a discharge throttle mechanism for adjusting the discharge flow rate of the fluid.

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