Cylinder Unit

Abstract

To provide a cylinder device having a valve mechanism of a simple configuration.SOLUTION: An output member (9) is movably inserted into a storage hole (4) of a housing (1). A support member (34) is movably inserted into a gap formed between the storage hole (4) and the output member (9) in a tightly sealed state, and the support member (34) forms a part of the housing (1). A valve mechanism (61) provided in the halfway of a flow passage (60) in the housing (1) closes and opens the flow passage (60). The valve mechanism (61) has a valve seat (65) formed on a peripheral wall of the storage hole (4) and a valve surface (66) formed on the support member (34).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a cylinder device equipped with a valve mechanism, and more particularly to a cylinder device equipped with a valve mechanism that detects when an object to be pressed has been clamped, in a cylinder device with a force-boosting mechanism. [Background technology]

[0002] A conventional cylinder device of this kind is described in Patent Document 1 (JP Patent Publication No. 2014-240117). This conventional technology is configured as follows. A cylinder hole is formed in the housing, and a piston is movably inserted into the cylinder hole. A flow path to which compressed air is supplied from a compressed air source is formed in the housing. A valve mechanism is provided in the middle of the flow path and on the upper end wall of the housing, and the valve mechanism closes and opens the flow path. A valve chamber of the valve mechanism communicates with the cylinder hole. A valve member is hermetically and movably inserted into the valve chamber, and a lower end of the valve member protrudes into the cylinder hole. A valve surface formed on the valve member can abut against a valve seat formed on a peripheral wall of the valve chamber. A valve closing spring is attached between the ceiling surface of the valve chamber and the upper surface of the valve body. When the piston moves the valve member to a predetermined position upward against the biasing force of the valve closing spring, the valve mechanism is opened. When the piston is separated downward from the valve member, the valve mechanism is closed by the biasing force of the valve closing spring. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-240117 A Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned conventional techniques have the following problems. In the above cylinder device, a valve member of a valve mechanism is provided in a valve chamber formed in a housing so as to protrude into a cylinder bore, and there was a problem in simplifying the structure of the valve mechanism. An object of the present invention is to provide a cylinder device equipped with a valve mechanism with a simple configuration. [Means for solving the problem]

[0005] In order to achieve the above object, the present invention provides a cylinder device configured as follows, for example, as shown in Figs. 1 and 2. A cylinder hole 2 formed in a housing 1 is connected to an accommodation hole 4 opened in a tip surface 3 of the housing 1. A first piston 5 for advancing and retreating is movably inserted into the cylinder hole 2. An output member 9 connected to the first piston 5 is provided protruding to the outside of the housing 1 through the accommodation hole 4. A second piston 33 for boosting force is movably inserted in a hermetically sealed state into a gap formed between an outer circumferential surface of the output member 9 and an inner circumferential surface of the cylinder hole 2. A support member 34 is movably inserted in a hermetically sealed state into a gap formed in the housing 1 or between an inner circumferential surface of the accommodation hole 4 and an outer circumferential surface of the output member 9. A boosting mechanism 47 provided in the cylinder hole 2 boosts the force of the pressure fluid applied to the second piston 33 and transmits it to the first piston 5 or the output member 9. An engagement member 49 constituting a part of the boosting mechanism 47 is movably inserted into a support hole 48 penetrating the support member 34. The engaging member 49 is capable of abutting against the outer circumferential surface of the output member 9 and a cam surface 51 formed on the output member 9, and is also capable of abutting against a pressing surface 53 formed on the second piston 33. Pressurized fluid is supplied to a flow passage 60 formed in the housing 1 or the support member 34. A valve mechanism 61 provided in the middle of the flow passage 60 closes and opens the flow passage 60. The valve mechanism 61 has a valve seat 65 formed on the peripheral wall of the accommodating hole 4, and a valve surface 66 formed on the support member 34. The reaction force of the force of the output member (9) pushing the object to be pressed moves the support member (34) via the output member (9) and the engagement member (49), causing the valve mechanism (61) to close or open the flow path (60).

[0006] The present invention provides the following advantages. In the above cylinder device, the valve member of the valve mechanism is formed by the support member that supports the engaging member of the booster mechanism, so that the valve mechanism can be simply configured.

[0007] The following configuration can be added to the above invention. The cam surface 51 is formed so as to be inclined with respect to the axis C of the cylinder bore 2. The pressing surface 53 is formed so as to be inclined with respect to the axis C. The angle that the cam surface 51 makes with respect to the axis C is configured so as to be larger than the angle that the pressing surface 53 makes with respect to the axis C. In this case, when the output member connected to the first piston presses the object to be pressed, the axial component of the force with which the second piston presses the engaging member becomes smaller than the axial component of the force with which the cam surface presses the engaging member due to the reaction force of the force of the output member pressing the object to be pressed. Therefore, when the output member presses the object to be pressed, the first piston presses the support member toward the base end side via the engaging ball against the force of the second piston pressing the engaging ball toward the tip side. At this time, the valve mechanism is closed or opened. Also, when the output member is not strongly pressing the object to be pressed, the pressing force according to the pressure of the pressure fluid in the cylinder hole or the second piston presses the support member toward the tip side via the engaging member. At this time, the valve mechanism is opened or closed. As a result, the valve mechanism detects in a timely manner that the object to be pressed is pressed by the output member. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic cross-sectional view showing a cylinder device in a released state according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view similar to FIG. 1, illustrating the operation of the cylinder device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to FIG. 1 and FIG. The housing 1 of the cylinder device with a force-boosting mechanism is fixed to a table T as a fixed base by a plurality of bolts (not shown). The housing 1 has an upper end wall (tip wall) 1a, a lower end wall (base end wall) 1b, and a body portion 1c.

[0010] A cylinder bore 2 is formed in the housing 1 in the vertical direction. The cylinder bore 2 is connected to the outside of the housing 1 via a receiving hole 4 that opens in an upper end surface 3 of the housing 1. A first piston 5 for advancing and retreating is inserted into the cylinder bore 2 so as to be movable in the vertical direction (the direction of the axis C of the cylinder bore). The first piston 5 has a piston body 6 formed in order from the bottom, and a piston rod 7 integrally provided protruding upward from the piston body 6. A cylindrical bore 8 is passed through the first piston 5 in the vertical direction.

[0011] A clamp rod 10 of an output member 9 is inserted into the cylindrical hole 8 of the first piston 5 in a sealed manner so as to be movable in the vertical direction. The clamp rod 10 protrudes to the outside of the housing 1 through the receiving hole 4. The diameter of the clamp rod 10 is set to be approximately the same as the diameter of the piston rod 7. An insertion part 11 protrudes from the lower part of the clamp rod 10. The insertion part 11 is formed to have a smaller diameter than the clamp rod 10. A small diameter part 12, a medium diameter part 13, and a large diameter part 14 are formed in this order below the insertion part 11. The cylindrical hole 8 of the first piston 5 has, in this order from the top, a guide hole 15, a small diameter hole 16, a medium diameter hole 17, and a large diameter hole 18. The insertion part 11 of the clamp rod 10 is inserted into the guide hole 15. The small diameter part 12, the medium diameter part 13, and the large diameter part 14 of the first piston 5 are inserted into the small diameter hole 16, the medium diameter hole 17, and the large diameter hole 18 of the cylindrical hole 8, respectively. An installation groove is formed in the circumferential direction on the outer circumferential wall of the insertion portion 11, and an O-ring 19 is installed in the installation groove as a sealing member. A compression spring (biasing means) 21 is installed between a step portion 20 formed between the guide hole 15 and the small diameter hole 16 and the lower surface of the insertion portion 11 of the clamp rod 10. The compression spring 21 biases the clamp rod 10 upward with respect to the piston rod 7. The lower end surface of the output member 9 is capable of abutting against the lower end wall 1b of the housing 1.

[0012] A locking portion 22 formed on the lower surface of the clamp rod 10 faces an engaging portion 23 formed on the upper surface of the piston rod 7 at a predetermined interval so as to be able to abut against it. One end of a link arm 24 is rotatably pin-connected to the tip of the clamp rod 10. A pivot portion 25 protrudes from the upper end wall 1a of the housing 1, and a base end of a link member 26 is rotatably pin-connected to the pivot portion 25, and a tip end of the link member 26 is rotatably connected to a longitudinal intermediate portion of the link arm 24. A pressing bolt 27 is screwed into the other end of the link arm 24, and the pressing bolt 27 is fixed to the link arm 24 by a nut 28. A pressing portion 29 is formed on the lower surface of the pressing bolt 27, and the pressing portion 29 is able to abut against the workpiece W.

[0013] A second piston 33 is inserted between the outer circumferential surface of the first piston 5 and the inner circumferential surface of the cylinder bore 2 in a hermetically sealed manner so as to be movable up and down.

[0014] A cylindrical support member 34 is inserted between the inner peripheral surface of the above-mentioned accommodation hole 4 and the outer peripheral surface of the clamp rod 10 in a hermetically sealed manner so as to be movable in the vertical direction. The support member 34 constitutes a part of the housing 1. The support member 34 has a large diameter portion 35 and a small diameter portion 36 formed in this order from the top. The large diameter portion 35 is inserted into the large diameter hole 37 of the accommodation hole 4 in a hermetically sealed manner so as to be movable in the vertical direction, and the small diameter portion 36 is inserted into the small diameter hole 38 of the accommodation hole 4. A step portion 39 is formed between the large diameter portion 35 and the small diameter portion 36. The step portion 39 of the support member 34 faces a step portion 40 formed between the large diameter hole 37 and the small diameter hole 38 of the accommodation hole 4 so as to be able to abut with a predetermined gap. A groove is formed in the circumferential direction in the middle of the height direction of the small diameter portion 36, and a retaining ring 41 is attached to the groove. The retaining ring 41 faces the peripheral wall of the accommodation hole 4 at a predetermined distance. This allows the support member 34 to move a predetermined distance, and the retaining ring 41 prevents the support member 34 from coming out of the receiving hole 4.

[0015] The cylinder bore 2 is divided into two chambers, an upper one and an lower one, by the first piston 5, the second piston 33, and the output member 9. A lock chamber 42 is formed between the lower end wall 1b of the first piston 5, the second piston 33, and the clamp rod 10, and a release chamber 43 is formed between the upper end wall 1a of the housing 1 and the first piston 5, the second piston 33, the output member 9, and the upper end wall 1a of the housing 1. A supply and discharge passage 44 for supplying and discharging compressed air (pressurized fluid) to and from the lock chamber 42 is formed in the upper end wall 1a and the body 1c of the housing 1, and another supply and discharge passage 45 for supplying and discharging compressed air (pressurized fluid) to and from the release chamber 43 is formed in the upper end wall 1a of the housing 1. A retaining spring 46 is attached to the lock chamber 42, and the retaining spring 46 urges the second piston 33 upward.

[0016] A boosting mechanism 47 is disposed in the release chamber 43. The boosting mechanism 47 is configured to convert the force of the compressed air in the lock chamber 42 pushing the second piston 33 upward (towards the release chamber 43) into a boosting force and transmit it to the first piston 5.

[0017] The boosting mechanism 47 is configured as follows. A plurality of support holes 48 are formed radially through the lower part of the cylindrical wall of the support member 34 at predetermined intervals in the circumferential direction. Engagement balls (engagement members) 49 are inserted into the support holes 48 so as to be movable in the radial direction.

[0018] A cam groove 50 is formed on the outer periphery of the piston rod 7 to correspond to the above-mentioned engagement ball 49. A cam surface 51 formed on the bottom wall of the cam groove 50 is formed so as to approach the axis as it extends downward. The engagement ball 49 is able to abut against the cam surface 51. In addition, a pressing surface 53 is formed in the upper half of the cylindrical hole 52 of the second piston 33 so as to approach the axis as it extends downward. The engagement ball 49 is able to abut against the pressing surface 53.

[0019] A pressing portion 54 is formed in the cylindrical hole 52 above the pressing surface 53 so as to approach the axis as it moves downward. As a result, when the booster drive of the booster mechanism 47 starts, the pressing portion 54 presses the engagement ball 49 radially inward. Also, during the lock drive process from the start of the lock drive of the cylinder device to just before the start of the booster drive of the booster mechanism 47, the pressing portion 54 presses the engagement ball 49 radially inward toward a guide surface 55 formed on the outer circumferential surface of the piston rod 7. The force with which the pressing portion 54 presses the engagement ball 49 radially inward is set to be smaller than the force with which the pressing surface 53 presses the engagement ball 49 radially inward.

[0020] A valve mechanism 61 for detecting when the clamp device starts boosting drive is provided in the housing 1, and the valve mechanism 61 is configured as follows.

[0021] A flow path 60 for compressed air is formed in the housing 1. A valve mechanism 61 is provided in the middle of the flow path 60, and the valve mechanism 61 closes and opens the flow path 60. A supply port (not shown) as a part of the flow path 60 is opened on the back surface of the flange portion 1d of the housing 1. A passage from a supply source of compressed air for detection (not shown) is connected to the supply port, and a pressure switch (or pressure sensor) (not shown) is provided in the middle of the passage. One end of an inlet path 63 constituting a part of the flow path 60 is communicated with the supply port, and the other end of the inlet path 63 is opened to the inner circumferential surface of the small diameter hole 38 of the accommodation hole 4. A valve chamber 64 of the valve mechanism 61 is defined and formed by the inner circumferential surface of the large diameter hole 37 of the accommodation hole 4, the outer circumferential surface of the small diameter portion 36 of the support member 34, the step portion 39 of the support member 34, the step portion 40 of the accommodation hole 4, and the inner circumferential surface of the small diameter hole 38 of the accommodation hole 4. The valve mechanism 61 has a valve seat 65 formed in the stepped portion 40 of the accommodating hole 4 and a valve surface 66 formed in the stepped portion 39 of the support member 34. One end of an outlet passage 67, which is a part of the flow path 60, opens into the inner circumferential surface of the large diameter hole 37 of the accommodating hole 4. The other end of the outlet passage 67 is discharged to the outside from a discharge port (not shown) formed in the housing 1.

[0022] As shown in Figs. 1 and 2, the cylinder device shown in the above embodiment operates as follows. 1, compressed air is discharged from the lock chamber 42 and supplied to the release chamber 43. As a result, the compressed air in the release chamber 43 lowers the first piston 5 and the second piston 33 to their lowest positions. At this time, the compressed air in the release chamber 43 pushes the support member 34 upward, and the retaining ring 41 is received by the peripheral wall of the accommodation hole 4. As a result, the support member 34 is moved to the upper limit position. As a result, the valve surface 66 of the support member 34 is separated upward from the valve seat 65 on the peripheral wall of the accommodation hole 4, and the valve mechanism 61 is opened. In the above-mentioned released state, a workpiece W is carried in above the clamp rod 10 and placed on the table T.

[0023] When the cylinder device is locked from the release state of FIG. 1 to the lock state of FIG. 2, compressed air is discharged from the release chamber 43 and supplied to the lock chamber 42. Then, the pressure of the compressed air in the release chamber 43 decreases, and the support member 34 tries to move down due to its own weight, but the support member 34 is maintained at the upper limit position due to the sealing resistance of the sealing member of the support member 34. Alternatively, the pressure of the compressed air in the lock chamber 42 and the urging force of the retaining spring 46 move the second piston 33 upward by a small mechanical clearance, and the second piston 33 pushes the support member 34 upward via the engagement ball 49 to maintain it at the upper limit position. As a result, the valve mechanism 61 is also maintained in the open state. At this time, the engagement ball 49 is received by the guide surface 55 of the piston rod 7, and the radial inward movement is prevented, and the second piston 33 is prevented from rising beyond the mechanical clearance. Next, the first piston 5 rises with a low load, leaving the second piston 33 at the lower position. Subsequently, the first piston 5 raises the clamp rod 10 via the compression spring 21. This causes the pressing portion 29 of the clamp rod 10 to come into contact with the upper surface of the workpiece W. As a result, the output member 9 is received by the workpiece W via the link arm 24, but the first piston 5 is raised against the biasing force of the compression spring 21.

[0024] Then, the first piston 5 is moved upward, and the cam surface 51 of the first piston 5 rises to the height position of the engagement ball 49. Then, the engagement ball 49 is allowed to move radially inward. Next, the resultant force of the pressing force corresponding to the pressure of the compressed air in the lock chamber 42 and the urging force of the holding spring 46 moves the engagement ball 49 radially inward via the pressing portion 54 of the second piston 33, and the engagement ball 49 presses the cam surface 51. This brings the boosting mechanism 61 into a state in which it has started boosting. Next, the second piston 33 moves the first piston 5 upward against the urging force of the compression spring 21 via the pressing surface 53, the engagement ball 49, and the cam surface 51 (the state immediately before locking is when the engagement portion 23 of the piston rod 7 is not in contact with the locking portion 22 of the clamp rod 10). 2, the engaging portion 23 of the piston rod 7 comes into contact with the locking portion 22 of the clamp rod 10 (the first piston 5 and the output member 9 are connected). This causes the second piston 33 to strongly press the workpiece W from above toward the table W via the first piston 5, the engaging ball 49, the output member 9, and the link arm 24. As a result, the cylinder device is switched from the released state to the locked state.

[0025] Here, the angle β at which the pressing surface 53 is inclined relative to the axis C of the cylinder bore 2 is set to be smaller than the angle α at which the cam surface 51 is inclined relative to the axis C of the cylinder bore 2 (β<α). For this reason, when the cylinder device is switched from the released state to the locked state, the upward (direction of the axis C of the cylinder bore 2) component of the force with which the second piston 33 presses the engagement ball 49 is smaller than the downward component of the force with which the reaction force of the link arm 24 pressing the workpiece W presses the engagement ball 49 via the cam surface 51 of the first piston 5, etc. As a result, when the cylinder device is switched from the immediately before locked state to the locked state (when the engagement portion 23 of the piston rod 7 abuts against the locking portion 22 of the clamp rod 10), the first piston 5 moves the support member 34 to the lower limit position via the engagement ball 49. The valve surface 66 of the support member 34 is received by the valve seat 65 of the accommodation hole 8, and the valve mechanism 61 is closed. Therefore, the compressed air in the inlet passage 63 passes through the valve chamber 64, the opening gap between the valve face 66 and the valve seat 65, and the outlet passage 67 and is discharged to the outside of the housing 1. This increases the pressure of the compressed air in the inlet passage 63, and this increase in pressure is detected by a pressure switch (not shown). As a result, the valve mechanism 61 detects that the output member 9 has pressed the workpiece W via the link arm 24.

[0026] When the cylinder device is switched from the locked state of FIG. 2 to the released state of FIG. 1, compressed air is discharged from the lock chamber 42 and supplied to the release chamber 43 in the locked state of FIG. 2. Then, the compressed air in the release chamber 43 moves the second piston 33 downward, and the engagement ball 49 is allowed to move radially outward. At this time, the engagement ball 49 can be separated from the cam surface 51, so that the cam surface 51 stops pushing the support member 34 downward via the engagement ball 49. Then, the compressed air in the release chamber 43 moves the support member 34 upward. Therefore, the valve surface 66 of the valve mechanism 61 is separated from the valve seat 65, and the valve mechanism 61 is opened. Therefore, the compressed air in the inlet passage 63 is discharged to the outside of the housing 1 through the valve chamber 64, the opening gap between the valve surface 66 and the valve seat 65, and the outlet passage 67. Next, the compressed air in the release chamber 43 moves the first piston 5 downward, and the cam surface 51 of the second piston 33 pushes the engagement ball 49 radially outward. Next, the guide surface 55 of the piston rod 7 contacts the engagement ball 49, and the guide surface 55 of the piston rod 7 prevents the engagement ball 49 from moving radially inward. Subsequently, the second piston 33 is received from below by the lower end wall 1b. After that, the first piston 5 is further lowered relative to the second piston 33 whose movement in the vertical direction is prevented by the engagement ball 49 and the guide surface 55. Then, the first piston 5 pushes down the large diameter portion 14 of the output member 9. Then, the first piston 5 is received by the lower end wall 1b of the housing 1 via the large diameter portion 14 of the output member 9. This switches the cylinder device from the locked state to the released state.

[0027] The above embodiment has the following advantages. In the cylinder device of the present invention, the support member 34 that supports the engaging ball 49 of the booster mechanism 47 is configured as the valve member of the valve mechanism 61, so there is no need to provide a separate valve member as in the prior art cylinder device. Therefore, the cylinder device can be simply configured.

[0028] In addition, when the piston is moved to a predetermined position, the valve mechanism provided in the conventional cylinder device described above opens when the second piston pushes up the valve member of the valve mechanism. In other words, regardless of whether the output member presses the workpiece or not, the force boosting mechanism is assumed to have been activated by detecting the operation of the piston, and it is assumed that the output member has pressed the workpiece based on the detection result. In contrast, the valve mechanism 61 provided in the cylinder device of the above embodiment maintains an open state from the release state to the state immediately before locking, and closes when the link arm 24 is in a locked state in which it strongly presses the workpiece through the output member 9. Therefore, after the boost mechanism 47 is activated, the valve mechanism 61 detects that the cylinder device has pressed the workpiece W. In addition, when the boost mechanism 47 is activated, the support member 34 supporting the engagement ball 49 of the boost mechanism 47 moves slightly inside the housing 1. The movement of the support member 34 is visually confirmed by the worker from outside the housing 1, so that the worker knows that the boost mechanism has been activated. As a result, in the cylinder device of this embodiment, instead of guessing as in the conventional cylinder device, it is possible to actually and timely detect that the tip of the link arm 24 has pressed the workpiece, and the worker can visually confirm the operating state of the boost mechanism inside the device.

[0029] In the above embodiment, the locked state is a state in which the compressed air in the lock chamber 42 presses the pressing portion 29 of the pressing bolt 27 against the workpiece W via the first piston 5, the output member 9, and the link arm 24, and the engagement portion 23 of the first piston 5 abuts against the locking portion 22 of the output member 9. In this state, a pressing force equivalent to the pressure of the compressed air in the lock chamber 42 acts strongly on the workpiece W via the first piston 5, the output member 9, etc. In addition, the state immediately before locking refers to a state in which the boost mechanism is operating, but the engagement portion 23 of the first piston 5 is not abutting against the locking portion 22 of the output member 9, and a pressing force equivalent to the pressure of the compressed air in the lock chamber 42 acts on the workpiece W via the first piston 5, the compression spring 21, the output member 9, etc., so that a sufficient pressing force is not acting.

[0030] Here, in this embodiment, instead of the first piston 5 and the output member 9 being configured by separate members, the first piston 5 and the output member 9 may be formed integrally. In this case, when the first piston 5 abuts against the workpiece W via the output member 9 and the link arm 24 or the like, the state is switched from the released state to the locked state. At this time, the reaction force of the force with which the link arm 24 presses the workpiece W moves the support member 34 downward via the cam surface 51 and the engagement ball 49. This causes the valve mechanism 61 to close.

[0031] The above embodiments can be modified as follows. The installation posture of the cylinder device may be upside down from the posture exemplified above, or may be installed sideways or at an angle. The above pressure fluid may be other gases or liquids such as pressure oil instead of compressed air as exemplified above. Instead of mounting the retaining spring 46 in the lock chamber 42, a release spring may be mounted in the release chamber 43. Also, a single-acting cylinder may be used instead of the double-acting cylinder. The first piston 5 is not limited to being constituted by the piston body 6 and the piston rod 7, and may omit the piston rod 7. In this case, the cam groove 50 and the cam surface 51 are formed on the outer circumferential surface of the piston body 6. The output member 9 may be integrally connected to the first piston 5 instead of being inserted into the cylindrical hole 8 of the first piston 5 so as to be vertically movable. In this case, the compression spring 21 and the like are omitted. The number of engagement members 49 is preferably three or four, but may be two or five or more. The engagement members are not limited to the engagement balls 49 shown as an example, and may be members of other shapes, such as cylindrical rollers. Instead of the above-mentioned cylindrical support member 34 being movably inserted in a hermetically sealed state between the inner peripheral surface of the accommodation hole 4 and the outer peripheral surface of the output member 9, a rod-shaped support member 34 such as a cylinder or a rectangular column may be hermetically inserted in a through hole formed in the upper end wall 1a of the housing 1 so as to be axially movably inserted in a hermetically sealed state. In this case, the support member 34 has a large diameter portion 35 and a small diameter portion 36, and the large diameter portion 35 and the small diameter portion 36 are inserted into the large diameter hole and the small diameter hole of the through hole. The support holes 48 into which the engaging members 49 are inserted may penetrate the peripheral wall of the support member 34 in an oblique direction instead of penetrating horizontally. The biasing means may be an elastic member such as rubber or resin, or a gas spring, instead of the compression spring 21 illustrated. Instead of providing the inlet passage 63 and / or the outlet passage 67 of the flow passage 60 in the housing 1, they may be provided in the support member 34, or may be provided across the housing 1 and the support member 34. The outlet passage 67 may be configured by a gap formed between the inner peripheral wall of the accommodating hole 4 and the outer peripheral wall of the support member 34. In this case, the sealing member provided between the inner peripheral wall of the accommodating hole 4 and the outer peripheral wall of the support member 34 (closer to the upper end surface 3 of the housing 1) is omitted. The valve mechanism 61 may be configured to be closed when the support member 34 rises and open when the support member 34 falls, instead of being opened when the support member 34 rises and closed when the support member 34 falls. In this case, the accommodation hole 4 has a small diameter hole and a large diameter hole formed in that order from the top. The support member 34 has a small diameter portion and a large diameter portion formed in that order from the top. A valve seat 65 is formed in the step portion 40 of the accommodation hole 4, and a valve surface 66 is formed in the step portion 39 of the support member 34. Of course, various other modifications can be made within the scope of what a person skilled in the art can imagine. [Explanation of symbols]

[0032] 1: housing, 3: upper end surface (tip surface), 4: accommodation hole, 2: cylinder hole, 5: first piston, 9: output member, 33: second piston, 34: support member, 48: support hole, 49: engagement member, 51: cam surface, 53: pressing surface, 60: flow path, 61: valve mechanism, 65: valve seat, 66: valve surface.

Claims

1. A cylinder hole (2) formed in a housing (1) and connected to a receiving hole (4) that opens into a tip end surface (3) of the housing (1); A first piston (5) for moving forward and backward and movably inserted into the cylinder hole (2); an output member (9) connected to the first piston (5) and projecting to the outside of the housing (1) through the receiving hole (4); a second piston (33) for boosting force, which is movably inserted in a hermetically sealed state into a gap formed between an outer peripheral surface of the output member (9) and an inner peripheral surface of the cylinder hole (2); a support member (34) that is movably inserted in a hermetically sealed manner into the housing (1) or into a gap formed between an inner peripheral surface of the receiving hole (4) and an outer peripheral surface of the output member (9); a boosting mechanism (47) provided in the cylinder bore (2) for boosting the force of the pressure fluid applied to the second piston (33) and transmitting the force to the first piston (5); an engaging member (49) that constitutes a part of the force multiplying mechanism (47) and is movably inserted into a support hole (48) that penetrates the support member (34), the engaging member (49) being capable of abutting against an outer circumferential surface of the output member (9) and a cam surface (51) formed on the output member (9) and being capable of abutting against a pressing surface (53) formed on the second piston (33); a flow passage (60) to which a pressure fluid is supplied and which is formed in the housing (1) or the support member (34); a valve mechanism (61) provided in a middle portion of the flow path (60) and configured to close and open the flow path (60), the valve mechanism (61) having a valve seat (65) formed on a peripheral wall of the accommodation hole (4) and a valve surface (66) formed on the support member (34), A reaction force of a force of the output member (9) pushing a pressing object moves the support member (34) via the output member (9) and the engagement member (49), whereby the valve mechanism (61) closes or opens the flow path (60). A cylinder device characterized in that:

2. The cylinder device according to claim 1, The cam surface (51) is formed so as to be inclined with respect to the axis (C) of the cylinder hole (2), The pressing surface (53) is formed so as to be inclined with respect to the axis (C), A cylinder device characterized in that the angle that the cam surface (51) makes with respect to the axis (C) is larger than the angle that the pressing surface (53) makes with respect to the axis (C).

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