Flow controller and driving device having the same

Abstract

A flow controller (12) and a drive device (10) comprising: a cylinder flow path (21) connected to a cylinder (14); a main flow path (22) for supplying and discharging air to the cylinder (14); a secondary flow path (23) having a first throttle valve (24) and allowing exhaust air from the cylinder (14) to pass through at a flow rate smaller than that of the main flow path (22); a switching valve (26) switching between a first position for connecting the cylinder flow path (21) with the main flow path (22) and a second position for connecting the cylinder flow path (21) with the secondary flow path (23); and a pilot air adjustment unit (30) for directing a portion of the exhaust air from the cylinder (14) as pilot air to the switching valve (26).

Description

Technical Field

[0001] The invention relates to a flow controller of a cylinder and a driving device equipped with the flow controller. Background Art

[0002] Conventionally, a shock relieving mechanism is used to relieve the impact at the stroke end by installing a cushioning material such as rubber or polyurethane or an oil damper at the end of the cylinder. However, the shock relieving mechanism that mechanically relieves the impact of the cylinder has a limited number of operations and requires regular maintenance.

[0003] In order to eliminate such incompatibility, Japanese Patent No. 5578502 discloses a speed controller (flow rate controller) that reduces the operating speed of the cylinder by throttling the exhaust gas from the cylinder near the end of the stroke.

[0004] Conventional flow controllers gradually exhaust pilot air through a throttle valve, and switch the switching valve to exhaust throttling when the pilot pressure falls below a specified value. However, it has been found that when the pressure acting on the throttle valve falls below a specified pressure, the flow of pilot air through the throttle valve decreases sharply, and the timing of the switching action becomes unstable. Summary of the invention

[0005] Therefore, an object of one aspect of the present invention is to provide a flow controller capable of stabilizing the timing of switching operations and a driving device including the flow controller.

[0006] One viewpoint of the present invention is a flow controller comprising: a cylinder flow path connected to a port of a cylinder; a main flow path for supplying and discharging air to the cylinder flow path; a secondary flow path which is arranged in parallel with the main flow path and has a first throttle valve which throttles the flow rate of air to a flow rate smaller than that of the main flow path; a switching valve which is connected to the cylinder flow path, the main flow path and the secondary flow path and switches to a first position which connects the cylinder flow path with the main flow path and a second position which connects the cylinder flow path with the secondary flow path; and a pilot air adjustment unit which guides a portion of the exhaust air of the cylinder flow path as pilot air to the switching valve, the pilot air adjustment unit having a second throttle valve which limits the inflow speed of the pilot air into the switching valve, the switching valve switching from the first position to the second position by the increase in the pressure of the pilot air.

[0007] Another aspect of the present invention is a drive device comprising: a high-pressure air supply source, which supplies high-pressure air to a cylinder; an exhaust port, which discharges the exhaust air of the cylinder; a cylinder flow path, which is connected to a port of the cylinder; a main flow path, which supplies and discharges air to the cylinder flow path; a secondary flow path, which is arranged in parallel with the main flow path and has a first throttle valve, which throttles the flow rate of air to a smaller flow rate than the main flow path; a switching valve, which is connected to the cylinder flow path, the main flow path and the secondary flow path, and switches to a first position that connects the cylinder flow path with the main flow path and a first position that connects the cylinder flow path with the main flow path. a flow controller having a pilot air adjustment unit that directs a portion of the exhaust air of the cylinder flow path as pilot air to the switching valve; and an action switching valve that is connected to the high-pressure air supply source, the exhaust port and one end of the main flow path, and switches the high-pressure air supply source or the exhaust port to be connected to the main flow path, the pilot air adjustment unit having a second throttle valve that limits the inflow speed of the pilot air into the switching valve, and the switching valve is switched from the first position to the second position by the increase in the pressure of the pilot air.

[0008] According to the flow controller of the above-described viewpoint and the driving device including the flow controller, the timing of the switching operation can be stabilized. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a perspective view of a cylinder equipped with a flow controller according to an embodiment.

[0010] Figure 2 It is a fluid circuit diagram of a flow controller and a driving device according to an embodiment.

[0011] Figure 3A It is expressed from the valve port side Figure 1 A three-dimensional diagram of the flow controller, Figure 3B It is shown from the cylinder port side Figure 1 A stereogram of a flow controller.

[0012] Figure 4 It means in Figure 3B A cross-sectional view of a section cut along line IV-IV parallel to the upper surface.

[0013] Figure 5 It means in Figure 3A The cross-sectional view is a cross-sectional view of a section cut parallel to the side surface at the position of the VV line.

[0014] Figure 6 It means in Figure 4A cross-sectional view of a section cut parallel to the front surface along the VI-VI line.

[0015] Figure 7 Yes means Figure 2 A fluid circuit diagram showing a state in which the switching valve on the rod side is switched to the second position. DETAILED DESCRIPTION

[0016] Hereinafter, preferred embodiments of the present invention will be listed and described in detail with reference to the attached drawings.

[0017] like Figure 1 As shown, the air cylinder 14 is a double-acting air cylinder used in an automatic equipment line, etc. The air cylinder 14 includes a cylindrical cylinder tube 74, a top end cover 76 that closes the top end of the cylinder tube 74, and a rod side end cover 78 that closes the rod side end of the cylinder tube 74. The cylinder tube 74, the top end cover 76, and the rod side end cover 78 are tightened and connected in the axial direction by a plurality of connecting rods 80 and fixing bolts 82.

[0018] like Figure 2 As shown, a piston 16 for partitioning a cylinder chamber 18 and a piston rod 17 connected to the piston 16 are provided inside the cylinder tube 74. A top side port 76a is provided in a top side pressure chamber 18a on the top side of the piston 16, and a rod side port 78a is provided in a rod side pressure chamber 18b on the rod side of the piston 16. Figure 1 As shown, a top-side port 76 a is provided on the top-side end cover 76 , and a rod-side port 78 a is provided on the rod-side end cover 78 .

[0019] like Figure 2 As shown, the cylinder 14 is driven by a drive device 10, which has a flow controller 12 on the top side and the rod side, an action switching valve 34 and a high-pressure air supply source 36. Figure 1 As shown, the top side flow controller 12 is connected to the top side port 76a of the cylinder 14 via the top side piping 20A, and the rod side flow controller 12 is connected to the rod side port 78a via the rod side piping 20B. The top side piping 20A and the rod side piping 20B are included in the cylinder flow path 21 that connects the cylinder 14 and the flow controller 12, and the high-pressure air is introduced into the cylinder 14 and the air is exhausted from the cylinder 14 via the cylinder flow path 21.

[0020] like Figure 2As shown, the flow controller 12 on the top side includes a main flow path 22 connected to the cylinder flow path 21, a secondary flow path 23 arranged in parallel with the main flow path 22, and a detour flow path 28 connecting the main flow path 22 and the cylinder flow path 21. A switching valve 26 is connected between the main flow path 22 and the secondary flow path 23 and the cylinder flow path 21. The switching valve 26 is a so-called three-way valve, and is connected to the cylinder flow path 21, the main flow path 22, and the secondary flow path 23. A third throttle valve 25 for adjusting the flow rate of air is provided in the main flow path 22. The third throttle valve 25 can adjust the operating speed of the cylinder 14 by variably limiting the flow rate of the exhaust air flowing in the main flow path 22.

[0021] On the other hand, the secondary flow path 23 is provided with a first throttle valve 24 that variably limits the flow rate of exhaust air flowing in the secondary flow path 23. The first throttle valve 24 is configured to throttle the flow rate of exhaust air more strongly than the third throttle valve 25 of the main flow path 22. An exhaust port 24a is connected to the downstream side of the first throttle valve 24, and the exhaust air that has passed through the first throttle valve 24 is discharged from the exhaust port 24a.

[0022] The bypass flow path 28 has one end connected to the main flow path 22 between the third throttle valve 25 and the valve port 12a, and the other end connected to the cylinder flow path 21, and the bypass flow path 28 bypasses the third throttle valve 25 and the switching valve 26 to connect the main flow path 22 and the cylinder flow path 21. The bypass flow path 28 is provided with a shuttle valve 32 having a first inlet 32a, a second inlet 32b, and an outlet 32c. The first portion 28a of the bypass flow path 28 is connected to the first inlet 32a of the shuttle valve 32, the second portion 28b of the bypass flow path 28 is connected to the outlet 32c, and the switching valve 26 is connected to the second inlet 32b via the pilot air adjustment unit 30.

[0023] When the pressure of the main flow path 22 is higher than the pressure of the cylinder flow path 21, the shuttle valve 32 blocks the second inlet 32b and communicates the first inlet 32a with the outlet 32c, and introduces the high-pressure air of the main flow path 22 into the cylinder flow path 21 through the detour flow path 28. On the other hand, when the pressure of the main flow path 22 is lower than the pressure of the cylinder flow path 21, the shuttle valve 32 blocks the first inlet 32a and communicates the second inlet 32b with the outlet 32c, and guides the exhaust air of the cylinder flow path 21 to the pilot air adjustment unit 30 as the pilot air.

[0024] The pilot air adjustment unit 30 is disposed between the second inlet 32b of the shuttle valve 32 and the switching valve 26. The pilot air adjustment unit 30 includes a second throttle valve 31a and a check valve 31b connected in parallel with the second throttle valve 31a. The downstream sides of the second throttle valve 31a and the check valve 31b are connected to the piston unit 45 (see Figure 4The pilot air passing through the second throttle valve 31a drives the switching valve 26 to switch the switching valve 26 from the first position, where the exhaust air flows from the cylinder flow path 21 to the main flow path 22, to the second position, where the exhaust air flows from the cylinder flow path 21 to the secondary flow path 23 (see Figure 7 The switching valve 26 on the left side of the .

[0025] The check valve 31b is connected in a direction that allows the air flowing from the switching valve 26 toward the shuttle valve 32 to pass. When the pressure of the exhaust air of the cylinder flow path 21 decreases, the check valve 31b discharges the pilot air of the switching valve 26 to the cylinder flow path 21. With the discharge of the pilot air, the switching valve 26 is returned to the first position from the second position by the elastic force of the return spring 26a of the switching valve 26.

[0026] Since the rod-side flow controller 12 connected to the rod-side pipe 20B and the top-side flow controller 12 have substantially the same structure, the same components as those of the top-side flow controller 12 are denoted by the same reference numerals and detailed description thereof is omitted.

[0027] Next, the structure of the operation switching valve 34 connected to the top side flow controller 12 and the rod side flow controller 12 will be described. One end of the third pipe 27A is connected to the valve port 12a of the top side flow controller 12, and one end of the fourth pipe 27B is connected to the valve port 12a of the rod side flow controller 12. The operation switching valve 34 is connected to the other ends of the third pipe 27A and the fourth pipe 27B.

[0028] The action switching valve 34 is a five-port valve that electrically switches the connection destination of the high-pressure air, and has a first port 34a to a fifth port 34e. The first port 34a is connected to the third pipe 27A, and the second port 34b is connected to the fourth pipe 27B. The third port 34c and the fifth port 34e are connected to the exhaust port 38, and the fourth port 34d is connected to the high-pressure air supply source 36.

[0029] The action switching valve 34 is Figure 2 The first position shown connects the first port 34a to the fourth port 34d and the second port 34b to the fifth port 34e. Thus, the actuation switching valve 34 connects the high pressure air supply source 36 to the top port 76a and the exhaust port 38 to the rod port 78a.

[0030] In addition, the operation switching valve 34 communicates the first port 34a with the third port 34c and communicates the second port 34b with the fourth port 34d in the second position. In this way, the operation switching valve 34 communicates the high-pressure air supply source 36 with the rod-side port 78a and communicates the exhaust port 38 with the top-side port 76a.

[0031] The circuit structure of the driving device 10 of the present embodiment is configured as described above. Hereinafter, the specific structure of the flow controller 12 will be described.

[0032] like Figure 3A and Figure 3B As shown, the flow controller 12 includes a flat box-shaped housing 40. The housing 40 contains the cylinder flow path 21, the main flow path 22, the secondary flow path 23, the bypass flow path 28, the first throttle valve 24, the switching valve 26, the pilot air adjustment unit 30, the third throttle valve 25, and the shuttle valve 32. A plurality of holes are formed on the upper surface 40a of the housing 40, and the first throttle valve 24, the third throttle valve 25, the pilot air adjustment unit 30, and the shuttle valve 32 are inserted into the holes. Figure 5 As shown, the third throttle valve 25 is composed of a needle valve provided in the middle of the internal flow path 50a (main flow path 22) connecting the valve port 12a and the switching valve 26, and can variably adjust the flow rate by rotating the adjustment screw at the upper end.

[0033] like Figure 6 As shown in FIG. 1 , the pilot air adjustment unit 30 is composed of a throttle valve 70 with a check valve, and the throttle valve 70 with a check valve is formed integrally with a check valve 31b and a second throttle valve 31a. The flow rate of the second throttle valve 31a can be changed by rotating a screw mechanism 72. In addition, the check valve 31b has an elastic valve member 71, which allows air flowing from the internal flow path 30a to the internal flow path 30b to pass through, and blocks air flowing in the opposite direction.

[0034] The shuttle valve 32 includes a shuttle valve installation hole 61 having an inclined portion 61a whose top end tapers in diameter. A first inlet 32a of the shuttle valve 32 is formed on the side of the shuttle valve installation hole 61 and on the inclined portion 61a. In addition, a second inlet 32b of the shuttle valve 32 is formed on the side of the shuttle valve installation hole 61 and at a position higher than the first inlet 32a. In addition, an outlet 32c of the shuttle valve 32 is formed at the lower end of the shuttle valve installation hole 61.

[0035] The shuttle valve 32 further includes a flow path member 60 inserted into the shuttle valve installation hole 61 and a valve element 66 disposed between the flow path member 60 and the inclined portion 61a. The flow path member 60 includes a closing portion 63 formed at an upper end with an inner diameter substantially the same as that of the shuttle valve installation hole 61. The closing portion 63 closes the upper end of the shuttle valve installation hole 61. The tube portion 62 extends from the closing portion 63 of the flow path member 60 toward the lower end of the shuttle valve installation hole 61.

[0036] The tube portion 62 is a tubular member having a diameter smaller than the inner diameter of the shuttle valve installation hole 61, and the lower end portion (top end portion) of the tube portion 62 is opened near the outlet 32c, and a vent hole 64 is formed near the base end portion of the tube portion 62 to penetrate the tube portion 62 in the radial direction. In addition, a partition portion 65 and a gasket 65a are provided at the outer peripheral portion of the tube portion 62 and between the outlet 32c and the second inlet 32b, which are in close contact with the shuttle valve installation hole 61. The partition portion 65 and the gasket 65a airtightly partition the second inlet 32b and the outlet 32c on the outer side of the tube portion 62.

[0037] The valve core 66 is made of an elastic member and is formed into a plate-like shape that is generally conical and protrudes downward, and has a generally V-shaped cross section. The lower end side of the valve core 66 has an inclined surface that can be closely attached to the inclined portion 61a. A conical protrusion 67 that can be inserted into the tube portion 62 is formed at the center of the upper end of the valve core 66. Figure 6 , the lower end side of the valve core 66 is in close contact with the inclined portion 61a, the first inlet 32a and the outlet 32c are airtightly closed, and the second inlet 32b and the outlet 32c are connected. When the pressure on the first inlet 32a side increases, the valve core 66 rises, the protrusion 67 is inserted into the inner side of the tube portion 62, and the valve core 66 covers the tube portion 62. In this state, the valve core 66 blocks the inner side of the tube portion 62 to prevent the second inlet 32b and the outlet 32c from being connected, and the outer peripheral portion of the valve core 66 is elastically deformed along the air flow, so that the first inlet 32a and the outlet 32c are connected. That is, when the valve core 66 is displaced upward, the shuttle valve 32 opens the first part 28a and the second part 28b of the bypass flow path 28.

[0038] The first inlet 32a of the shuttle valve 32 is connected to the first portion 28a of the bypass flow path 28. Figure 4 The valve port 12a (main flow path 22) shown in FIG. Figure 6 As shown, the second inlet 32b of the shuttle valve 32 communicates with the adjacent pilot air adjustment unit 30 through the internal flow path 30b. Furthermore, the outlet 32c communicates with the cylinder port 12b (cylinder flow path 21) through the second portion 28b of the bypass flow path 28.

[0039] On the other hand, Figure 3A As shown, the first throttle valve 24 and the exhaust port 24a constitute an exhaust throttle valve formed integrally with these components, and exhaust air is discharged from the upper surface 40a shown in the figure. The flow rate of the first throttle valve 24 can be changed by turning the needle type adjustment screw exposed on the upper surface 40a.

[0040] The rear surface 40d of the housing 40 is provided with a cylinder port 12b for connecting the top side pipe 20A or the rod side pipe 20B of the cylinder 14. Figure 3B) is formed with a valve port 12a for connecting the third pipe 27A or the fourth pipe 27B. In addition, a spool guide hole 42 is formed in a manner penetrating from one side surface 40c of the housing 40 to the other side surface 40e. The switching valve 26 is provided in the spool guide hole 42.

[0041] like Figure 4 As shown in FIG. 1 , the switching valve 26 is configured as a spool valve including a spool guide hole 42 and a spool 46 accommodated in the spool guide hole 42. The spool guide hole 42 includes a spool guide portion 42a formed with a relatively small inner diameter and a piston accommodation portion 42b formed with an inner diameter larger than that of the spool guide hole 42a. The spool guide hole 42 is closed by a cap 44 that closes the end portion on the spool guide portion 42a side and a cap 48 that closes the piston accommodation portion 42b side. The cap 44 and the cap 48 are fixed to the spool guide hole 42 by a fixing clip 58a.

[0042] The spool guide portion 42a is formed with a first communicating groove 50, a second communicating groove 52, and a third communicating groove 54 formed by expanding the inner diameter in a groove shape over the entire circumference. The first communicating groove 50 is formed at a position closest to the cover 44, and communicates with the valve port 12a via an internal flow path 50a. The second communicating groove 52 is a groove formed in a portion close to the piston portion 45, and communicates with the first throttle valve 24 and the exhaust port 24a via an internal flow path 52a. The third communicating groove 54 is a groove formed between the first communicating groove 50 and the second communicating groove 52, and communicates with the cylinder port 12b via an internal flow path 54a.

[0043] The piston receiving portion 42b is formed with a larger diameter than the spool guide portion 42a, and a piston chamber 41 is formed inside. The piston chamber 41 receives the piston portion 45 of the spool 46. A return spring 26a is provided on the side 40e of the piston chamber 41 to apply force to the piston portion 45 toward the side 40c and return it to the first position. On the side 40c of the piston chamber 41, the internal flow path 30a is opened. The internal flow path 30a is connected to the pilot air adjustment portion 30.

[0044] The spool 46 is disposed in the spool guide hole 42 in a manner that allows sliding in the axial direction perpendicular to the side surfaces 40c and 40e. A spool portion 46a inserted into the spool guide hole 42 is provided on the side surface 40e of the spool 46, and a piston portion 45 for driving the spool 46 is provided on the side surface 40c of the spool 46. The piston portion 45 has a larger diameter than the spool portion 46a and is accommodated in the piston chamber 41. A gasket 56 is mounted on the outer periphery of the piston portion 45, and the piston chamber 41 is airtightly partitioned into an empty chamber on the side surface 40c and an empty chamber on the side surface 40e by the gasket 56.

[0045] The slide column portion 46a has guide end portions 46e and 46f at both ends in the axial direction. The guide end portions 46e and 46f are formed to have an outer diameter slightly smaller than the inner diameter of the slide column guide portion 42a, and guide the axial movement of the slide column 46. Gaskets 49 are provided at the guide end portions 46e and 46f, respectively, to prevent air leakage along the axial direction. A first closed wall 46c, a second closed wall 46d, and recessed portions 47a, 47b, and 47c are formed between the guide end portions 46e and 46f.

[0046] The first closing wall 46c and the second closing wall 46d are formed to have an outer diameter slightly smaller than the inner diameter of the spool guide 42a, and are provided with a gasket 49 at their outer circumferences. Figure 4 The first position shown is formed at a position where the inner wall of the slide column guide portion 42a between the second communication groove 52 and the third communication groove 54 is in close contact, and the communication between the second communication groove 52 and the third communication groove 54 is blocked. On the other hand, the second closing wall 46d is disposed farther away from the side surface 40e than the first closing wall 46c, and is located in the third communication groove 54 at the first position, allowing the third communication groove 54 to communicate with the first communication groove 50.

[0047] The second closing wall 46d is in close contact with the inner peripheral surface of the slide column guide portion 42a between the second position of the slide column 46 and the third connecting groove 54 and the first connecting groove 50, and prevents the third connecting groove 54 from communicating with the first connecting groove 50. In addition, the first closing wall 46c is located in the third connecting groove 54 at the second position, and allows the third connecting groove 54 to communicate with the second connecting groove 52.

[0048] The recess 47a is formed between the second closed wall 46d and the guide end 46e, and a flow path with a larger cross-sectional area is formed at the first position of the slide column 46, so that air can easily pass between the first connecting groove 50 and the third connecting groove 54. The recess 47b is formed between the first closed wall 46c and the second closed wall 46d. In addition, the recess 47c is formed between the first closed wall 46c and the guide end 46f, and a flow path with a larger cross-sectional area is formed between the second connecting groove 52 and the third connecting groove 54 at the second position of the slide column 46.

[0049] The specific structure of the flow controller 12 is constructed as described above. The function and operation of the driving device 10 of this embodiment will be described below. Figure 2 and Figure 7 The following description will be given by taking the working stroke in which the piston 16 moves toward the rod-side port 78 a as an example.

[0050] like Figure 2As shown in FIG. 1 , in the working stroke, the action switching valve 34 is switched to the first position, and the high-pressure air supply source 36 is connected to the third pipe 27A. The high-pressure air flows into the flow controller 12 on the top side through the valve port 12a. In the flow controller 12, the high-pressure air flows into the main flow path 22 and the detour flow path 28. The switching valve 26 is in the first position as the initial position, and the high-pressure air in the main flow path 22 flows into the cylinder flow path 21 through the switching valve 26 as shown by the arrow A1.

[0051] In addition, in the bypass flow path 28, the pressure of the first portion 28a is higher than the pressure of the second portion 28b. Figure 6 The valve core 66 of the shuttle valve 32 shown in FIG. 1 is pressed toward the upper end side, so that the first inlet 32a is connected to the outlet 32c, and the first part 28a and the second part 28b of the bypass flow path 28 are opened. Figure 2 As shown by arrow A2, the high-pressure air flows toward the cylinder flow path 21 via the bypass flow path 28. Since there is no throttle valve in the bypass flow path 28, the high-pressure air is introduced into the top port 76a of the cylinder 14 by free flow.

[0052] On the other hand, the exhaust air discharged from the rod-side pressure chamber 18b via the rod-side piping 20B flows into the flow controller 12 on the rod side. The exhaust air flows in from the cylinder port 12b of the flow controller 12. The switching valve 26 on the rod side is in the first position, the cylinder flow path 21 is connected to the main flow path 22, and the exhaust air is discharged from the exhaust port 38 through the main flow path 22 as shown by the arrow B1. At this time, the flow rate of the exhaust air is throttled by the third throttle valve 25, and the movement speed of the piston 16 of the cylinder 14 is limited by the third throttle valve 25. In this way, the flow controller 12 constitutes a speed controller of a metering output that limits the movement speed of the piston 16 by the exhaust air discharged from the cylinder 14.

[0053] In addition, in the flow controller 12 on the rod side, a part of the exhaust air flows into the second portion 28b of the bypass flow path 28 as shown by the arrow P. Figure 6 As shown, the valve core 66 of the shuttle valve 32 is forced downward, so that the first inlet 32a and the outlet 32c are blocked, and the second inlet 32b is connected to the outlet 32c. Figure 2 As shown, the exhaust air after passing through the shuttle valve 32 passes through the pilot air adjustment unit 30 as pilot air and is supplied to the switching valve 26. The flow rate of the pilot air is variably adjusted by the second throttle valve 31a.

[0054] Subsequently, the pilot air pressure of the rod-side switching valve 26 gradually increases with the movement of the piston 16. Then, when the piston 16 approaches a predetermined timing near the end of the stroke, the rod-side switching valve 26 overcomes the elastic force of the return spring 26a by the pilot air pressure and switches from the first position to the second position.

[0055] like Figure 7 As shown in FIG. 1 , in the second position of the switch valve 26 on the rod side, the cylinder flow path 21 is connected to the auxiliary flow path 23. The exhaust air from the cylinder 14 flows as shown by the arrow B2, is restricted by the first throttle valve 24 of the auxiliary flow path 23, and is discharged from the exhaust port 24a. Since the flow rate of the first throttle valve 24 is smaller than the flow rate of the third throttle valve 25, the flow rate of the exhaust air is greatly throttled when the piston 16 approaches the end of the stroke, thereby reducing the speed of the piston 16. As a result, the impact of the cylinder 14 when the piston 16 reaches the end of the stroke is alleviated.

[0056] When the piston 16 stops, the flow of exhaust air into the flow controller 12 on the rod side stops, and the pilot air of the switching valve 26 is discharged to the cylinder flow path side through the check valve 31b of the pilot air adjustment unit 30. Then, the switching valve 26 is returned to the first position by the elastic force of the return spring 26a.

[0057] Through the above, the action of the working stroke of the driving device 10 of the cylinder 14 is completed. Subsequently, the reset stroke is performed by switching the action switching valve 34 from the first position to the second position. In the reset stroke, the exhaust air flows through the flow controller 12 on the top side, and the high-pressure air flows through the flow controller 12 on the rod side. Since the action of the driving device 10 in the reset stroke is basically the same as the action of the working stroke described above, only the flow controller 12 on the top side and the flow controller 12 on the rod side are used in place, and therefore the description thereof is omitted.

[0058] The flow controller 12 and the driving device 10 of this embodiment have the following effects.

[0059] In conventional flow controllers, when the pilot air pressure of the switching valve is lower than 0.4 MPa, the flow rate of the pilot air passing through the throttle valve may decrease rapidly, so that the pilot air cannot be released and the switching valve cannot be switched at the expected timing.

[0060] In contrast, the flow controller 12 of the present embodiment includes: a cylinder flow path 21 connected to a port of the cylinder 14; a main flow path 22 for supplying and discharging air to the cylinder flow path 21; a secondary flow path 23 having a first throttle valve 24 and allowing exhaust air discharged from the cylinder 14 to pass at a flow rate smaller than that of the main flow path 22; a switching valve 26 connected between the cylinder flow path 21 and the main flow path 22 and the secondary flow path 23, and switched to a first position for connecting the cylinder flow path 21 with the main flow path 22 and a second position for connecting the cylinder flow path 21 with the secondary flow path 23; and a pilot air regulating unit 30, which introduces a portion of the exhaust air of the cylinder flow path 21 as pilot air into the switching valve 26, the switching valve 26 being switched from the first position to the second position by the increase in the pressure of the pilot air, and the pilot air regulating unit 30 having a second throttle valve 31a for limiting the inflow speed of the pilot air into the switching valve 26.

[0061] In the flow controller 12 of the present embodiment, a part of the exhaust air is used as the pilot air, and the pilot air regulator 30 functions as a speed controller that limits the metered input of the pilot air flowing into the switching valve 26. Therefore, a pressure of at least 0.4 MPa or more continuously acts on the second throttle valve 31a, thereby preventing a decrease in the flow rate of the pilot air passing through the second throttle valve 31a. As a result, in the flow controller 12, the operation timing of the switching valve 26 is stabilized.

[0062] In addition, it is also effective that the flow controller 12 of the present embodiment is connected to a cylinder having an impact mitigation structure such as an air cushion. In this case, the flow rate of air can be throttled before the impact mitigation structure is actuated, thereby reducing the load acting on the impact mitigation structure. In addition, when the cylinder is actuated at high speed, it is difficult to adjust the repulsive force of the impact mitigation structure such as the air cushion at the end of the stroke, and unintentional vibration of the piston is likely to bounce near the end of the stroke. In such a case, when the flow controller 12 is provided in the drive device 10, since the flow rate of air can be throttled before the impact mitigation structure is actuated, the action of the impact mitigation structure becomes smooth and the occurrence of bounce can be prevented.

[0063] In the above-mentioned flow controller 12, it is also possible to further include: a detour flow path 28 that bypasses the switching valve 26 and connects the cylinder flow path 21 and the main flow path 22; and a shuttle valve 32 arranged between the detour flow path 28 and the pilot air adjustment unit 30. When the pressure of the main flow path 22 is higher than the pressure of the cylinder flow path 21, the shuttle valve 32 blocks the communication between the pilot air adjustment unit 30 and the detour flow path 28, and connects the main flow path 22 with the cylinder flow path 21. When the pressure of the cylinder flow path 21 is higher than the pressure of the main flow path 22, the shuttle valve 32 blocks the communication between the main flow path 22 and the cylinder flow path 21, and connects the cylinder flow path 21 with the pilot air adjustment unit 30.

[0064] Thus, since the high-pressure air flows into the cylinder flow path 21 not only through the main flow path 22 but also through the bypass flow path 28 , it becomes easy to cope with high-speed operation of the cylinder 14 .

[0065] In the above-mentioned flow controller 12, a third throttle valve 25 for limiting the flow rate of air flowing in the main flow path 22 may be provided, and a detour flow path 28 may bypass the switching valve 26 and the third throttle valve 25 to connect the main flow path 22 and the cylinder flow path 21. In this way, by providing the third throttle valve 25, the flow rate of the exhaust air flowing in the main flow path 22 can be limited, and the movement speed of the piston 16 of the cylinder 14 can be adjusted by the third throttle valve 25. In addition, since the detour flow path 28 is provided by bypassing the switching valve 26 and the third throttle valve 25, since the high-pressure air is not limited by the flow rate of the third throttle valve 25, it becomes easy to cope with the high-speed movement of the cylinder 14.

[0066] In the above-mentioned flow controller 12, it is also possible to include a housing 40 that accommodates the switching valve 26, the pilot air adjustment unit 30, the first throttle valve 24, the detour flow path 28, and the shuttle valve 32, and the housing 40 has a valve port 12a that communicates with the main flow path 22, an exhaust port 24a that communicates with the secondary flow path 23, and a cylinder port 12b that communicates with the cylinder flow path 21. According to the above-mentioned structure, the main part of the flow controller 12 can be integrated in the housing 40. In addition, the flow controller 12 can be mounted on the cylinder 14 simply by connecting the valve port 12a and the cylinder port 12a to the piping.

[0067] In the above-mentioned flow controller 12, the switching valve 26 may also include: a slide column guide hole 42, the slide column guide hole 42 having a first communication groove 50 communicating with the valve port 12a, a second communication groove 52 communicating with the first throttle valve 24, and a third communication groove 54 communicating with the cylinder port 12b; a slide column 46, the slide column 46 is arranged in the slide column guide hole 42 in a manner that can slide in the axial direction, and is formed with a first closing wall 46c, a second closing wall 46d and recessed portions 47a, 47c, the first closing wall 46c blocking the second communication groove 52 from connecting with the third communication groove 54 at a first position The second closed wall 46d blocks the communication between the first communicating groove 50 and the third communicating groove 54 at the second position, and the recesses 47a and 47c are formed between the first closed wall 46c and the second closed wall 46c, so that the first communicating groove 50 is connected with the third communicating groove 54 at the first position, and the second communicating groove 52 is connected with the third communicating groove 54 at the second position; a return spring 26a, which applies force to the sliding column 46 toward the first position side; and a piston portion 45, which displaces the sliding column 46 to the second position under the action of the pilot air flowing in from the cylinder port 12b.

[0068] The drive device 10 described above comprises: a high-pressure air supply source 36 for supplying high-pressure air to the cylinder 14; an exhaust port 38 for discharging exhaust air from the cylinder 14; a cylinder flow path 21 connected to a port of the cylinder 14; a main flow path 22 for supplying and discharging air to the cylinder flow path 21; a secondary flow path 23 having a first throttle valve 24 and allowing exhaust air discharged from the cylinder 14 to pass at a flow rate smaller than that of the main flow path 22; a switching valve 26 connected between the cylinder flow path 21 and the main flow path 22 and the secondary flow path 23, and switching to a first position for connecting the cylinder flow path 21 with the main flow path 22 and a second position for connecting the cylinder flow path 21 with the secondary flow path 23. Two positions; a flow controller 12, the flow controller 12 has a pilot air adjustment unit 30, the pilot air adjustment unit 30 guides a part of the exhaust air of the cylinder flow path 21 as pilot air to the switching valve 26, the switching valve 26 is switched from the first position to the second position by the increase in the pressure of the pilot air, the pilot air adjustment unit 30 has a second throttle valve 31a that limits the inflow speed of the pilot air flowing into the switching valve 26; and an action switching valve 34, the action switching valve 34 is connected to the high-pressure air supply source 36, the exhaust port 38 and one end of the main flow path 22, and switches the high-pressure air supply source 36 or the exhaust port 38 to be connected to the main flow path 22.

[0069] According to the above-described drive device 10 , by providing the flow controller 12 , the operation timing of the switching valve 26 can be stabilized.

[0070] In the above-mentioned drive device 10, the flow controller 12 may be connected to the rod-side cylinder flow path 21 communicating with the top-side port 76a and the rod-side port 78a of the cylinder 14. This can mitigate the impact at the stroke end for both the working stroke and the return stroke.

[0071] Although the present invention has been described above by way of preferred embodiments, the present invention is not limited to the above embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

Claims

1. A flow controller, characterized in that: have: A cylinder flow path (21) communicating with a port of the cylinder (14); A main flow path (22) for supplying and discharging air to the cylinder flow path; A secondary flow path (23) is arranged in parallel with the primary flow path and has a first throttle valve (24) which throttles the flow rate of air to a smaller flow rate than that of the primary flow path; a switching valve (26) connected to the cylinder flow path, the main flow path, and the secondary flow path, and switched to a first position for connecting the cylinder flow path with the main flow path and a second position for connecting the cylinder flow path with the secondary flow path; as well as a pilot air regulating unit (30) for guiding a part of the exhaust air of the cylinder flow path to the switching valve as pilot air, The pilot air adjustment unit includes a second throttle valve (31a) which limits the inflow speed of the pilot air into the switching valve. When the exhaust air is discharged from the cylinder (14), the switching valve is located at the first position due to the elastic force of the return spring (26a), so that the exhaust air is discharged through the main flow path. When the pressure of the pilot air rises and becomes above the specified pressure as the piston (16) in the cylinder moves, the switching valve overcomes the elastic force of the return spring and switches from the first position to the second position, so that the exhaust air is discharged through the secondary flow path.

2. A flow controller, characterized in that: have: A cylinder flow path (21) communicating with a port of the cylinder (14); A main flow path (22) for supplying and discharging air to the cylinder flow path; A secondary flow path (23) is arranged in parallel with the primary flow path and has a first throttle valve (24) which throttles the flow rate of air to a smaller flow rate than that of the primary flow path; a switching valve (26) connected to the cylinder flow path, the main flow path, and the secondary flow path, and switched to a first position for connecting the cylinder flow path with the main flow path and a second position for connecting the cylinder flow path with the secondary flow path; a pilot air adjustment unit (30) which guides a portion of the exhaust air of the cylinder flow path to the switching valve as pilot air; a detour flow path (28) that bypasses the switching valve and connects the cylinder flow path and the main flow path; as well as A shuttle valve (32) having a first inlet (32a), a second inlet (32b) and an outlet (32c), wherein the first inlet is connected to a first portion (28a) of the detour flow path communicating with the main flow path, the outlet is connected to a second portion (28b) of the detour flow path communicating with the cylinder flow path, and the second inlet is connected to the pilot air adjustment unit. The pilot air adjustment unit includes a second throttle valve (31a) which limits the inflow speed of the pilot air into the switching valve, and the switching valve is switched from the first position to the second position by the increase of the pressure of the pilot air. When the pressure of the main flow path is higher than the pressure of the cylinder flow path, the shuttle valve closes the second inlet and connects the first inlet with the outlet, and when the pressure of the cylinder flow path is higher than the pressure of the main flow path, the shuttle valve closes the first inlet and connects the second inlet with the outlet.

3. The flow controller according to claim 2, characterized in that: The main flow path has a third throttle valve (25), and the bypass flow path bypasses the switching valve and the third throttle valve to connect the main flow path and the cylinder flow path.

4. The flow controller according to claim 2 or 3, characterized in that: A housing (40) is provided, the housing accommodating the switching valve, the pilot air adjustment unit, the first throttle valve, the bypass flow path and the shuttle valve. The housing has: a valve port (12a) in communication with the main flow path; an exhaust port communicating with the secondary flow path; and A cylinder port (12b) communicates with the cylinder flow path.

5. The flow controller according to claim 4, characterized in that: The switching valve has: a slide guide hole (42), the slide guide hole having a first communication groove (50) communicating with the valve port, a second communication groove (52) communicating with the first throttle valve, and a third communication groove (54) communicating with the cylinder port; A slide post (46), which is arranged in the slide post guide hole in a manner that allows it to slide in the axial direction, and is formed with a first closed wall (46c), a second closed wall (46d) and a recessed portion, wherein the first closed wall prevents the second communicating groove from communicating with the third communicating groove in the first position, and the second closed wall prevents the first communicating groove from communicating with the third communicating groove in the second position, and the recessed portion is formed between the first closed wall and the second closed wall, and the first communicating groove is communicated with the third communicating groove in the first position, and the second communicating groove is communicated with the third communicating groove in the second position; a return spring (26a) for applying force to the slide column toward the first position; as well as A piston portion (45) is configured to displace the spool toward the second position under the action of the pilot air flowing in from the cylinder port.

6. A driving device, the driving device (10) being characterized by comprising: a high-pressure air supply source (36) for supplying high-pressure air to the cylinder; an exhaust port that discharges exhaust air from the cylinder; a cylinder flow path, the cylinder flow path being in communication with a port of the cylinder; a main flow path for supplying and discharging air to the cylinder flow path; a secondary flow path, which is arranged in parallel with the primary flow path and has a first throttle valve, the first throttle valve throttling the flow rate of air to a smaller flow rate than that of the primary flow path; a switching valve connected to the cylinder flow path, the main flow path, and the secondary flow path, and switched to a first position in which the cylinder flow path is connected to the main flow path and a second position in which the cylinder flow path is connected to the secondary flow path; a flow controller having a pilot air adjustment section that guides a portion of the exhaust air as pilot air to the switching valve; as well as an action switching valve connected to the high-pressure air supply source, the exhaust port, and one end of the main flow path, and switchingly connecting the high-pressure air supply source or the exhaust port to the main flow path, The pilot air adjustment unit includes a second throttle valve that limits the inflow speed of the pilot air into the switching valve. When the exhaust air is discharged from the cylinder (14), the switching valve is located at the first position due to the elastic force of the return spring (26a), so that the exhaust air is discharged through the main flow path. When the pressure of the pilot air rises and becomes above the specified pressure as the piston (16) in the cylinder moves, the switching valve overcomes the elastic force of the return spring and switches from the first position to the second position, so that the exhaust air is discharged through the secondary flow path.

7. The driving device according to claim 6, characterized in that: The flow controller is connected to a top side port (76a) of the cylinder and a rod side port (78a) of the cylinder.

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