JP2016006353A - Fluid pressure cylinder and clamp device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid pressure cylinder and a clamp device capable of certainly detecting that an output member reaches a predetermined position through pressure changes of air pressure in a clamp body, having excellent reliability and durability, and being downsized.SOLUTION: A fluid pressure cylinder includes: air passages 21 and 22 formed in a cylinder body 10 of a hydraulic cylinder 3, supplied pressurized air at one end portions, and communicating to the outside at the other end portions; and open/close valve mechanisms 30 and 50 capable of opening/closing the air passages. The open/close valve mechanism is equipped with a valve body installed so as to move forward/backward, and projecting out to a hydraulic chamber at a tip end portion; a valve seat on which the valve body can abut; a hydraulic pressure introducing chamber for holding the valve body in a state moving forward to an output member 4 side by the hydraulic pressure of the hydraulic chambers 14 and 15; and a hydraulic pressure introducing passage communicating with the hydraulic chamber and the hydraulic pressure introducing chamber. When the output member reaches a predetermined position, the valve body is moved by the output member to switch an opening/closing state of the open/close valve mechanism, thereby detecting that the output member reaches the predetermined position, through air pressure in the air passages.

Description

  In the present invention, when the output member reaches a predetermined position such as a forward limit position or a reverse limit position, the air passage in the cylinder body is switched by the on-off valve mechanism in conjunction with the operation of the output member. The present invention relates to a fluid pressure cylinder and a clamp device that can detect the position of the output member through a change in pressure.

  2. Description of the Related Art Conventionally, a fluid pressure cylinder employed in a clamping device that clamps a clamping object such as a workpiece to be machined includes a cylinder body, an output member that is mounted on the cylinder body so as to freely move back and forth, and the output member. A fluid chamber or the like is provided for driving on at least one of the advance side and the entry side.

  By the way, various rod position detection techniques for detecting predetermined positions (forward limit position, reverse limit position, intermediate position, etc.) in the axial direction of the output member of the fluid pressure cylinder have been put into practical use.

  For example, the clamping device of Patent Document 1 includes a pressure sensor that detects a fluid pressure supplied to a fluid pressure cylinder, and a raised position of a detected portion at a lower end portion of an operation rod that protrudes outside from a piston member of the fluid pressure cylinder. The position of the piston rod is detected by two position sensors that detect the lowered position.

  In the clamp device disclosed in Patent Document 2, a mechanism for opening and closing the air passage is provided in conjunction with the lifting and lowering operation of the output rod of the fluid pressure cylinder so that the ascending position and the descending position of the output rod can be detected.

  In the clamp apparatus of patent document 3, the workpiece cradle which receives a clamp target object is provided independently. The work cradle includes a pad member in which an air ejection port is formed, and an outer cylinder member that elastically supports the pad member on the clamping object side. When the pad member is in the projecting position, pressurized air is ejected from the air ejection port, and when the clamping device is driven to clamp and the pad member is pressed and retracted by the object to be clamped, the air ejection port is formed in the outer cylinder member. It is detected that the pressure of the pressurized air has increased and the clamped state has been reached.

JP 2001-87991 A JP 2003-305626 A JP 2009-125821 A

  In the clamp device disclosed in Patent Document 1, an operation rod is protruded outside from a piston member of a fluid pressure cylinder, and an ascending position and a descending position of a detected portion provided at a lower end portion of the operation rod are detected by two position sensors. Since a detection space for moving the detected portion and installing the position sensor is required on the lower side of the fluid pressure cylinder, there is a problem that the clamping device (that is, the fluid pressure cylinder) is increased in size.

  In the clamp device disclosed in Patent Document 2, a mechanism for detecting the raised position and the lowered position of the output rod is configured outside the clamp body. Therefore, similarly to the clamp device disclosed in Patent Document 1, a detection space is required outside the clamp body, and therefore the clamp device cannot be configured compactly. In addition, since the detector that opens and closes the air passage is slidably moved with respect to the detection hole, the performance of closing the air passage may deteriorate when used for a long period of time.

  Since the air ejection port of the work cradle of the clamping device of Patent Document 3 is open in the vicinity of the clamping device and the object to be clamped in the unclamped state, machining chips and coolant (cutting fluid) are generated. There is a risk of entering the air outlet and blocking it.

  An object of the present invention is to provide a fluid pressure cylinder and a clamp device that can reliably detect that the output member has reached a predetermined position through a change in the air pressure of the air passage in the cylinder body and can be downsized. That is, providing a fluid pressure cylinder and a clamp device that can improve the reliability and durability of detecting a predetermined position of the output member.

The fluid pressure cylinder according to claim 1 includes a cylinder main body, an output member equipped to be able to advance and retreat in the cylinder main body, and a fluid chamber for driving the output member to at least one of the advance side and the retreat side. The fluid pressure cylinder includes an air passage formed in the cylinder body and supplied with pressurized air at one end and communicated with the outside at the other end, and an on-off valve mechanism capable of opening and closing the air passage. The valve mechanism includes a valve body that is movably mounted in a mounting hole formed in the cylinder body and has a tip projecting into the fluid chamber, a valve seat that can contact the valve body, and a fluid pressure in the fluid chamber. A fluid pressure introducing chamber that holds the valve body in a state of being advanced to the output member side, and a fluid pressure introducing passage that communicates the fluid chamber and the fluid pressure introducing chamber.
When the output member reaches a predetermined position, the valve body is moved by the output member to switch the open / close state of the on-off valve mechanism, and the output member is moved to the predetermined position via the air pressure of the air passage. It is characterized in that it can detect that the position has been reached.

  The fluid pressure cylinder according to a second aspect is the invention according to the first aspect, wherein the on-off valve mechanism maintains a valve open state in which the valve body is separated from the valve seat in a state where the fluid pressure is supplied to the fluid chamber. When the fluid pressure in the fluid chamber is switched to the drain pressure and the output member reaches a predetermined position, the on-off valve mechanism is switched to a closed state in which the valve body is in contact with the valve seat. It is characterized by.

  The fluid pressure cylinder according to claim 3 is the invention according to claim 1, wherein when the fluid pressure is supplied to the fluid chamber, the on-off valve mechanism maintains the valve closed state in which the valve body is in contact with the valve seat. When the fluid pressure in the fluid chamber is switched to the drain pressure and the output member reaches a predetermined position, the on-off valve mechanism is switched to an open state in which the valve body is separated from the valve seat. It is characterized by.

  According to a fourth aspect of the present invention, there is provided the fluid pressure cylinder according to the second aspect of the present invention, wherein the on-off valve mechanism is inserted and screwed into the mounting hole formed in the cylinder body and the valve body is inserted so as to be able to advance and retract. The valve member is formed at the output member side end portion of the cap member, and the fluid pressure introducing chamber is formed between the cap member and the valve body.

  According to a fifth aspect of the present invention, there is provided the fluid pressure cylinder according to the fourth aspect of the invention, wherein the valve body includes a valve body main body, and a movable valve body that is externally fitted to the valve body main body and can approach and separate from the valve seat. And a seal member is provided between the valve body main body and the movable valve body.

  The fluid pressure cylinder according to claim 6 is characterized in that, in the invention according to claim 1, the fluid pressure introduction path of the on-off valve mechanism is formed in a penetrating manner in the valve body.

  According to a seventh aspect of the present invention, the fluid pressure cylinder according to the first aspect of the invention is characterized in that the on-off valve mechanism includes an elastic member that elastically urges the valve body toward the output member.

  The fluid pressure cylinder according to an eighth aspect is the invention according to the first aspect, wherein the predetermined position is any one of an upper limit position, an operation intermediate position, and a lower limit position of the output member.

  According to a ninth aspect of the present invention, there is provided a clamp device including the clamp rod made of the output member, wherein the clamp rod is driven by the fluid pressure cylinder according to the eighth aspect.

  According to the fluid pressure cylinder of the first aspect, the on-off valve mechanism for opening and closing the air passage in the cylinder body is provided, and the on-off valve mechanism includes a valve body, a valve seat, a fluid pressure introduction chamber, and a fluid pressure introduction path. Since the on-off valve mechanism can be incorporated into the cylinder body by incorporating the valve body into the mounting hole formed in the clamp body, the fluid pressure cylinder can be reduced in size.

  The fluid pressure of the fluid chamber of the front fluid pressure cylinder can be introduced into the fluid pressure introduction chamber of the on-off valve mechanism via the fluid pressure introduction path, and the fluid in the fluid chamber is in a state where the output member does not reach the predetermined position. The valve body can be held in a state of projecting toward the fluid chamber using the pressure, and the open / close state of the open / close valve mechanism can be maintained. Since the valve body is biased by utilizing the fluid pressure in the fluid chamber, it is advantageous in terms of reliability and durability.

  When the output member reaches a predetermined position, the valve body is moved by the output member so that the open / close state of the open / close valve mechanism is switched reliably, so that the predetermined position of the output member is reliably set via the air pressure of the air passage. It can be detected.

  According to the fluid pressure cylinder of the second aspect, it is possible to detect that the output member has reached the predetermined position via the air pressure changed from the state where the air passage is communicated to the state where it is shut off.

  According to the fluid pressure cylinder of the third aspect, it is possible to detect that the output member has reached the predetermined position via the air pressure changed from the state where the air passage is blocked to the state where it is communicated.

  According to the fluid pressure cylinder of the fourth aspect, the on-off valve mechanism can be incorporated into the cylinder body in a compact manner.

  According to the fluid pressure cylinder of claim 5, since the friction force is generated between the main body portion and the valve member by the seal member when the main body portion moves, the valve member is moved following the movement of the main body portion. Can be made.

  According to the fluid pressure cylinder of the sixth aspect, it is not necessary to form a fluid pressure introduction path in the cylinder body, and the on-off valve mechanism can be configured compactly.

  According to the fluid pressure cylinder of the seventh aspect, when the fluid pressure in the fluid chamber is switched to the drain pressure, the open / close state of the open / close valve mechanism can be maintained until the output member reaches a predetermined position.

  According to the fluid pressure cylinder of the eighth aspect, it is possible to reliably detect that the output member has reached any one of the upper limit position, the operation halfway position, and the lower limit position.

  According to the clamp device of the ninth aspect, the same effect as that of the first aspect can be obtained in the clamp device of the type in which the clamp rod is driven by the fluid pressure cylinder.

It is sectional drawing of the clamp apparatus (unclamped state) of Example 1 of this invention. It is an enlarged view of the a part of FIG. It is an enlarged view of the b section of FIG. It is sectional drawing of a clamp apparatus (position just before a raise limit). It is the VV sectional view taken on the line of FIG. FIG. 6 is a sectional view taken along line VI-VI in FIG. 5. It is an enlarged view of the c section of FIG. It is principal part sectional drawing of the clamp apparatus (clamp state) of Example 1. FIG. It is an enlarged view of the d section of FIG. It is an enlarged view of the e section of FIG. It is sectional drawing of the 2nd on-off valve mechanism (valve open state) of Example 2. FIG. It is sectional drawing of the on-off valve mechanism (valve closed state) of FIG. It is sectional drawing of the cylinder main body principal part of Example 3, and a 2nd on-off valve mechanism (valve open state). It is sectional drawing of the cylinder main part of Example 3, and an on-off valve mechanism (valve closed state). It is sectional drawing of the cylinder main part of Example 4, and an on-off valve mechanism (valve open state). It is sectional drawing of the cylinder main part of Example 4, and an on-off valve mechanism (valve closing state). It is sectional drawing of the clamp apparatus (unclamped state) of Example 5. FIG. It is an enlarged view of the f section of FIG. It is an enlarged view of the g section of FIG. It is sectional drawing of the clamp apparatus (position just before a raise limit) of Example 5. FIG. It is an enlarged view of the h section of FIG. It is sectional drawing of the clamp apparatus of Example 5 (clamp state). It is an enlarged view of the i section of FIG. It is an enlarged view of the j section of FIG. It is sectional drawing of the clamp apparatus (unclamped state) of Example 6. FIG. It is an enlarged view of the k section of FIG. FIG. 27 is a view corresponding to FIG. 26 in a clamped state. It is sectional drawing of the clamp apparatus (unclamped state) of Example 7. It is sectional drawing of the clamp apparatus (unclamped state) of Example 7. It is an enlarged view of the m section of FIG. It is sectional drawing of the clamp apparatus (clamp state) of Example 7. FIG. 32 is an enlarged view of a portion n in FIG. 31. It is sectional drawing of the clamp apparatus (unclamped state) of Example 8. FIG. It is an enlarged view of the p section of FIG. It is sectional drawing of the clamp apparatus (clamp state) of Example 8. FIG. 36 is an enlarged view of a part q in FIG. 35.

Hereinafter, modes for carrying out the present invention will be described based on examples.
This embodiment is an example in which the present invention is applied to a clamp device configured to drive an output member (clamp rod) by a hydraulic cylinder as a fluid pressure cylinder.

First, the overall configuration of the clamping device will be described.
As shown in FIGS. 1-10, the clamp apparatus 1 is assembled | attached to the base member 2, such as a pallet, so that it may protrude upwards. The clamping device 1 fixes a clamping object such as a workpiece to the fixing surface 2a of the base member 2 so as to be unfixable. Hereinafter, “hydraulic pressure” (fluid pressure) means compressed oil.

  The clamping device 1 is formed in a hydraulic cylinder 3 (fluid pressure cylinder) in a vertical posture, an output member 4, and a cylinder body 10 of the hydraulic cylinder 3, and is supplied with pressurized air at one end and communicates with the other end at the other end. The first and second air passages 21 and 22 and the first and second on-off valve mechanisms 30 and 50 capable of opening and closing the first and second air passages 21 and 22, respectively.

  The first on-off valve mechanism 30 is for detecting that the output member 4 is at the ascent limit position via the air pressure in the first air passage 21. The second on-off valve mechanism 50 is for detecting that the output member 4 is at the lower limit position via the air pressure in the second air passage 22. The rising limit position of the output member 4 corresponds to “a predetermined position of the output member”. Similarly, the lower limit position of the output member 4 corresponds to “another predetermined position of the output member”.

Next, the cylinder body 10 will be described.
As shown in FIGS. 1, 4, 6, and 8, the cylinder body 10 is fixed to the cylinder member 11, the upper end wall member 12 fixed to the upper end of the cylinder member 11, and the lower end of the cylinder member 11. A lower end wall member 13 and the like are provided. The base member 2 is formed with an open upper end mounting hole 2b, and the cylinder member 11 and the lower end wall member 13 of the cylinder body 10 are fitted in the mounting hole. A part of the lower end surface of the upper end wall member 12 is in contact with the fixing surface 2a, and the upper end wall member 12 is fixed to the base member 2 by a plurality of (for example, four) bolts that pass through the plurality of bolt holes 12a.

  The upper end wall member 12 is formed with an insertion hole through which the output member 4 is inserted. The insertion hole has a lower first insertion hole 12b and an upper second insertion hole 12c. The second insertion hole 12c The diameter is slightly smaller than that of the first insertion hole 12b. An annular seal mounting recess 12d is formed at the upper end portion of the second insertion hole 12c. The cylinder member 11 is formed with a cylinder hole 11a that is continuous with the lower end of the first insertion hole 12b and has a larger diameter than the first insertion hole 12b. A cylindrical portion 12e at the lower end of the upper end wall member 12 is fitted into the upper end of the cylinder hole 11a, and a protruding portion 13a at the upper end of the lower end wall member 13 is fitted into the lower end of the cylinder hole 11a. 12 and the lower end wall member 13 are respectively fixed to the cylinder member 11 by a plurality of (for example, six) bolts.

Next, the output member 4 will be described.
As shown in FIGS. 1, 4, 6, and 8, the output member 4 is a clamp rod (that is, piston rod member 4a) of the clamp device 1. One end portion of the clamp arm 4b in a horizontal posture is fixed to the upper end portion of the output member 4. The piston rod member 4a is mounted on the cylinder body 10 so as to be able to advance and retract in the axial direction. The piston rod member 4a has a piston rod portion 4c and a piston portion 4p fixed to the lower end portion thereof.

  The piston rod portion 4c is inserted into the second insertion hole 12c through a small-diameter rod portion 4d that is oil-tightly slidably inserted and a lower end of the small-diameter rod portion 4d, with a small annular gap provided in the first insertion hole 12b. And a possible large diameter rod portion 4e. The piston portion 4p is slidably mounted in the cylinder hole 11a in an oil-tight manner. A part of the small diameter rod portion 4d protrudes upward from the cylinder body 10. The clamp arm 4b is fixed to the upper end portion of the small diameter rod portion 4d with a bolt. As the clamp arm 4b, a clamp arm having a size corresponding to the thickness of the object to be clamped (particularly, a thickness in the vertical direction) is used.

  When the piston rod member 4a reaches the upper limit position (unclamp position) (see FIG. 1), the piston portion 4p contacts the lower surface of the upper end wall member 12, and the large-diameter rod portion 4e is inserted into the first insertion hole 12b. It becomes a state. When the piston rod member 4a reaches the lower limit position (clamp position) (see FIG. 8), the piston portion 4p comes into contact with the upper surface of the lower end wall member 13. The cylinder body 10 is provided with seal members 10a to 10c for oil-tight sealing, and a seal member 4s is mounted on the outer peripheral portion of the piston portion 4p. An annular dust seal 12f that contacts the outer peripheral surface of the small-diameter rod portion 4d is attached to the seal mounting recess 12d.

  In the cylinder body 10, an annular clamp oil chamber 14 on the upper side of the piston portion 4p and an unclamp oil chamber 15 on the lower side of the piston portion 4p are provided, and the clamp oil chamber 14 is placed in the first insertion hole 12b. It has the cylinder part 14a which is a cylindrical oil chamber part extended.

  The clamping oil chamber 14 and the unclamping oil chamber 15 are connected to the hydraulic pressure supply source 5 through an oil passage (not shown). When hydraulic pressure is supplied to the clamp oil chamber 14 and the hydraulic pressure is released from the unclamp oil chamber 15, the piston rod member 4a is driven to be clamped in the downward direction, and the clamp arm 4b fixes the object to be clamped to the base member 2 at the lower limit position. It will be in the clamped state pressed against the surface 2a. On the contrary, when the hydraulic pressure is supplied to the unclamping oil chamber 15 and the hydraulic pressure is released from the clamping oil chamber 14, the piston rod member 4a is unclamped in the upward direction.

Next, the first air passage 21 will be described.
As shown in FIGS. 1, 4, 6, and 8, the first air passage 21 is connected to the upstream air passage 21 a and the upstream air passage 21 a through a first on-off valve mechanism 30 described later. And a downstream air passage 21b. The upstream end of the upstream air passage 21 a is connected to a first air supply path 21 s formed in the base member 2, and the downstream end of the downstream air passage 21 b is connected to a first air discharge path 21 e formed in the base member 2. Has been.

  The upstream air passage 21 a includes a vertical air passage formed inside the cylinder member 11 and the upper end wall member 12, and a horizontal air passage formed inside the upper end wall member 12. The downstream air passage 21 b is formed inside the cylinder member 11 and the upper end wall member 12.

Next, the second air passage 22 will be described.
As shown in FIGS. 1, 4, 6 and 8, the upstream end of the second air passage 22 is connected to a second air supply passage 22 s formed in the base member 2, and the downstream end of the second air passage 22. Is connected to a second air discharge passage 22e formed in the base member 2 through the mounting hole 2b. A second on-off valve mechanism 50 is connected to the downstream end of the second air passage 22. The second air passage 22 includes a vertical air passage formed inside the cylinder member 11 and the lower end wall member 13, and a horizontal air passage formed inside the lower end wall member 13.

  The first and second air supply paths 21s and 22s are connected to the pressurized air supply sources 21m and 22m, respectively, and the first and second pressure switches 21n are provided in the middle of the first and second air supply paths 21s and 22s. 22n or a pressure sensor is connected. The first and second pressure switches 21n and 22n are switched from off to on (or from on to off) when the pressure of the pressurized air in the air supply passages 21s and 22s is increased to a set pressure or higher. The first and second air discharge paths 21e and 22e are open to the outside.

Next, the first on-off valve mechanism 30 will be described.
As shown in FIGS. 2, 7, and 9, the first on-off valve mechanism 30 is disposed inside the wall portion of the upper end wall member 12 in the vicinity of the outer peripheral side of the upper end portion of the first insertion hole 12b. The downstream end of the upstream air passage 21a of the air passage 21 is provided so as to be openable and closable. The first on-off valve mechanism 30 includes a valve body 31, a cap member 32, a valve seat 32a, a hydraulic pressure introduction chamber 33 (fluid pressure introduction chamber), a hydraulic pressure introduction passage 34 (fluid pressure introduction passage), and internal air. The passages 35 a to 35 f are provided, and are incorporated into the mounting holes 36 of the upper end wall member 12 through the cap member 32 and the annular member 37.

  The mounting hole 36 is formed in the upper end wall member 12 so as to penetrate horizontally. An annular member 37 is fixedly mounted in the middle of the mounting hole 36, and its outer peripheral side is sealed by a seal member 37s. A cap member 32 that closes the open side portion of the mounting hole 36 is fixed by screwing and sealed by a seal member 32s.

  A through hole 37 a having the same diameter as the small diameter hole 36 a of the mounting hole 36 is formed in the circular wall portion of the annular member 37. The valve body 31 is attached to the accommodating chamber formed in the cap member 32 and the annular member 37, the through hole 37a, and the small diameter hole 36a so as to be movable in the horizontal direction.

  The valve body 31 includes a valve body main body 38 whose front end part can partially protrude from the cylindrical part 14a of the clamping oil chamber 14, and a movable valve body 39 that is movably fitted on the valve body main body 38. Has been. The valve body 31 can move about 1.0 to 2.0 mm in the horizontal direction with respect to the mounting hole 36. The movable valve body 39 can move relative to the valve body 38 in the horizontal direction by about 1.0 to 2.0 mm.

  The valve body 38 is formed by integrally forming a small diameter shaft portion 38a and a large diameter shaft portion 38b. The small-diameter shaft portion 38a is inserted into the small-diameter hole 36a and the through-hole 37a, and the proximal end portion of the large-diameter shaft portion 38b is slidably fitted in the concave hole 32b of the cap member 32. The movable valve body 39 is externally fitted to the large-diameter shaft portion 38 b in the accommodation chamber between the annular member 37 and the cap member 32.

  A seal member 40 for sealing the outer peripheral side of the small diameter shaft portion 38a, a seal member 41 for sealing the outer peripheral side of the large diameter shaft portion 38b, and a seal member 42 for sealing between the valve body main body 38 and the movable valve body 39 are also provided. Is provided.

  An annular air passage 35 a communicating with the upstream air passage 21 a is formed in the outer peripheral portion of the annular member 37. The air passage 35 a communicates with an air passage 35 b in the wall portion of the annular member 37. A cap-shaped air passage 35c is formed between the annular member 37 and the movable valve body 39, and a horizontally oriented air passage 35d that can communicate with the air passage 35c is formed in the cap member 32. An annular air passage 35e that communicates with the air passage 35d and an air passage 35f that communicates with the air passage 35e and communicates with the upstream end of the downstream air passage 21b are formed on the outer periphery of the cap member 32. .

  The movable valve body 39 has a small-diameter cylindrical portion 39a and a tapered cylindrical portion 39b. The tapered cylinder portion 39b has a tapered outer peripheral surface. An annular valve seat 32a for opening and closing the air passages 35c and 35d is formed on the end surface of the cap member 32. An annular valve surface 39v that can be brought into contact with and separated from the annular valve seat 32a is formed on the end surface of the tapered cylindrical portion 39b of the movable valve body 39.

  An annular engagement portion 39c that slightly protrudes toward the valve body 38 is formed on the inner peripheral portion of the distal end of the small-diameter cylindrical portion 39a, and is formed with a slightly smaller diameter at the distal end of the large-diameter shaft portion 38b of the valve body 38. The engagement shaft 38c is externally fitted so as to be relatively movable.

  A hydraulic oil introduction chamber 33 is formed between the cap member 32 and the valve body main body 38 in the concave hole 32b, and a clamp oil chamber is provided via a hydraulic introduction passage 34 formed in the valve body main body 38 so as to penetrate therethrough. It is connected to 14 cylindrical portions 14a. A plurality of branch oil passages 34 a are formed at the distal end portion of the hydraulic pressure introduction passage 34. When the hydraulic pressure is supplied to the clamp oil chamber 14, the hydraulic pressure is introduced from the hydraulic pressure introduction path 34 to the hydraulic pressure introduction chamber 33, and the hydraulic pressure urges the valve body 38 in the advancing direction (on the piston rod portion 4 c side).

Next, the operation of the hydraulic cylinder 3 and the first on-off valve mechanism 30 will be described.
When the hydraulic pressure is supplied to the clamp oil chamber 14 and the piston rod member 4a is in the middle of lowering or at the lower limit position (clamped state), the small-diameter rod portion 4d faces the first on-off valve mechanism 30. Therefore, in the first on-off valve mechanism 30, as shown in FIG. 9, the valve body 31 receives the hydraulic pressure introduced into the hydraulic pressure introduction chamber 33, the valve body main body 38 enters the advanced state, and the valve surface 39v The valve is separated from the seat 32a and switched from the valve closing state to the valve opening state, and the air passages 35a to 35f are brought into the communication state. At this time, since the annular engaging portion 39c is pushed backward by the step portion of the engaging shaft portion 38c, the valve closing state is surely changed to the valve opening state. Note that switching from the closed state to the open state corresponds to “switching of the open / close state”.

  On the other hand, when the hydraulic pressure in the clamping oil chamber 14 of the clamping device 1 is switched to the drain pressure, the hydraulic pressure is supplied to the unclamping oil chamber 15, and the clamping device 1 enters the unclamped state, as shown in FIG. Thus, the hydraulic pressure in the hydraulic pressure introducing chamber 33 becomes a drain pressure, and the valve body 38 is pushed toward the cap member 32 by the large-diameter rod portion 4e of the piston rod member 4a. Since the frictional force of the seal member 40 acts between the valve body 38 and the movable valve body 39, the movable valve body 39 also moves together with the valve body 38, and the valve surface 39v contacts the valve seat 32a. Thus, the valve opening state is switched to the valve closing state, and the space between the air passage 35c and the air passage 35d is closed.

  In this closed state, the movable valve body 39 is also urged toward the valve closing side by the air pressure acting on the movable valve body 39. By switching to the closed state, the air pressure in the upstream air passage 21a increases upstream of the first on-off valve mechanism 30, so that the piston rod member 4a reaches the rising limit position by the pressure switch 21n. Can be detected. Note that switching from the valve-open state to the valve-closed state also corresponds to “switching of the open / close state”.

  When the piston rod member 4a starts to descend from the state of FIG. 2, the position of the movable valve body 39 does not change, as shown in FIG. 7, and the valve body main body 38 is formed by the annular tapered surface 4t at the upper end of the large diameter rod portion 4e. Is slightly allowed to move forward, the stepped portion of the engagement shaft portion 38c engages with the annular engagement portion 39c, and then switches from the valve closing state to the valve opening state shown in FIG.

Next, the second on-off valve mechanism 50 will be described.
As shown in FIGS. 1, 3, 8, and 10, the second on-off valve mechanism 50 has the same structure as the first on-off valve mechanism 30. Therefore, the structure of the valve mechanism will be briefly described.

  The second on-off valve mechanism 50 is disposed in a vertical posture in the mounting hole 56 in the central portion of the lower end wall member 13, and the second on-off valve mechanism 50 is provided to open and close the downstream end of the second air passage 22. Yes. The second on-off valve mechanism 50 includes a valve body 51, a cap member 52, a valve seat 52a, a hydraulic pressure introduction chamber 53 (fluid pressure introduction chamber), a hydraulic pressure introduction passage 54 (fluid pressure introduction passage), and internal air. The passages 55 a to 55 d are provided, and are incorporated into the vertical mounting holes 56 of the lower end wall member 13 through the cap member 52 and the annular member 57.

  The cap member 52 is fixed to the lower end wall member 13 by screwing and sealed with a seal member 52s. The annular member 57 is fixed to the middle part of the mounting hole 56. A through hole 57 a having the same diameter as the small diameter hole 56 a of the mounting hole 56 is formed in the horizontal wall of the annular member 57.

  The valve body 51 includes a valve body main body 58 and a movable valve body 59. The valve body 58 is formed by integrally forming a small-diameter shaft portion 58a and a large-diameter shaft portion 58b, and the large-diameter shaft portion 58b is accommodated in an accommodation chamber 52b formed by the cap member 52 and the annular member 57. The small-diameter shaft portion 58a is slidably inserted through the small-diameter hole 56a and the through-hole 57a, and can partially protrude upward from the upper end surface of the lower end wall member 13.

  An engagement shaft portion 58c having a slightly smaller diameter is formed at the upper end portion of the large diameter shaft portion 58b. The movable valve body 59 has a small-diameter cylindrical portion 59a and a large-diameter portion 59b, and an annular engagement portion 59c externally fitted to the engagement shaft portion 58c is provided in the vicinity of the upper end of the small-diameter cylindrical portion 59a. Is formed.

  A seal member 60 that seals the outer peripheral side of the small diameter shaft portion 58a, a seal seal member 61 that seals the outer peripheral side of the large diameter shaft portion 58b, and a seal member 62 that seals between the large diameter shaft portion 58b and the movable valve element 59 are also provided. Is provided.

  As an internal air passage, an annular air passage 55 a communicating with the downstream end portion of the second air passage 22 is formed in the outer peripheral portion of the annular member 57. An air passage 55 b communicating with the annular air passage 55 a is formed in the wall portion of the annular member 57. A cap-shaped air passage 55c communicating with the air passage 55b is formed between the annular member 57 and the movable valve body 59. The cap member 52 is formed with an air passage 55d that can communicate with the air passage 55c. An annular valve seat 52 a is formed on the upper end surface of the cap member 52, and an annular valve surface 59 v capable of contacting and separating from the annular valve seat 52 a is formed on the lower surface of the movable valve body 59.

Next, the operation of the hydraulic cylinder 3 and the second on-off valve mechanism 50 will be described.
When the clamp device 1 shown in FIGS. 1 and 3 is in the unclamped state, the unclamping oil chamber 15 is filled with hydraulic pressure, so that hydraulic pressure is introduced from the hydraulic pressure introduction hole 54 to the hydraulic pressure introduction chamber 53, and the hydraulic pressure introduction chamber 53. The valve body 51 is urged upward by the hydraulic pressure and moved upward, and the movable valve body 59 is also moved upward via the engagement of the stepped portion of the annular engagement portion 59c and the small diameter shaft portion 58c. The surface 59v is separated from the annular valve seat 52a and maintains the valve open state.

  When hydraulic pressure is supplied to the clamp oil chamber 14 of the clamp device 1 and the hydraulic pressure of the unclamp oil chamber 15 is switched to the drain pressure, the piston rod member 4a is lowered to the lower limit position, and the clamp device 1 is clamped from the unclamped state to the clamped state. The piston portion 4p is in contact with the upper surface of the lower end wall member 13. Then, as shown in FIG. 10, the valve body 58 is pushed downward by the piston portion 4p, the movable valve body 59 is also moved downward by the frictional force of the seal member 62, and the annular valve surface 59v is annular. The valve is brought into contact with the valve seat 52a and switched from the open state to the closed state. As a result, since the air pressure in the second air passage 22 increases, it is possible to reliably detect that the piston rod member 4a is moved to the lower limit position by the pressure switch 22n and is in the clamped state.

  According to the hydraulic cylinder 1, the first and second on-off valve mechanisms 30 and 50 that open and close the air passages 21 and 22 in the clamp body 10 are incorporated into the mounting holes 36 and 56 formed in the cylinder body 10. Since the first and second on-off valve mechanisms 30 and 50 can be incorporated in the clamp body 10, the hydraulic cylinder 1 capable of detecting the rising limit position and the falling limit position of the output member 4 can be reduced in size.

  In the first on-off valve mechanism 30, the hydraulic pressure in the clamp oil chamber 14 is introduced into the hydraulic pressure introduction chamber 33, and the hydraulic pressure is applied to the valve body 31 so that the valve body 31 can be held in a protruding state toward the output member 4 side. It is advantageous in terms of reliability and durability. The same applies to the second on-off valve mechanism.

  When the output member 4 reaches a predetermined position, the valve members 31 and 51 are moved by the output member 4 to switch the open / close state of the first and second open / close valve mechanisms 30 and 50. The predetermined position of the output member 4 can be reliably detected via the air pressure.

  A second on-off valve mechanism 50A obtained by partially changing the second on-off valve mechanism 50 of the first embodiment will be described. However, only a change part is demonstrated, the same code | symbol is attached | subjected to the same member, and description is abbreviate | omitted. As shown in FIG. 11 and FIG. 12, a concave hole 58d that is open at the lower end and opened to the hydraulic pressure introducing chamber 53 is formed at the lower end portion of the valve body 58A, and the concave hole 58d and the hydraulic pressure introducing chamber 53 are formed. The compression coil spring 53a was attached to the. The valve body 58A is biased upward by the hydraulic pressure of the hydraulic pressure introducing chamber 53 and biased upward by the compression coil spring 53a.

  Since the compression coil spring 53a is provided, when switching from the clamped state to the unclamped state, the operation reliability of the valve body 51 at the time of transition until the hydraulic pressure charged in the unclamped oil chamber 15 rises can be improved. it can. Note that a compression spring may be incorporated in the first on-off valve mechanism 30 as described above. In addition, the same effect as the hydraulic cylinder of the first embodiment can be obtained.

  A second on-off valve mechanism 50B obtained by partially changing the second on-off valve mechanism 50 of the first embodiment will be described. However, only a change part is demonstrated, the same code | symbol is attached | subjected to the same member, and description is abbreviate | omitted. As shown in FIGS. 13 and 14, the annular member 57 is omitted. The valve body 51B includes a valve body main body 58 and a movable valve body 59B that is movably fitted on the valve body main body 58. The valve body 58 is obtained by integrally forming a small diameter shaft portion 58a and a large diameter shaft portion 58b.

  As an internal air passage, an annular air passage 55g formed on the outer peripheral side of the movable valve body 59B and communicating with the downstream end of the second air passage 22, and an annular air passage formed in the cap member 52 in a vertically penetrating manner. An air passage 55h capable of communicating with 55g is provided. An annular valve seat 52a is formed on the upper end surface of the cap member 52, and an annular valve surface 59v is formed on the lower end surface of the movable valve body 59B. As illustrated, seal members 60 to 62 are provided.

  In the unclamped state shown in FIG. 13, since the hydraulic pressure is supplied to the unclamping oil chamber 15, the valve body 58 and the movable valve body 59 </ b> B are biased upward by the hydraulic pressure introduced into the hydraulic pressure introduction chamber 53. Therefore, the annular valve surface 59v is separated from the annular valve seat 52a and is opened.

  Contrary to the above, as shown in FIG. 14, when the hydraulic pressure is supplied to the clamp oil chamber 14 and the hydraulic pressure of the unclamp oil chamber 15 is released, the piston rod member 4a is lowered to the lower limit position, and the piston portion 4p. Comes into contact with the upper surface of the lower end wall member 13. As a result, the valve body 58 is lowered, the movable valve body 59B is lowered integrally with the valve body 58 via the frictional force of the seal member 62, and the annular valve surface 59v contacts the annular valve seat 52a and closes. It becomes a valve state. Therefore, since the air pressure in the second air passage 22 increases, it can be detected by the pressure switch 22n that the piston rod member 4a has reached the lower limit position. In addition, the same effect as the hydraulic cylinder of the first embodiment can be obtained.

  A second on-off valve mechanism 50C obtained by partially changing the second on-off valve mechanism 50B of the third embodiment will be described. However, only a change part is demonstrated, the same code | symbol is attached | subjected to the same member, and description is abbreviate | omitted. As shown in FIGS. 15 and 16, the annular member 57 is omitted.

  The valve body 51C includes a valve body main body 58 and a movable valve body 59B. A cup-shaped cup member 52c is fixed inside the cap member 52C, and the large-diameter shaft portion 58b of the valve body 58 is slidably mounted in the accommodation hole of the cup member 52c.

  An annular valve seat 52a is formed on the upper end surfaces of the cap member 52C and the cup member 52c, and an annular valve surface 59v is formed on the lower end of the movable valve body 59B. As an internal air passage, an annular air passage 55g on the outer peripheral side of the movable valve body 59B, an annular air passage 55i between the cup member 52c and the cap member 52C, and an annular air passage 55i formed on the bottom wall of the cap member 52C. An air passage 55j communicating with the air passage 55 is formed. The air passage 55j is open to the outside through the second air discharge passage 22e.

  As shown in FIG. 15, when in the unclamped state, the hydraulic pressure in the unclamping oil chamber 15 is introduced into the hydraulic pressure introducing chamber 53, so that the annular valve surface 59v is formed in the annular valve seat as in the second on-off valve mechanism 50B. The valve is opened away from 52a. In the clamped state, the annular valve surface 59v comes into contact with the annular valve seat 52a and closes in the same manner as the second on-off valve mechanism 50B. This second on-off valve mechanism 50C is advantageous in terms of manufacturing because the accuracy requirements for parts are alleviated. In addition, the same effect as the hydraulic cylinder of the first embodiment can be obtained.

  In this clamping device 1D, a first on-off valve mechanism 30D is provided instead of the first on-off valve mechanism 30 of the first embodiment, and a second on-off valve mechanism 50 is provided instead of the second on-off valve mechanism 50 of the first embodiment. 50D is provided, and the other configuration is the same as that of the embodiment. Therefore, the same members are denoted by the same reference numerals and the description thereof is omitted.

  The first on-off valve mechanism 30 is closed when the output member 4 is at the upper limit position, and is opened when the output member 4 is at the lower limit position. However, the first on-off valve mechanism 30D is opened when the output member 4 is at the upper limit position, and is closed when the output member 4 is at the lower limit position. As shown in FIGS. 17 to 24, the first on-off valve mechanism 30D includes a cap member 32, an annular member 37D, a valve body 31D, a hydraulic pressure introduction chamber 33, a hydraulic pressure introduction passage 34, and an internal air passage 35a. , 35b, 35g, and 35h, and is mounted in a horizontal mounting hole 36 formed in the upper end wall member 12. The valve body 31D is configured only by the valve body main body 38, and the valve body main body 38 is formed by integrally forming a small diameter shaft portion 38a and a large diameter shaft portion 38b.

  The large diameter shaft portion 38b is movably accommodated in a storage chamber 32b formed by the cap member 32 and the annular member 37D, and the small diameter shaft portion 38a is formed in the through hole 37a of the annular member 37 and the small diameter hole 36a of the mounting hole 36. It is slidably inserted. Seal members 32s, 40, 41 are also provided.

  As an internal air passage, an air passage 35a that communicates with the upstream air passage 21a and is formed in the outer peripheral portion of the annular member 37, an air passage 35b that is formed in the wall portion of the annular member 37D, and the air passage 35b An annular air passage 35g formed in the inner peripheral portion of the annular member 37D so as to communicate with the air passage 35h formed between the cap member 32 and the annular member 37 and communicated with the upstream end of the downstream air passage 21b; Is formed. An annular valve surface 38c is formed on the end surface of the large-diameter shaft portion 38b of the valve body 38, and an annular valve seat 37b that can contact and separate from the annular valve surface 38c is formed on the end surface of the annular member 37D.

  As shown in FIG. 18, when the clamp device 1 is in the unclamped state and the piston rod member 4a is at the upper limit position, the valve body 38 is pushed toward the cap member 32 by the large-diameter rod portion 4e of the piston rod member 4a. Then, since the annular member 37D does not move, the annular valve surface 38c is separated from the annular valve seat 37b and is opened. As a result, the air pressure in the upstream air passage 21a of the first air passage 21 decreases, so that the pressure switch 21n can detect that the output member 4 has reached the rising limit position. Even when the output member 4 is slightly lowered, the valve closed state is maintained as shown in FIG.

  Contrary to the above, when the clamp state is reached and the hydraulic pressure is supplied to the clamp hydraulic pressure 14, the hydraulic pressure is introduced from the hydraulic pressure introduction path 34 to the hydraulic pressure introduction chamber 33 as shown in FIG. In order to advance toward the member 4 (small-diameter rod portion 4d) side, the annular valve surface 38c comes into contact with the annular valve seat 37b to be closed. As a result, since the air pressure in the upstream air passage 21a increases, it can be detected that the output member 4 has been lowered from the ascent limit position by the pressure switch 21n.

Next, the second on-off valve mechanism 50D will be described.
As shown in FIG. 19, the second on-off valve mechanism 50D includes a cap member 52, an annular member 57D, a valve body 51, a hydraulic pressure introduction chamber 53, a hydraulic pressure introduction path 54, and internal air passages 55a and 55b. 55g and 55h, and mounted in a vertical mounting hole 56 formed in the lower end wall member 13. The valve body 51 is configured only by the valve body main body 58, and the valve body main body 58 is formed by integrally forming a small diameter shaft portion 58a and a large diameter shaft portion 58b. The large diameter shaft portion 58b is movably accommodated in an accommodation chamber 52b formed by the cap member 52 and the annular member 57D, and the small diameter shaft portion 58a is formed in the through hole 57a of the annular member 57D and the small diameter hole 56a of the mounting hole 56. It is slidably inserted. Seal members 52s, 60, 61 are also provided.

  As an internal air passage, an air passage 55a formed in the outer peripheral portion of the annular member 57D so as to communicate with the second air passage 22, and a wall portion of the annular member 57D so as to communicate with the air passage 55a. An air passage 55b, an annular air passage 55g formed in the inner periphery of the annular member 57D so as to communicate with the air passage 55b, and the second air discharge passage formed between the cap member 52 and the annular member 57D. An air passage 55h communicating with 22e is formed. An annular valve surface 58c is formed on the end surface of the large-diameter shaft portion 58b of the valve body 58, and an annular valve seat 57b that can contact and separate from the annular valve surface 58c is formed on the end surface of the annular member 57D.

  As shown in FIG. 19, when the clamping device 1D is in the unclamped state and the hydraulic pressure is supplied to the unclamping oil chamber 15 and the piston rod member 4a is not at the lower ascending limit position, the hydraulic pressure introducing chamber 54 is connected to the hydraulic pressure introducing chamber. Since the hydraulic pressure is introduced to 53 and the valve body 58 slightly moves upward, the annular valve surface 58c comes into contact with the annular valve seat 57b to be closed. As a result, since the air pressure in the second air passage 22 increases, it can be detected by the pressure switch 22n that the output member 4 has risen from the lower limit position.

  On the other hand, as shown in FIGS. 22 and 24, when the hydraulic pressure is supplied to the clamp oil chamber 14 and the clamp oil chamber 14 is brought into the clamp state, the piston rod member 4a is lowered to the lower limit position, and the piston portion 4p is placed on the upper surface of the lower end wall member 13. The valve body 58 is pushed to the cap member 52 side and the annular member 57D does not move, so that the annular valve surface 58c is separated from the annular valve seat 57b and is opened. As a result, since the air pressure in the second air passage 22 decreases, it can be detected by the pressure switch 22n that the output member 4 has reached the lower limit position. In addition, the same effect as the hydraulic cylinder of the first embodiment can be obtained.

It is an example at the time of applying this invention to the hydraulic cylinder 3E applied to a clamp apparatus.
As shown in FIGS. 25 to 27, the hydraulic cylinder 3E of the clamp device 1E includes a cylinder body 70, an output member 73, a clamp oil chamber 74, an unclamp oil chamber 75, an on-off valve mechanism 76, and pressurized air. Is provided with an air passage 85s for supplying air, an air passage 77 for discharging pressurized air, and the like. FIG. 25 shows the hydraulic cylinder 3E when the clamp device is in a clamped state. The hydraulic cylinder 3E is used in a state of being fitted into a recessed hole 78a of a base member 78 such as a work pallet. The clamp oil chamber 74 and the unclamp oil chamber 75 are connected to a hydraulic pressure supply source. The air passage 85s is connected to a pressurized air supply source via an air supply passage (not shown), and a pressure switch or a pressure sensor is connected to the air supply passage. The air passage 77 is open to the outside.

  The output member 73 is formed by integrally forming a rod portion 73a and a piston portion 73b. The cylinder main body 70 includes a cylinder member 71 and an upper end wall member 72.

  The on-off valve mechanism 76 has a structure similar to that of the on-off valve mechanism 50D, and will be described briefly. The on-off valve mechanism 76 is mounted in the vertical mounting hole 72a of the upper end wall member 72 so as to face the piston portion 73b. The on-off valve mechanism 76 includes a cap member 79, a valve body 80, an annular member 81, a hydraulic pressure introduction chamber 82, a hydraulic pressure introduction path 83, internal air passages 85a, 85b, 85c, and the like.

  The valve body 80 is formed by integrally forming a small diameter shaft portion 80a and a large diameter shaft portion 80b. The large-diameter shaft portion 80 b is movably inserted into a hole formed in the upper end wall member 72 and sealed with a seal member 84. The small diameter shaft portion 80 a is slidably inserted into the through hole 81 a of the annular member 81 and the insertion hole 79 a of the cap member 79, and can project from the lower surface of the upper end wall member 72. A seal member 85 that seals between the small diameter shaft portion 80a and the cap member 79 is also provided.

  As an internal air passage, an annular air passage 85a that communicates with the air passage 85s, an annular air passage 85b that can communicate with the air passage 85a and is formed in the inner peripheral portion of the annular member 81, and the air passage 85b. And an air passage 85c formed in the wall portion of the annular member 81 and an air passage 85c communicating with the discharge air passage 77. An annular valve seat 81a is formed on the upper surface of the annular member 81, and an annular valve surface 80v capable of contacting and separating from the annular valve seat 81a is formed at the lower end of the large diameter shaft portion 80b.

  In the unclamped state in which the hydraulic pressure is supplied to the unclamping oil chamber 75 and the hydraulic pressure in the clamping oil chamber 74 is released, as shown in FIG. 26, the hydraulic pressure is introduced from the hydraulic pressure introduction path 83 into the hydraulic pressure introduction chamber 82. The valve body 80 for receiving the pressure moves downward, and the annular valve surface 80v comes into contact with the annular valve seat 81a so that the valve is closed. As a result, since the air pressure in the air passage 85s becomes high, it can be detected by the pressure switch or the pressure sensor that the air pressure has dropped from the rising limit position.

  Contrary to the above, in the clamped state in which the hydraulic pressure is supplied to the clamp oil chamber 74 and the hydraulic pressure is released from the unclamp oil chamber 75, the output member 73 reaches the rising limit position as shown in FIG. Since the valve body 80 is pushed upward at 73b, the annular valve surface 80v is separated from the annular valve seat 81a and is opened, and the air pressure in the air passage 76 is reduced. It can be detected that the clamp state has been reached. In addition, the same effect as the hydraulic cylinder of the first embodiment can be obtained.

A clamp device according to this embodiment will be described with reference to FIGS.
In the clamping device 1F, the output member 4F is twisted by 90 ° around the shaft center during the first descending period when the output member 4F descends from the ascending limit position, and then moves to the descending limit position without being twisted to be in a clamped state. . Further, the output member rises without being twisted in the first rising stage when the output member 4F rises from the clamped state, and then the output member 4F is twisted by 90 ° around the axis and enters the unclamped state in the latter half of the rising.

  The hydraulic cylinder 3F has an output member 4F (clamp rod, that is, a piston rod member 90), and a clamp arm 91 is fixed to the upper end portion of the output member 4F. The cylinder body 92 has a cylinder hole 93, and a rod insertion hole 94 a is formed in the lower end wall member 94 of the cylinder body 92.

  A piston portion 90a that slides in the cylinder hole 93 is formed in the middle portion of the piston rod member 90. In the cylinder hole 93, a clamp oil chamber 95 is formed on the upper side of the piston portion 90a. An unclamping oil chamber 96 is formed on the side.

  The twist mechanism 100 for twisting the piston rod member 90 includes a plurality of cam grooves 101 formed in the outer periphery of the piston rod member 90 in the unclamping oil chamber 96 and a plurality of cam grooves 101 held by the lower end wall member 94. A plurality of steel balls 103 engaged with each other are provided. The cam groove 101 includes a vertical linear groove 101a in the upper half of the cam groove 101 and a spiral groove 101b continuous with the lower end of the linear groove 101a.

  The clamp device 1F has an opening / closing for detecting that the piston rod member 90 has completed the twisting operation when the piston rod member 90 shifts from the unclamped state to the clamped state (the piston rod member 90 is lowered). A valve mechanism 50F is provided.

  Since this on-off valve mechanism 50F has substantially the same structure as that of the second on-off valve mechanism 50 of the first embodiment, the same reference numerals will be given to the same members and the description will be made briefly.

  The on-off valve mechanism 50F includes a mounting hole 56 formed in the lower end wall member 94 in the horizontal direction, a valve body 51, a cap member 52, an annular member 57, a hydraulic pressure introduction chamber 53, and a hydraulic pressure introduction path 54. And. The valve body 51 includes a valve body main body 58 and a movable valve body 59. The movable valve body 59 has an annular engagement portion, and the valve body main body 58 has a small diameter shaft portion.

  The air passage 23 formed in the lower end wall member 94 is connected to an air supply source via an air supply path, and a pressure switch or a pressure sensor is connected to the air supply path. The discharge air passage 24 formed in the lower end wall member 94 is open to the outside.

  As an air passage inside the on-off valve mechanism 50F, an annular air passage 55a formed in the outer peripheral portion of the annular member 57 so as to communicate with the air passage 23, an air passage 55b formed in the annular member 57, and the annular member 57 And a cap-shaped air passage 55c formed between the movable valve body 59 and an air passage 55d formed in the cap member 52 so as to communicate with the air passage 55c and communicated with the discharge air passage 24. Has been. An annular valve seat 52a is formed on the end surface of the cap member 52, and an annular valve surface 59v that can contact and separate from the annular valve seat 52a is formed on the movable valve body 59.

  In the unclamping oil chamber 96, the outer periphery of the piston rod member 90 is a detection groove 102 similar to the cam groove 101, and a hemispherical tip of the valve body 58 of the on-off valve mechanism 50F is engaged. A matching detection groove 102 is formed. The detection groove 102 has a straight groove 102a in the upper half of the groove and a spiral groove 102b connected to the lower end of the straight groove 102a. The spiral groove 102b is formed deep, and the straight groove 102a is formed to a depth of about ½ of the spiral groove 102b. In the unclamped state, the hydraulic pressure in the unclamping oil chamber 96 is introduced from the hydraulic pressure introduction path 54 to the hydraulic pressure introduction chamber 53, and the tip of the valve body 58 protrudes into the spiral groove 102b. Therefore, as shown in FIG. 29 and FIG. 30, the annular valve surface 59v is separated from the annular valve seat 52a and is opened. As a result, the air pressure in the air passage 23 decreases.

  When the hydraulic pressure is supplied to the clamp oil chamber 95 while releasing the hydraulic pressure of the unclamping oil chamber 96, the piston rod member 90 descends, and the tip of the valve body 58 is linear as shown in FIGS. It will be in the state engaged with the groove | channel 102a. Then, since the valve body 58 is pushed toward the cap member 52 by the piston rod member 90, the annular valve surface 59v comes into contact with the annular valve seat 52a to be closed. As a result, the air pressure in the air supply passage on the upstream side of the air passage 23 increases, so that it can be detected by a pressure switch or a pressure sensor. That is, the twist operation completion position of the piston rod member 90 can be reliably detected based on the pressure switch signal. The twist operation completion position of the piston rod member 90 corresponds to “a predetermined position of the output member”. In addition, the same effect as the hydraulic cylinder of the first embodiment can be obtained.

  A clamping device 1G according to the eighth embodiment will be described with reference to FIGS. This clamping device 1G is the same as the clamping device 1F of the seventh embodiment, but the structure of the on-off valve mechanism 30G is different. Therefore, the same reference numerals are assigned to the same members as those of the clamp device 1F of the seventh embodiment, and the description thereof is omitted, and the on-off valve mechanism 30G will be described.

  Since this on-off valve mechanism 30G is the same as the first on-off valve mechanism 30D of the fifth embodiment, the same members are denoted by the same reference numerals and will be briefly described. The on-off valve mechanism 50F of the seventh embodiment is opened when the output member 4F is being twisted, and the output member 4F is closed after the twist operation is completed. However, the on-off valve mechanism 30G is closed when the output member 4F is twisted, and the valve is opened after the output member 4F is completed.

  The on-off valve mechanism 30G includes a cap member 32, an annular member 37D, a valve body 31D, a hydraulic pressure introduction chamber 33, a hydraulic pressure introduction path 34, and internal air passages 35i, 35j, 35k, 35m, and 35n. It is mounted in a horizontal mounting hole 36 formed in the lower end wall member 94. The valve body 31D is configured only by the valve body main body 38, and the valve body main body 38 is formed by integrally forming a small diameter shaft portion 38a and a large diameter shaft portion 38b.

  The large-diameter shaft portion 38b is movably accommodated in a housing chamber formed by the cap member 32 and the annular member 37D, and the small-diameter shaft portion 38a is slid into the through-hole 37a of the annular member 37D and the small-diameter hole 36a of the mounting hole 36. It is inserted freely.

  As an internal air passage, the air passage 35i communicated with the air passage 23 and formed in the outer peripheral portion of the annular member 37D, the air passage 35j formed in the wall portion of the annular member 37D, and the air passage 35j. An annular air passage 35k formed in the inner peripheral portion of the annular member 37D, an annular air passage 35m that can communicate with the air passage 35k, and a cap member 32 that communicates with the air passage 35m. An air passage 35n that is in communication with the air passage 24 is formed. An annular valve seat 38c is formed on the end surface of the large-diameter shaft portion 38b of the valve body 38, and an annular valve seat 37b that can contact and separate from the annular valve surface 38c is formed on the end surface of the annular member 37D.

  As shown in FIG. 34, when the piston rod member 90 is lowered to switch from the unclamped state to the clamped state, the distal end portion of the valve body 38 is moved into the spiral groove 102b while the piston rod member 90 is being twisted. Therefore, the annular valve surface 38c and the annular valve seat 37b come into contact with each other to be closed, and the air pressure in the air supply passage for supplying pressurized air to the air passage 23 is maintained at a high pressure.

  On the other hand, as shown in FIG. 36, after the piston rod member 90 completes the twisting operation, the tip of the valve body 38 is engaged with the linear groove 102a. Then, since the valve body 38 is pushed toward the cap member 32, the annular valve surface 38c is separated from the annular valve seat 37b and is opened, so that pressurized air is supplied to the air passage 23. The air pressure in the air supply passage is reduced. Therefore, the twist operation completion position of the piston rod member 90 can be reliably detected based on the signal from the pressure switch. In addition, the same effect as the hydraulic cylinder of the first embodiment can be obtained.

An example in which the embodiment is partially changed will be described.
1) It is also possible to provide one pressure switch or pressure sensor common to a plurality of air supply passages for supplying pressurized air to a plurality of air passages in a plurality of on-off valve mechanisms.

  2) In the above embodiment, the hydraulic cylinder has been described as an example of the fluid pressure cylinder. However, the present invention can be similarly applied to an air cylinder as the fluid pressure cylinder.

  3) The structure of the cylinder body, the structure of the piston rod member, and the like show examples, and various modifications can be added to these structures without departing from the spirit of the present invention.

  4) The structures of the above various on-off valve mechanisms are also exemplary, and are not limited to these on-off valve mechanisms, and various on-off valve mechanisms can be employed without departing from the spirit of the present invention. .

  The fluid pressure cylinder according to the present invention can be employed in a hydraulic cylinder or an air cylinder applied to a clamp device or other mechanical devices.

1, 1D, 1F, 1G Clamp device 10, 70, 92 Cylinder body 3, 3E, 3F, 3G Hydraulic cylinder 4, 4F, 4G, 73 Output member 14, 74, 95 Clamp oil chamber 15, 75, 96 Unclamp oil Chambers 21, 22, 23, 24 Air passages 30, 30D, 30G, 50, 50A On-off valve mechanisms 50B, 50C, 50D, 50F, 76 On-off valve mechanisms 31, 31D, 51, 51B, 51C, 80 Valve bodies 32a, 37b , 52a, 57b, 81a Valve seats 33, 53, 82 Hydraulic introduction chambers 34, 54, 83 Hydraulic introduction passages 36, 72a, 56 Mounting holes 32, 52, 52C, 79 Cap members 42, 62 Seal members 53a Compression coil springs

A fluid pressure cylinder according to the present invention includes a cylinder main body, an output member equipped to be able to advance and retreat in the cylinder main body, a fluid chamber for driving the output member to at least one of an advancing side and a retracting side, A fluid pressure cylinder comprising an air passage formed in a cylinder body, supplied with pressurized air at one end and communicated with the outside at the other end, and an on-off valve mechanism capable of opening and closing the air passage, The on-off valve mechanism is mounted in a mounting hole formed in the cylinder body so as to be able to advance and retreat, and a small-diameter shaft portion and a large-diameter shaft portion provided on the opposite side of the fluid chamber with respect to the small-diameter shaft portion are integrally formed. A valve body including a valve body, and an elastic member that elastically biases the large-diameter shaft portion of the valve body toward the fluid chamber and holds the valve body advanced to the fluid chamber. Provided in the middle of the mounting hole of the cylinder body, An annular member having a through-hole through which the small-diameter shaft portion of the body main body is inserted, and a cap having a concave hole fixed to the open side portion of the mounting hole and into which the large-diameter shaft portion of the valve body main body is fitted. A member, a space formed between the annular member and the cap member, for accommodating the valve body, and formed so as to extend in a radial direction of the ring member, and the chamber is defined as the one end of the air passage. A first air passage that communicates with a portion side, and a second air passage that is formed in the cap member and communicates the storage chamber with the other end portion side of the air passage, and the output member is at a predetermined position. If not, the on-off valve mechanism holds the valve body in a state where it has advanced into the fluid chamber, maintains an open state in which the first air passage and the second air passage are opened, and the output member is predetermined. When the position of The valve body is moved to switch the open / close state of the open / close valve mechanism to a closed state in which the first air passage and the second air passage are closed, and the output member is connected to the predetermined member via the air pressure in the air passage. It is configured to be able to detect that the position has been reached.

4) The structures of the above various on-off valve mechanisms are also exemplary, and are not limited to these on-off valve mechanisms, and various on-off valve mechanisms can be employed without departing from the spirit of the present invention. . The following are also examples.
The first fluid pressure cylinder has a cylinder main body, an output member that is mounted on the cylinder main body so as to be able to advance and retreat, and a fluid chamber that drives the output member to at least one of the advancing side and the retracting side. The pressure cylinder includes an air passage formed in the cylinder body, supplied with pressurized air at one end and communicated with the outside at the other end, and an on-off valve mechanism capable of opening and closing the air passage. The mechanism includes a valve body that is movably mounted in a mounting hole formed in the cylinder body and whose tip protrudes into the fluid chamber, a valve seat that can contact the valve body, and fluid pressure in the fluid chamber. A fluid pressure introduction chamber that holds the valve body in a state of being advanced to the output member side, and a fluid pressure introduction path that communicates the fluid chamber and the fluid pressure introduction chamber.
When the output member reaches a predetermined position, the valve body is moved by the output member to switch the open / close state of the on-off valve mechanism, and the output member is moved to the predetermined position via the air pressure of the air passage. It is characterized in that it can detect that the position has been reached.
In the first fluid pressure cylinder, the on-off valve mechanism maintains the valve opening state in which the valve body is separated from the valve seat in a state where the fluid pressure is supplied to the fluid chamber. When the fluid pressure in the fluid chamber is switched to the drain pressure and the output member reaches a predetermined position, the on-off valve mechanism is switched to a closed state in which the valve body is in contact with the valve seat. It is characterized by.
In the first fluid pressure cylinder, when the fluid pressure is supplied to the fluid chamber, the on-off valve mechanism maintains the valve closed state in which the valve body is in contact with the valve seat. When the fluid pressure in the fluid chamber is switched to the drain pressure and the output member reaches a predetermined position, the on-off valve mechanism is switched to an open state in which the valve body is separated from the valve seat. It is characterized by.
The fourth fluid pressure cylinder is a second fluid pressure cylinder, wherein the on-off valve mechanism is inserted and screwed into the mounting hole formed in the cylinder body, and the valve body is inserted so as to be able to advance and retract. The valve member is formed at the output member side end portion of the cap member, and the fluid pressure introducing chamber is formed between the cap member and the valve body.
The fifth fluid pressure cylinder is the fourth fluid pressure cylinder, wherein the valve body is a valve body main body and a movable valve body that is externally fitted to the valve body main body and can approach and separate from the valve seat. And a seal member is provided between the valve body main body and the movable valve body.
The sixth fluid pressure cylinder is characterized in that, in the first fluid pressure cylinder, the fluid pressure introduction path of the on-off valve mechanism is formed in a penetrating manner in the valve body.
The seventh fluid pressure cylinder is characterized in that, in the first fluid pressure cylinder, the on-off valve mechanism includes an elastic member that elastically biases the valve body toward the output member.
The eighth fluid pressure cylinder is characterized in that, in the first fluid pressure cylinder, the predetermined position is any one of an upper limit position, an operation intermediate position, and a lower limit position of the output member.
The clamp device includes a clamp rod made of the output member, and is configured to drive the clamp rod by an eighth fluid pressure cylinder.
According to the first fluid pressure cylinder, an on-off valve mechanism for opening and closing an air passage in the cylinder body is provided, and the on-off valve mechanism includes a valve body, a valve seat, a fluid pressure introduction chamber, and a fluid pressure introduction path, By incorporating the valve body into the mounting hole formed in the clamp body, the on-off valve mechanism can be incorporated into the cylinder body, so that the fluid pressure cylinder can be reduced in size.
The fluid pressure in the fluid chamber of the fluid pressure cylinder is configured to be able to be introduced into the fluid pressure introduction chamber of the on-off valve mechanism via the fluid pressure introduction path, and when the output member does not reach the predetermined position, the fluid pressure in the fluid chamber Thus, the valve body can be held in a state of projecting toward the fluid chamber, and the open / close state of the open / close valve mechanism can be maintained. Since the valve body is biased by utilizing the fluid pressure in the fluid chamber, it is advantageous in terms of reliability and durability.
When the output member reaches a predetermined position, the valve body is moved by the output member so that the open / close state of the open / close valve mechanism is switched reliably, so that the predetermined position of the output member is reliably set via the air pressure of the air passage. It can be detected.
According to the second fluid pressure cylinder, it is possible to detect that the output member has reached a predetermined position via the air pressure changed from the state where the air passage is communicated to the state where the air passage is blocked.
According to the third fluid pressure cylinder, it is possible to detect that the output member has reached the predetermined position via the air pressure changed from the state where the air passage is blocked to the state where the air passage is communicated.
According to the fourth fluid pressure cylinder, the on-off valve mechanism can be compactly incorporated in the cylinder body.
According to the fifth fluid pressure cylinder, since the frictional force is generated between the main body portion and the valve member by the seal member when the main body portion moves, the valve member is moved following the movement of the main body portion. be able to.
According to the sixth fluid pressure cylinder, it is not necessary to form a fluid pressure introduction path in the cylinder body, and the on-off valve mechanism can be configured compactly.
According to the seventh fluid pressure cylinder, when the fluid pressure in the fluid chamber is switched to the drain pressure, the open / close state of the on-off valve mechanism can be maintained until the output member reaches a predetermined position.
According to the eighth fluid pressure cylinder, the output member has an upper limit position, an operating position, and a lower limit position.
It is possible to reliably detect that any one of the positions has been reached.
According to the clamp device, the same effect as that of the first fluid pressure cylinder can be obtained in the clamp device of the type in which the clamp rod is driven by the fluid pressure cylinder.

Claims (9)

In a fluid pressure cylinder having a cylinder body, an output member equipped to be able to advance and retreat in the cylinder body, and a fluid chamber for driving the output member to at least one of an advance side and a retract side,
An air passage formed in the cylinder body, supplied with pressurized air at one end and communicated with the outside at the other end, and an on-off valve mechanism capable of opening and closing the air passage;
The on-off valve mechanism is mounted in a mounting hole formed in the cylinder body so as to be able to advance and retreat, and has a valve body with a tip projecting into the fluid chamber, a valve seat with which the valve body can contact, A fluid pressure introduction chamber for holding the valve body in a state of being advanced to the output member side by fluid pressure, and a fluid pressure introduction passage for communicating the fluid chamber and the fluid pressure introduction chamber,
When the output member reaches a predetermined position, the valve body is moved by the output member to switch the open / close state of the on-off valve mechanism, and the output member is moved to the predetermined position via the air pressure of the air passage. A fluid pressure cylinder configured to be able to detect that the position has been reached. In a state where fluid pressure is supplied to the fluid chamber, the on-off valve mechanism maintains an open state in which the valve body is separated from the valve seat,
When the fluid pressure in the fluid chamber is switched to the drain pressure and the output member reaches the predetermined position, the on-off valve mechanism is switched to a valve closing state in which the valve body is in contact with the valve seat. The fluid pressure cylinder according to claim 1, wherein When fluid pressure is supplied to the fluid chamber, the on-off valve mechanism maintains a closed state in which the valve body is in contact with the valve seat,
When the fluid pressure in the fluid chamber is switched to the drain pressure and the output member reaches the predetermined position, the on-off valve mechanism is switched to an open state in which the valve body is separated from the valve seat. The fluid pressure cylinder according to claim 1. The on-off valve mechanism includes a cap member that is inserted into and screwed into the mounting hole formed in the cylinder body, and the valve body is inserted so as to be able to advance and retract.
The said cap member is formed with the said valve seat in the said output member side edge part, The said fluid pressure introduction chamber is formed between the said cap member and the said valve body, The Claim 2 characterized by the above-mentioned. Fluid pressure cylinder.   The valve body includes a valve body main body and a movable valve body that is externally fitted to the valve body main body and that can be moved toward and away from the valve seat, and the valve body between the valve body main body and the movable valve body. The fluid pressure cylinder according to claim 4, wherein a seal member is provided on the cylinder.   The fluid pressure cylinder according to claim 1, wherein the fluid pressure introduction path of the on-off valve mechanism is formed to penetrate the valve body.   The fluid pressure cylinder according to claim 1, wherein the on-off valve mechanism includes an elastic member that elastically urges the valve body toward the output member.   2. The fluid pressure cylinder according to claim 1, wherein the predetermined position is any one of an ascending limit position, an operating halfway position, and a descending limit position of the output member.   A clamp device comprising a clamp rod made of the output member, wherein the clamp rod is driven by the fluid pressure cylinder according to claim 8.

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