TW200307591A - Hydraulic cylinder and clamping apparatus - Google Patents

Abstract

A hydraulic cylinder and a clamping apparatus are provided to fix a piston rod in a predetermined position and to add spring force on the piston rod at the predetermined position. The piston rod is fixed onto a piston installed into a cylinder body. A breaking unit is set inside a breaking cylindrical body, and the piston rod that is at a position with a predetermined stroke is limited in backward direction by the breaking unit. The breaking unit is given a loading in forward direction by a taper rod that energizes the breaking by using a spring. Even if the fluid that flows into the fluid room is drained out, the piston rod can be loaded forwards through the breaking unit by using the taper rod.

Description

200307591 V. Description of the invention (1) [Technical field to which the invention belongs] The present invention relates to a hydraulic cylinder that moves a piston rod back and forth in the axial direction by the pressure of a fluid such as compressed air, and particularly to a hydraulic cylinder suitable for positioning a panel material. Useful technique for fixing clamp devices. [Prior Art] For example, an automobile body is formed by assembling a plurality of panel materials each constituting the body using a joining device such as spot welding. When assembling an automobile body, for example, as disclosed in Japanese Unexamined Patent Publication No. Hei 4-2 3 083 0 published earlier in this patent, as a state in which panel materials are connected on a conveying trolley by a clamp member, it can be The transfer vehicle is moved on a vehicle body assembly line having work tables arranged at predetermined intervals, and predetermined assembly operations such as spot welding are performed on each work table. If the final workbench and the original workbench of the body assembly line are connected by a realignment line, the transfer cart can be recycled. On the transfer trolley, a clamp member for fixing the panel material is required while the panel material is positioned. When the gripper member is driven by a pneumatic cylinder, a pipe for supplying air pressure to a pneumatic cylinder for operating the gripper member must be removed from the transfer trolley while the transfer trolley is moving. Therefore, in the initial work and the final work table, the compressed air is supplied to the pneumatic cylinders for operating the clamp members provided on the transfer trolley to open and close the clamp members. However, these intermediate tables must be moved when the transmission trolley is moved. It is in the state of detaching the piping from the transfer trolley, and it is necessary to keep the panel material in a sweet position. Therefore, in order to stop the air pressure for moving the clamp member,

11433pif.ptd Page 5 200307591 V. Description of the invention (2) When the air pressure of the cylinder is supplied, the piston rod is stopped, and sometimes a pneumatic cylinder with a brake is used. However, a pneumatic cylinder having a brake must prevent the piston rod connected by the clamp from loosening, and cannot continuously apply a clamping force to the clamp member. Therefore, once an impact force acts on the clamp member during the conveying process to loosen the clamp member, a clamping force, that is, a coupling force, cannot be applied to the panel, and the panel material will loosen. [Summary of the Invention] An object of the present invention is to provide a hydraulic cylinder that can fix a piston rod at a predetermined position, and at the same time can apply a load in the axial direction to the piston rod at the fixed position. Another object of the present invention is to provide a clamp capable of exerting a clamping force on a panel material even when the cylinder material having a piston rod driven by hydraulic pressure is used to tighten the panel material, even if the supply of hydraulic pressure to the cylinder is stopped. Device. The hydraulic cylinder of the present invention includes a cylinder main body with an end cover at one end and a rod cover at one end, and is installed in the cylinder to move back and forth in the axial direction and is divided into The pistons of the forward fluid chamber and the backward fluid chamber are mounted on the cylinder body so as to move back and forth in the axial direction. The piston rod is fixed to the piston and protrudes from the rod cover to the outside. The piston rod is set freely in a combined state and a released state. When the piston rod is moved to a predetermined position, a braking device that restricts the return movement of the piston rod, and is used for the braking device to advance and retreat.

1 1433pi f.ptd Page 6 200307591 V. Description of the invention (3) A plunger (p 1 unger) member which can be moved freely and a spring member provided with the spring force provided in the plunger member in the direction of entry and exit; A load-loading device that applies a load in a forward direction or a backward direction to the braking device; characterized in that when the braking device is in a coupled state, even if the fluid in the fluid chamber is discharged, the load-loading device is used to A load is applied to the piston rod by the braking device. The clamp device of the present invention includes a cylinder body having a cylinder body with an end cover at one end and a rod cover at one end, and the cylinder body is freely installed in the cylinder body to move back and forth in the axial direction. A piston divided into a forward fluid chamber and a backward fluid chamber is mounted on the cylinder body so as to move back and forth in the axial direction, and is fixed to the piston and a piston rod protruding from the rod cover to the outside, A clamping rocker arm that is connected to the piston rod and clamps the workpiece by the forward or backward movement of the piston rod, and the piston rod is freely moved in a coupled state and a released state. When the piston rod moves to a predetermined position, Position of the brake device for restricting the return movement of the piston rod, a plunger member provided for the brake device to be moved forward and backward freely, and an elastic bomb provided to the plunger member to enter and exit篑 member; a load-loading device having a load applied in a forward direction or a backward direction on the braking device; When the actuating means becomes engaged state, even if the fluid within the fluid chamber is discharged, but also by the above-described loading means load and said means for applying a braking load to the piston rod above. [Embodiment]

1 1433pi f.ptd Page 7 200307591 V. Description of the Invention (4) The embodiments of the present invention will be described in detail below with reference to the drawings. Fig. 1 is a plan view showing a part of an assembly line of an automobile body for conveying a panel material constituting the automobile body by a conveyance trolley. The transfer cart 10 has a plurality of wheels 1 1 and travels from the first table s 1 to the final table Sn. At the first workbench S1, the panel material constituting the vehicle body is carried into the transfer cart 10 as a work W, and at the final workbench Sη, the workpiece W at the end of a predetermined assembly operation is removed from the transfer cart. Each conveyor 10 is provided with a clamping device 12 for clamping and connecting the workpiece W. In FIG. 1, two gripper devices 12 are provided on each of the transfer carts 10, but any number of gripper devices 12 may be provided on the transfer cart according to the size of the workpiece W. FIG. 2 is an enlarged front view showing the clamp device 12 shown in FIG. 1. A workpiece support table 1 3 for supporting a workpiece W is provided on the conveyance cart 10. The support table 13 is used for The supporting table 1 3 lifts the pin (P i η) 1 5 a to the center of the swing arm 14 that clamps the workpiece W together. On the support stand 1 3, the hydraulic cylinder 16 is mounted on the U-shaped clevis 17 fixed to it by a pin 1 5 b. The piston rod 1 of the hydraulic cylinder 16 8 is connected to the clamp rocker arm 1 4 by a pin (pi η) 1 5 c. The clamping rocker arm 14 moves the movable arm 18 forward, that is, moves from the inside of the hydraulic cylinder 16 to the protruding direction, and clamps the workpiece when moving to the predetermined stroke position. FIG. 3 is an enlarged cross-sectional view of the hydraulic cylinder 16 shown in FIG. 2. The hydraulic cylinder 16 is provided with a cylinder block 20 and a terminal mounted on this end.

11433pif.ptd Page 8 200307591 V. Description of the invention (5) End cover 2 1 The cylinder body 2 3 of the rod cover 2 2 installed at the other end. A rod cover 2 2 is attached to the other end of the cylinder block 20 via a brake cylinder 24 and a brake unit brake 25, and the cylinder body 24 and the brake unit brake 25 constitute a cylinder body 2 3. A piston 2 6 that can move back and forth in the axial direction is installed in the cylinder block 20, and the cylinder block 20 is divided into a forward fluid chamber 2 7 a and a backward fluid chamber 2 7 b by the piston 26. . When the piston 26 supplies compressed air to the forward fluid chamber 2 7 a, it moves forward to the rod end cover 2 and moves to the end cover when compressed air is supplied to the backward fluid chamber 2 7 b. cover) 2 1 Move forward. The piston 26 includes a first disk 28 provided with a sealing material 28 a, a second disk 29 having a cylindrical portion 29 a, and an inner peripheral surface of the cylindrical portion 2 9 a of the second disk 29. internal thread. The piston 26 is provided with a ring magnet 3 0 sandwiched between the first disc 28 and the second disc 29, and a sensor (not shown) detects the piston 2 6 by the magnet. s position. In addition, 2 9 b is a wear ring. On the other hand, the piston rod 18 is mounted on the cylinder body 23 supported by the rod cover 2 2 and the brake unit brake 2 5 in the axial direction, as shown in FIG. 2. The cover 2 2 protrudes to the outside and is coupled to the clamping rocker arm 14. In addition, the piston rod 18 is fixed to the piston 26 by screwing an external thread formed on the distal end to an internal screw of the cylindrical portion 29a, and can move in the axial direction integrally with the piston 26.

11433pif.ptd Page 9 200307591 V. Description of the invention (6) Fig. 4A is a half cross-sectional view showing the rod cover 22 shown in Fig. 3, and Fig. 4B is the arrow B-B from the same as Fig. 4A Fig. 4C is a sectional view taken along line C-C of Fig. 4A, and Fig. 4D is a sectional view taken along line D-D of Fig. 4C. As shown in FIG. 4C, three inlet and outlet holes 3 1 are formed in the rod cover 22, and the hoses and piping for inlet and outlet can be connected to any of the inlet and outlet holes according to the use state. The unused inlet and outlet holes 3 1 are closed by the plug 3 1 a, and the used inlet and outlet holes are connected by the flow switching valve through the air pressure source, exhaust hole, hose and piping, and are discharged. The hole 31 is switched to a pressure source and an exhaust hole by a flow switching valve. As shown in FIG. 4C, a guide cylinder 3 2 is installed inside the rod cover 2 2, and a recess communicating with the three inlet and outlet holes 31 is formed on the outer peripheral surface of the guide cylinder 3 2. A groove 3 3 is provided with a throttle hole 3 5 in a communication hole 34 which communicates the concave groove 33 with the inside of the guide cylinder 32. A gas supply channel 2 4 a is formed in the braking cylinder 24, a communication channel 25 a is formed in the brake unit brake 25, and the inside of the guide cylinder 3 2 passes through the gas supply channel 2 4 a and the communication channel 2 5 a. It communicates with the backward fluid chamber 2 7 b. Therefore, each of the drain holes 31 is communicated with the backward fluid chamber 2 7 b through the throttle valve 35. On the other hand, as shown in FIG. 4D, a throttle valve 37 is also provided in the communication flow 36 that communicates the inner end surface of the rod cover 22 with the inside of the guide cylinder 32. As shown in FIG. 3, the three end inlets 2 1 are similarly connected to the advance fluid chambers 2 7 a to the end cover 2 1, respectively.

11433pif.ptd Page 10 200307591 V. Description of the invention (7) Formed, the hose and piping for inlet and outlet can be connected to any inlet and outlet hole according to the use status. The unused inlet and outlet holes 3 8 are closed by the plug 3 8 a, and the used inlet and outlet holes are connected by a pressure switch, a pressure source, an exhaust hole, a hose and a piping through a flow switching valve, and the inlet and outlet holes 3 8 is connected to the air pressure source and the exhaust port by a flow switching valve. A throttle valve similar to the above-mentioned throttle valve is installed between each of the discharge holes 38 and the forward fluid chamber 27a. A braking unit 40, which is a braking device, is installed between the braking unit brake 25 and a rod cover 22 in the braking cylinder 24, and the braking unit 40 is inserted into a sleeve The brake plate 42 in the cylinder 41 is switched to an upright state and an inclined state, and the piston rod 18 can move freely in a combined state and a released state. The sleeve 41 is composed of a main cylinder 4 3 formed in a bottomed cylindrical shape, and a cap 44 fixed to the open end of the main cylinder 43. Caps 4 and 4 are respectively formed with through holes 4 5 and 46 through which the piston rod 18 penetrates. Inside the sleeve 41, a support groove 4 3b formed in the inner peripheral surface of the main cylinder 43 is fitted, and a disc-shaped cover is formed adjacent to the inner surface of the cap 4 4. The plate 4 7 is formed with a through hole 4 7 a through which the piston rod 18 passes through the shaft center of the cover plate 4 7, and both end surfaces thereof are formed perpendicular to the shaft center, respectively. The brake plate 42 is formed in a disc shape that is in flat contact with the inner peripheral surface of the sleeve 41, and is disposed adjacent to the cover plate 47. A brake hole 4 2 a is formed on the shaft center of the brake plate 42 with an inner diameter dimension slightly larger than the outer diameter dimension of the piston rod 18. The piston rod 18 penetrates the brake hole 4 2.

1 1433pi f.ptd Page 11 200307591 V. Description of the invention (8) a. A collar 4 2 b is formed on the outer peripheral surface of the brake plate 4 2 in a predetermined range on the lower side, that is, in the radial direction side, and the collar 4 2 b is connected to the support groove 4 3 b. Therefore, the brake plate 42 can be in an upright state in which one end surface is connected to the end surface of the cover plate 4 7 and the axial direction of the brake hole 4 2 a is aligned with the axial direction of the piston rod 18, and the collar 4 2 b The engaging portion with the support groove 4 3 b serves as a fulcrum, and the cover plate 4 7 is rotated counterclockwise in the figure to tilt toward the bottom wall portion 4 3 a, so that the axial direction of the brake hole 4 2 a is aligned with the axis of the piston rod 18 Freely move between tilted directions. A groove 4 3 c formed on the outer peripheral surface of the main cylinder 4 3 communicates with the cover plate 4 7 and the brake plate 4 2 through a vent hole 4 3 d, and a communication groove 4 3 is formed in the cylinder body 2 4 c and external air inlet and outlet holes 2 4 b. Therefore, the cover plate 4 7 and the brake plate 42 are communicated with the outside, and air can be ventilated when the brake plate 42 moves to the cover plate 4 7. A compression coil spring 4 8 is provided between the cover plate 47 and the brake plate 42 at the upper side in the figure, that is, the other side in the radial direction of the brake plate 42, and the compression coil spring 4 8 is provided on the brake plate 4 An elastic force is applied to 2 toward the bottom wall portion 4 3 a. Therefore, the brake plate 42 uses the elastic force of the compression coil spring to take the joint portion of the collar 4 2 b and the support groove 4 3 b as a fulcrum, and rotates counterclockwise in the figure to tilt it toward the bottom wall portion 4 3 a. The direction is given a rotational force. A brake release pressure chamber 49 is formed between the brake plate 42 and the bottom wall portion 4 3a, and the pressure chamber 49 is communicated with the backward fluid chamber 27b through a through hole 45 formed in the bottom wall portion 4a. That is, the pressure chamber 49 communicates with the inlet / outlet hole 31 through the backward fluid chamber 27b. Therefore, when compressed air is supplied from the inlet and outlet holes 31, the pressure chamber

1 1433pi f.ptd Page 12 200307591 V. Description of the invention (9) 4 9 is supplied with compressed air. When the compressed air is discharged from the inlet and outlet holes 31, the compressed air in the pressure chamber 49 is discharged. The braking unit 40 is in a coupled state by discharging the compressed air in the pressure chamber 49. That is, when the compressed air in the pressure chamber 49 is discharged, the brake plate 42 uses the joint of the collar 4 2 b and the support groove 4 3 b as the fulcrum toward the bottom wall portion 4 by the elastic force of the compression coil spring 48. The 3 a side is inclined into an inclined state, so that the open end portion of the brake hole 4 2 a strongly contacts the outer peripheral surface of the piston rod 18. In this state, when the piston rod 18 is to be moved in the returning direction, that is, in the backward direction, the friction between the brake plate 42 and the piston rod 18 is used to force the brake plate 42 to be bottomed more strongly. The rotational force on the side of the wall portion 4 3 a increases the friction between the brake plate 42 and the piston rod 18, and restricts the backward movement of the piston rod 18. In contrast, when the piston rod 18 is moved forward with the brake plate 42 tilted, the brake plate 42 is resisted from compression by the friction between the brake hole 4 2 a and the piston rod 18. The rotating force in the direction of the coil spring 48 can reduce the friction between the brake plate 42 and the piston rod 18, and the piston rod 18 can freely advance. Thus, the braking unit 40 is engaged with the piston rod 18 only when the piston rod 18 is moved in the backward direction. On the other hand, when compressed air is supplied to the pressure chamber 49, the brake unit 40 is released. That is, when the compressed air is supplied to the pressure chamber 49, the pressure in the pressure chamber 49 increases, and the brake plate 42 resists the compression coil spring 4 8 by the pressure, and is pressed against the cover plate 4 7 in an upright state. . Therefore, formed between the piston rod 18 and the brake hole 4 2 a

11433pi f.ptd Page 13 200307591 V. Description of the invention (ί) The clearance, the piston rod 18 pairs the brake plate 42, that is, the brake unit 40 can move freely. A tapered surface 5 1 is formed on the bottom wall portion 4 3 a of the main cylinder 43 as an inclined surface. The tapered surface 5 1 is connected to the brake unit brake 2 5 to restrict the braking unit 40 from braking in the direction. The unit brake moves in 5 directions. A spring member 5 2 is mounted between the cap 4 4 and the rod cover 2 2. A compression coil spring is used as the spring member 5 2, and the braking unit 40 is provided with the spring member 5. 2 is pressed against the brake unit brake 2 5. A taper lock cylinder 60, which is a load-carrying device, is mounted on the braking cylinder 24. The taper lock cylinder 60 has a rod cover 2 2 and a cylinder. The cylinder body 6 1 integrally formed with the body is equipped with a piston 6 2 that can move freely in the axial direction in the cylinder body. A taper rod 6 3 as a plunger member is integrally formed on the piston 62, and a tip portion of the taper θ 6 3 is formed in contact with the tapered surface 5 1. Conical surface 63a. A spring member 6 5 is inserted between the cover 64 fixed to the cylinder main body 61 and the piston 62. A compression coil spring is used as the spring member 65, and an elastic force in the entering direction is applied to the piston 62 by the spring member 65. Therefore, the taper rod 6 is pushed by the spring member 65 to enter the tapered surface 51 formed on the rear end surface of the brake unit 40. When the taper rod 6 3 enters, the taper surface 6 3 a of the taper rod 6 3 is in contact with the taper surface 5 1 of the braking unit 40, and is on the braking unit 40.

11433pif.ptd Page 14 200307591 V. Description of the invention (11) The load is taken as the forward direction, that is, the rod cover 2 2 direction. The braking unit 40 can resist the elastic force of the spring member 5 2 to the rod end cover (rod) within the range of the stroke S a between the cap and the rod cover 2 2 by the load. cover) 2 2 side movement, and the stop position is determined by the piston rod 18 according to the reaction force from the workpiece W applied to the braking unit 40. The tapered surface 6 3 a forms an acute angle to the axis of the tapered rod (taperr 〇) 6 3, and the tapered surface 51 forms a pure angle to the shaft center of the braking unit 40, so it is added by the spring member 6 5 The tapered rod (taperr 〇d) 63 is increased in strength to be transmitted as a load on the braking unit 40, and the tapered rod (taperr 〇d) is not caused by the load from the braking unit 40 side. ) 6 3 Move backward. In order for the tapered rod 6 3 to move backward against the elastic force, a communication passage 6 6 branched from the gas supply passage 2 4 a is formed on the cylinder body 6 1, and the communication passage 66 and the taper latch (taper 1 〇) are formed. ck) The fluid chamber 67 in the cylinder 60 communicates. Therefore, when the compressed air is supplied from the inlet / outlet hole 31, the compressed air is caused to flow into the fluid chamber 67 through the communication passage 66, and the tapered rod (t a p r r 〇 d) 6 3 and the piston 6 2 move backward. The pressure in the fluid chamber 6 7 required for the tapered rod 6 3 to move backward is set to be smaller than the pressure chamber 4 required in the braking unit 40 to make the brake plate 4 2 stand upright. 9 pressure. When compressed air is supplied from the inlet / outlet hole 31, the tapered rod (taperr 0d) 63 is retracted before the brake plate 42 becomes upright, and when compressed air is discharged from the inlet / outlet hole 31, the tapered rod (Taper

11433pi f.ptd Page 15 200307591 V. Description of the invention (12) r 〇 d) 6 3 Brake unit 40 enters the front brake plate 4 2 and tilts. 5A to 5C are schematic explanatory diagrams showing the operation of the brake unit 40 and the taper lock cylinder 60. First, in a state where the piston 26 is in the backward end position, when the compressed air is supplied from the inlet / outlet hole 38 to the forward fluid chamber 27a, the piston 26 and the piston rod 18 are fixed to the positions shown in FIG. 5A. The stroke position is the position where the clamping rocker arm 14 clamps the workpiece W forward. This stroke position is used as the position of the stroke Sa of the braking unit 40, which is only a predetermined stroke backward from the forward end position of the piston 26. When the piston 26 moves forward, a negative pressure is generated in the backward fluid chamber 2 7 b, the pressure chamber 49, and the fluid chamber 67, and the brake plate 42 is upright, that is, the brake unit 40 by the negative pressure. It is in a released state, and a taper rod 6 3 is used as a retracted position. When the piston 26 reaches the predetermined stroke position, the negative pressure in the pressure chamber 49 and the fluid chamber 67 gradually decreases, as shown in FIG. 5B. First, the brake plate 42 is only inclined at an angle α, and the brake unit 40% In the coupled state, the braking unit 40 of the piston rod 18 is restricted from moving in the backward direction. At this time, when it becomes the stroke position of the clamping rocker arm 14 to clamp the workpiece W, the piston rod 18 switches the braking unit 40 to the coupled state, but the braking unit 40 may not be limited to the stroke of the piston rod 18 Position to the piston rod 18 in a coupled state. Therefore, even when the stroke position of the piston rod 18 when being clamped by deformation of the work W or the like changes, the braking unit 40 can reliably be coupled to the piston rod 18. When the negative pressure in the fluid chamber 67 decreases again from this state, as shown in the figure

11433pi f.ptd Page 16 200307591 V. Description of the invention (13) As shown in 5C, the taper rod 6 3 moves toward the tapered surface 51 of the braking unit 40. Then, the tapered rod (taperr 0d) 6 3 enters the movement, that is, the elastic force applied to the taper rod 6 3 passes through the tapered surface 6 3 a and the tapered surface 5 1, and is transformed into the braking unit 4. 0 Loads in the forward direction. In this state, when the compressed air in the forward fluid chamber 2 7 a is discharged to the outside, no load is applied to the piston rod 18 due to the pressure in the forward fluid chamber 2 7 a. The spring force of the spring member 65 is applied to the taper rod 63, so it enters the braking unit 40 regardless of the stop of the supply of compressed air. Therefore, the piston rod 18 restricts the combined state with the braking unit, that is, the backward movement of the braking unit, and the braking unit 40 is loaded in the forward direction by a taper rod 63, so despite the forward movement The compressed air in the fluid chamber 27a is exhausted to the outside, but the piston rod 18 is still loaded in the forward direction by the brake unit 40 and the taper rod 63. That is, even if the hydraulic cylinder 16 stops supplying compressed air to the forward fluid chamber 2 7 a and exhausts the internal air to the outside, the piston rod 18 can be applied with a tapered rod from the braking unit 40. (taper rod) 6 3 weight. In order to supply compressed air to the hydraulic cylinder 16, as shown in FIG. 2, the inlet and outlet joints 70 provided on the conveying trolley 10 are connected with the inlet and outlet holes 31 and the inlet and outlet hoses 7 1 a and The discharge hole 3 8 is followed by the inlet and outlet holes 7 1 b to supply and discharge compressed air from the forward fluid chamber 2 7 a and the backward fluid chamber 2 7 b.

1 1433pi f.ptd Page 17 200307591 V. Description of the invention (14) It is carried out with a row of 70 joints. On the other hand, in the first workbench S 1 shown in FIG. 1, an inlet / outlet joint 7 2 is provided adjacent to the conveyance trolley 10, and an inlet / outlet hose connected to the inlet / outlet joint 7 2 is connected to the valve through a flow switching valve. The air pressure source shown. These inlet and outlet joints 7 0 and 7 2 are connected to each other when the transfer cart 10 is at the initial position of the table, and can be supplied to the fluid chambers 2 7 a and 2 7 b from an air pressure source provided outside the transfer cart 10, respectively. Compress the air and exhaust the air in the fluid chambers 2 a and 2 b to the outside. With this, after the workpiece W is carried into the workpiece support table 13 with the clamping rocker arm 14 released, the workpiece W can be connected by closing the clamping rocker arm 14 with a hydraulic cylinder 16. In this way, by moving the transfer cart 10 while the workpiece W is connected, the transfer cart can perform a predetermined assembly operation on each table constituting the vehicle body assembly line. In the final table S η shown in FIG. 1, in order to supply compressed air to the backward fluid chamber 27, an inlet / outlet joint 7 2 a connected to the inlet / outlet joint 70 on the trolley side is provided. By releasing the clamping rocker arm 14, the workpiece W after the predetermined assembly is completed can be carried out of the production line. Next, the clamp sequence of the workpiece W using the clamp device 12 of the hydraulic cylinder 16 described above will be described. In order to move the piston rod 18 back, the clamping rocker arm 1 4 is released, and the inlet and outlet joints 7 are passed. 0 and 7 2 supply compressed air to the backward fluid chamber 2 7 b. In this state, the piston 26 becomes the backward end position, the piston rod 18 also becomes the backward end position, and the swing arm 14 can be released to carry the workpiece W. Moreover, the brake slip

11433pif.ptd Page 18 200307591 V. Description of the invention (15) The element 40 is released into a state that allows the piston rod 18 to move freely in the axial direction, and the tapered rod (taperr 〇d) 6 3 becomes a backward state so that the brake unit 4 〇 By the spring member 52, the brake unit brake 5 is brought into a state. To close the clamping rocker arm 1 4, the forward fluid chamber 27 is supplied with compressed air through the inlet and outlet holes 38. Thereby, the piston 26 and the piston rod 18 are moved forward, and when the piston 26 and the piston rod 18 are moved to a predetermined stroke position, the clamp rocker arm 14 is closed. When the clamping rocker arm is closed, as shown in FIG. 5B, the brake plate 42 is tilted, the brake unit 40 is switched to the engaged state, and the backward movement of the piston rod 18 is restricted. When the backward movement of the piston rod 18 is restricted by the braking unit 40, as shown in FIG. 5C, the tapered rod (taperr 0d) 63 is moved into the tapered surface 51 of the braking unit 40. . Then, the tapered surface 6 3 a of the tapered rod 6 3 is connected to the tapered surface 5 1 of the braking unit 40, and a load in the forward direction is applied to the braking unit 40. The piston rod 18 restricts the backward movement of the braking unit 40, so when a load in the forward direction is applied to the braking unit 40, its load is also added to the piston rod 18. When a gap is generated between the clamp rocker arm 14 and the workpiece W by vibration or the like, the piston rod 18 and the brake unit 4 are loaded by using a load applied by a taper rod 63. 0 is integrally moved to the rod end cover (r dcdc ver) 2 2 side. In this state, when the compressed air in the forward fluid chamber 2 7 a is discharged to the outside, no load is applied to the piston rod 18 by the pressure in the forward fluid chamber 2 7 a. (Taper rod) 6 3 is given the spring force of the spring member 65, so the load on the braking unit 40 is maintained.

11433pif.ptd Page 19, 200307591 V. Description of the invention (16) The load in the forward direction is applied to the piston rod 18 by the braking unit 40, and it is clamped by the vibration and the like accompanying the movement of the trolley. When a looseness occurs between the rocker arm 14 and the workpiece W, the piston rod 18 and the braking unit 40 will move forward together to absorb the looseness. Therefore, when the workpiece W is clamped as shown in FIG. 2 by the clamp rocker arm 14 connected to the hydraulic cylinder 16, even if the supply of compressed air to the forward fluid chamber 2 7 a is stopped and the internal The air is discharged to the outside, and a load on the clamping rocker arm 14 can be used to hold the workpiece W. In this way, when the workpiece W clamped by the clamping rocker arm 14 is transferred by the transfer carriage 10, the inlet / outlet joint 72 is removed from the inlet / outlet joint 70 on the carriage side. Since each of the fluid chambers 27a, 2b is opened to the atmosphere after being removed, the air supplied to the forward fluid chamber 27a is exhausted to the outside. Thereby, the clamping force applied to the piston rod 18 by the piston 26 disappears, but a load from the taper rod 63 is applied to the piston rod 18 by the braking unit 40. Therefore, even if the transmission trolley 10 is subjected to vibration and impact during the transportation of the transfer trolley 10, the connection force of the clamping rocker arm 14 to the workpiece W will not be loosened ', and the workpiece W can be reliably held. In order to remove the work W at the final table S η, when the compressed air is supplied to the backward fluid chamber 2 7b, the tapered rod 6 3 and the piston 6 are first raised by the pressure in the fluid chamber 67. 2 — The starting movement moves backward, and the tapered surface 6 3 a of the tapered rod 6 3 is removed from the tapered surface 51 of the braking unit 40. Next, the brake unit 40 is moved to the brake unit brake 25 by the spring member 52.

11433pif.ptd Page 20 200307591 V. Description of Invention (17). By continuing to supply the compressed air in the backward fluid chamber 2 7 b, the pressure in the pressure chamber 49 is increased and the brake plate 42 is placed in an upright state, that is, the brake unit 40 is released, and the piston rod 18 and The piston 2 6 moves back and forth, and the clamping rocker arm 14 is released. When returning the transfer carriage 10 with the workpiece W removed, to the original table, if the closed swing arm 14 is set, the forward fluid chamber 27a is supplied with compressed air and the piston The lever 18 moves forward. Fig. 6 is an enlarged front view showing other types of clamp devices. In Fig. 6, the same components as those shown in Fig. 2 are marked with the same symbols. The clamp device 12 shown in FIG. 2 moves the clamping rocker arm 14 by the forward movement, that is, the squeeze movement, of the piston rod 18. In contrast, in the clamp device 12 a shown in FIG. 6, The backward movement of the piston rod 18, that is, the drag movement, causes the clamp rocker arm 14 to be connected. In the hydraulic cylinder 16a for performing such a clamping operation, a brake cylinder 24 is provided at the rear end of the cylinder main body 23, and a brake unit 40 is installed inside the brake cylinder 24. The movement of the return direction of the piston rod 18, that is, the forward direction of the piston rod 18 is restricted. Then, the tapered rod (t ape r r 〇 d) applies a load in the backward direction to the braking unit 4 〇. In this way, the hydraulic cylinder 16a shown in FIG. 6 closes the clamping rocker arm 14 by moving the piston rod 18 backward, and the clamping rocker arm 14 can be closed in the same manner as the embodiment described above. A negative in the reverse direction is applied to the piston rod 18.

11433pif.ptd Page 21 200307591 V. Description of the invention (18) The present invention is not limited to the embodiments described above, and can be modified in various ways without departing from the scope of the invention. For example, the hydraulic cylinders 16 and 16a are used to clamp the panel material constituting the vehicle body, but the invention is not limited to this. When the piston rod 18 is used as the predetermined stroke position, When a predetermined load can be applied to the piston rod 18 by supplying hydraulic pressure to the piston 26, the hydraulic cylinder can be applied to any application. This hydraulic cylinder moves the piston 26 by compressed air, but the piston 26 can also be moved back and forth by the pressure of a liquid such as oil pressure. This hydraulic cylinder is used to drive the clamp device 12 provided on the transfer cart 10, but it is also applicable to the case where it is mounted on the top end of a robotic rocker and clamps the panel material for transfer. This hydraulic cylinder employs a braking unit 40 that is coupled to the piston rod 18 by tilting the brake plate 42 as a braking device, but is not limited to this. For example, a brake unit that is limited to the axial direction by support by a bracket may be used The plurality of steel balls that are in contact with the outer peripheral surface of the piston rod 18 at the same time, and the inner peripheral surface that is in contact with these steel balls form a tapered shape, and have a cover with an inclined surface at the end. d) 6 3 pairs of inclined surfaces enter and move the cover in the axial direction to join the piston rod 18 in a combined state. In addition, a brake metal may be provided in the braking cylinder to cover the piston rod 18, and the brake metal may be pressed against the piston rod 18 to face the piston rod 1. 8 into a combined state. According to the present invention, when the piston is moved to a predetermined stroke position

11433pi f.ptd Page 22 200307591 V. In the description of the invention (19), the return movement of the piston is restricted by the braking device, and the load on the braking device is loaded in the forward direction or the backward direction by the load loading device. Therefore, even if the hydraulic pressure supplied to the hydraulic chamber is discharged in order to move the piston, the piston rod can still be loaded by the braking device. Therefore, even if the fluid in the hydraulic chamber is discharged, a predetermined load can be applied to the driven member through the piston rod. The braking device can restrict the return movement of the piston rod at any stroke position, so a stable load can always be applied to the piston rod regardless of its stroke position. When a hydraulic cylinder is mounted on a transfer trolley to drive the clamping rocker arm, even when the supply of hydraulic pressure is stopped while the conveying trolley is moving, the clamping rocker arm can be reliably loaded with a load from the piston rod.

11433pif.ptd Page 23, 200307591 Simple illustration of the drawing [Simplified illustration of the drawing] FIG. 1 is a plan view showing a part of an assembly line of an automobile body constituting a panel material constituting the automobile body by conveying a trolley. FIG. 2 is a diagram 1 is an enlarged front view of the clamp device shown in FIG. 3; FIG. 3 is an enlarged sectional view showing the hydraulic cylinder shown in FIG. 2; FIG. 4A is a rod end cover (r0dc〇ver) shown in FIG. 3; 2 A half-section view of 2 FIG. 4B is a side view viewed from the direction of the arrow B-B line in FIG. 4A. FIG. 4C is a cross-sectional view along line C-C in FIG. 4A. 4C is a cross-sectional view taken along line D-D. Fig. 5 A 5C shows the outline of the operation of the brake unit and the taper latch (tape r 1 〇ck). Fig. 6 shows other types of An enlarged front view of the clamp device Ming) 1 0 • Conveying cart 5 1 1 • Wheels 1 2, 1 2 a ·· Clamping device 1 3 • Work support table 1 4 • Tightening swing arm 1 5 a 1 5 C • Pin 1 6 1 6 a; Hydraulic cylinder 1 1 7 U-clamp (c 1 ev is) 1 8 Piston rod 2 〇 Cylinder block 2 1 End cover (e η dc〇ver:) 5

11433pif.ptd Page 24 200307591 Brief description of the drawings 2 2 ·· Rod end cover (r 〇d cover) 2 3 ·· Cylinder body, 2 4 • Brake cylinder 2 4 a • Gas supply channel, 2 4 b inlet Exhaust hole 2 5 • Brake unit brake, 2 5 a ·· Communication path 2 6 • Piston, 2 7 a • Forward fluid chamber, 2 7 b ·· Reverse fluid chamber, 2 8 ·· 1st disc j 2 8 a Sealing material 2 9 • 2nd disc> 2 9 a Cylindrical part 2 9 b Wear ring 1 3 0: Magnet, 3 1: Inlet / outlet hole, 3 1 a: Plug, 3 2: Guide tube Body, 3 3: groove, 3 4: communication hole, 3 5: throttle L, 3 6: communication flow, 3 7: throttle,

11433pif.ptd Page 25 200307591

Brief description of the drawing 3 8 * inlet and outlet holes 3 8 a • plug 5 4 0 brake unit '4 1 sleeve 4 2 brake plate, 4 2 a • brake hole, 4 2 b ·· collar 4 3: main cylinder 4) a • bottom wall, 4 5 b: support groove, 4 ·] c · groove, 4 5 d • ventilation 孑 L, 4 4: cap, 4 5, .4 6 : Through, 4 7:: cover j 4 7 a: through hole 4 8 compression coil spring, 4 9 brake release pressure chamber, 5 1 tapered surface j 5 2 spring member j 6 0 taper lock 6 1 cylinder body j 6 2 piston y 6 3 conical rod (ta per rod), cylinder, 11433pi f.ptd 200307591

11433pi f.ptd Page 27

Claims (1)

200307591 6. Scope of patent application1. A hydraulic cylinder, characterized in that it includes: a cylinder body with a cylinder body with an end cover at one end and a rod cover at one end; a piston at The cylinder body is freely installed to move back and forth in the axial direction, and is divided into a forward fluid chamber and a backward fluid chamber; a piston rod is installed on the cylinder body to move back and forth in the axial direction, and is fixed to the piston. Protruding from the rod end cover to the outside; a braking device is provided to move freely in a combined state and a released state with respect to the piston rod, and limits the piston rod when the piston rod moves to a predetermined position A return movement; and a load-loading device, comprising: a plunger (p 1 unger) member provided freely to move forward and backward toward the braking device; and a spring-loaded spring that applies the plunger member in the forward and backward directions.篑 member, and a load in the forward or reverse direction is applied to the braking device, wherein when the braking device becomes In the coupled state, even if the fluid in the fluid chamber is discharged, a load is applied to the piston rod through the braking device by the load loading device. 2. The hydraulic cylinder according to item 1 of the scope of patent application, characterized in that the plunger (p 1 u n g e r) member is provided to move forward and backward freely toward an inclined surface formed on the braking device. 3. The hydraulic cylinder according to item 1 or item 2 of the scope of patent application, characterized in that the brake device is formed by tilting a brake plate having a brake hole penetrated by the piston rod to the piston rod. Combine 11433pif.ptd Page 28 200307591 6. Scope of Patent Application Status. 4. A clamp device, comprising: a cylinder body having a cylinder body having an end cover at one end and a rod cover at one end; a piston in the cylinder body It is installed freely back and forth along the axial direction, and is divided into a forward fluid chamber and a backward fluid chamber; a piston rod is installed on the cylinder body to move back and forth in the axial direction, and is fixed to the piston while being fixed from the rod end. A rod cover protrudes to the outside; a clamping rocker arm connected to the piston rod to clamp the workpiece by the forward or backward movement of the piston rod; a braking device which is coupled to the piston rod in a combined state and The release state can be set freely, and when the piston rod is moved to a predetermined position, the return movement of the piston rod is restricted; and a load-loading device having a plunger which is freely moved forward and backward toward the braking device ( p 1 unger) member, and a spring member that applies elastic force to the plunger member in the in-out direction, and is mounted on the brake device. Place the load in the forward or backward direction, and when the brake device becomes the coupled state, even if the fluid in the fluid chamber is discharged, the load is applied to the piston rod through the brake device through the load device. 5. The pliers device according to item 4 of the scope of patent application, characterized in that the plunger (p 1 u n g e r) member is arranged to move forward and backward freely toward an inclined surface formed on the braking device. 11433pif.ptd Page 29, 200307591 6. Scope of patent application6. The clamp device described in item 4 or 5 of the scope of patent application, characterized in that the brake is provided by a brake hole having a piston hole penetrating through The plate is inclined to the piston rod, so that the braking device is in a coupled state. 11433pif.ptd Page 30