JP2020060271A - Hydraulic cylinder with tuning function and hydraulic device using the hydraulic cylinder - Google Patents

Abstract

To provide a hydraulic cylinder with a tuning function which does not require a complicated hydraulic circuit.SOLUTION: In a hydraulic 100 attached to a piston 11 to a cylinder tube 1 so as to project from and retract into the cylinder tube 1, a cylindrical spool 30 is slidably provided in the piston rod 11, and a resilient member 50 pressing the spool 30 in a pressure oil chamber 10 direction is provided. A partition wall 34 having a decompression hole 35 is provided in the spool 30. A pressure oil inflow path H1 is provided between an inflow port 6 of pressure oil Y provided in the cylinder tube 1 and one space 36 of the partition wall 34, and a pressure oil channel H3 is provided between the other space 33 of the partition wall 34 and the pressure oil chamber 10. A logic valve 20 is provided between the pressure oil chamber 10 and a discharge port 7 of the cylinder tube 1. The pressure oil Y is supplied into an inflow port and the logic valve 20 at the time of normal operation. The discharge port 7 is connected to a tank 140, and the inflow port, the logic valve 20, and the discharge port 7 are connected to the tank 140 at the time of reverse operation.SELECTED DRAWING: Figure 1

Description

  INDUSTRIAL APPLICABILITY The present invention is used for an industrial machine that requires synchronized operation of a large number of hydraulic cylinders (for example, a jack-up system of a precision machine or a large molding press that molds a molded product while synchronizing a plurality of hydraulic cylinders). The present invention relates to a hydraulic cylinder with a tuning function, and a hydraulic device using a large number of the hydraulic cylinders.

In a jack-up system of a precision machine or an industrial machine such as a large molding press, it is necessary to operate a plurality of hydraulic cylinders while synchronizing them. As an example of such a device, there is a device as disclosed in Patent Document 1.
This device is a speed adjusting device for a multi-cylinder type press that can perform synchronous movement of the hydraulic speeds of a plurality of hydraulic cylinders of the same standard in a reliable manner to move the press members in parallel.

  This device is provided with at least two hydraulic cylinders having the same specifications, a synchronizing valve is provided in the hydraulic circuit, and rod side chambers of both hydraulic cylinders are connected to the outlet port of the flow dividing valve. By doing so, the pressure oil is divided into equal parts in the hydraulic circuit before the pressure oil reaches the two hydraulic cylinders, and the divided pressure oil is supplied to the two hydraulic cylinders. By doing so, these are synchronized and operated. With such a configuration, when the rod of the first hydraulic cylinder strokes by Δs, the rod of the second hydraulic cylinder also strokes by Δs at the same speed as the first hydraulic cylinder. The tuned valve is also required to have a difference in load between the left and right of 20% or less, which is not convenient to use.

JP, 2007-144455, A

  However, in such a conventional tuning device, since the flow dividing valve corresponds to two hydraulic cylinders, if the number of hydraulic cylinders is four, two flow dividing valves are required. If the number increases, a diversion valve will be required in proportion to this. Then, the hydraulic circuit becomes complicated accordingly, and the tuning accuracy also decreases. If the tuning accuracy decreases, the protrusion speed and timing of the piston rod will shift, and the protruding end of the piston rod will become uneven, and as a result, distortion will occur in each part of the molded product that is pressed by these hydraulic cylinders. It causes defective products.

  In addition, when the molded product becomes large, its shape and unevenness change significantly. In such a case, the shape of each part pressed by each hydraulic cylinder may be variously changed, and the required pressing force may be different for each part, or a hydraulic cylinder not required may be generated depending on the shape. When using a large number of hydraulic cylinders at the same time, it is necessary to flexibly deal with such changes.

  In the conventional industrial machine as described above, if several tens of hydraulic cylinders are synchronized with high precision, servo control or complicated closed circuit control using a solenoid proportional valve is required, which is expensive in cost. Not only will it become a big thing, but its installation space will also become large. Therefore, there has long been a demand for a hydraulic cylinder that does not require such a complicated hydraulic circuit.

  The first object of the present invention is to provide a hydraulic cylinder with a tuning function that can be adapted to such advanced use conditions in the conventional example and does not require a complicated hydraulic circuit. A second object is to provide a hydraulic device using a hydraulic cylinder.

The invention according to claim 1 (hydraulic cylinder with tuning function 100 (hereinafter, also simply referred to as hydraulic cylinder in this specification): FIGS. 1 to 7) is
A cylinder tube 1 having a pressure oil Y inflow port 6 and a discharge port 7;
A piston rod 11 that is housed so as to be retractable from the rod-side end surface (one end surface) of the cylinder tube 1, and has a storage space 12 that extends in the axial direction formed therein.
It is provided between a bottom 1s of a piston housing hole 1h formed in the cylinder tube 1 and housing the piston rod 11, and a rod insertion end 11a of the piston rod 11, and the piston rod is introduced by the inflow of pressure oil Y. A pressure oil chamber 10 for pushing out 11,
A pressure oil discharge path H2 connected from the pressure oil chamber 10 to the discharge port 7,
A cylindrical spool 30 disposed on the head side (the other end side) in the storage space 12 and slidably inserted into the storage space 12;
An elastic member 50 that is disposed on the rod side (one end side) in the storage space 12 and presses the spool 30 toward the hole bottom 1s side of the piston storage hole 1h,
A partition wall 34 provided in the spool 30 and provided with a pressure reducing hole 35;
A pressure oil inflow passage H1 extending from the inflow port 6 to the front of the partition wall 34;
The pressure oil passage H3 extends from the back of the partition wall 34 to the pressure oil chamber 10.

  According to this, the differential pressure ΔP between the pressures P2 and P3 generated before and after the partition wall 34 can be kept constant by the action of the elastic member 50 and the spool 30 during the simultaneous operation of the multiple hydraulic cylinders 100. Even if the load F applied to the piston rods 11 of the respective hydraulic cylinders 100 is different, or the load F fluctuates during the protrusion, the load F applied to any one or a plurality of piston rods 11 becomes zero, and the remaining Even if the load F is applied to the piston rods 11, the projecting operation of all the piston rods 11 can be continued in synchronization with each other at the same speed and the same timing.

  According to a second aspect of the present invention, in the hydraulic cylinder 100 with a tuning function according to the first aspect (FIGS. 3 and 4), the pressure reducing hole 35 of the partition wall 34 is aligned with the pressure reducing hole 35. An opening adjustment pin member 40 for adjusting the opening of the valve 35 is provided in the piston rod 11.

  According to this, when the opening adjustment pin member 40 is brought close to the decompression hole 35 to limit the opening thereof, the pressure flowing through the decompression hole 35, the pressure oil passage H3, and the pressure oil chamber 10 is reduced. Since the amount of the oil Y is suppressed, the projecting operation of the piston rod 11 can be delayed as compared with the case where the pressure reducing hole 35 is fully opened. When a large number of hydraulic cylinders 100 are used, the movement of each hydraulic cylinder 100 can be individually fine-tuned and facilitated to be synchronized, even if there is a minute machine difference due to, for example, machining tolerance.

  According to a third aspect of the present invention, in the hydraulic cylinder 100 with a tuning function according to the first or second aspect (FIGS. 3 and 4), the hollow sleeve 19 that opens and closes the pressure oil passage H3 provided on the downstream side of the partition wall 34, It is characterized in that it is provided in the piston rod 11.

  According to this, when the pressure oil passage H3 is closed by the hollow sleeve 19, the pressure oil Y is cut off here, and the piston rod 11 does not operate. When a large number of hydraulic cylinders 100 are used in synchronization, it is possible to operate only the necessary hydraulic cylinders 100 and suspend the unnecessary hydraulic cylinders 100.

  According to a fourth aspect, in the hydraulic cylinder 100 with a tuning function according to the second or third aspect, the opening adjustment pin member 40 and the hollow sleeve 19 are coaxially arranged, and the opening adjustment pin member 40 and the hollow sleeve 19 are operated. It is characterized in that the portions 41 and 19a are exposed at the rod-side end surface of the piston rod 11.

  Thus, when the operation of the opening adjustment pin member 40 and the hollow sleeve 19 is performed on the rod side of the piston rod 11, that is, when the hydraulic cylinder 100 is installed on the base 110, the opening adjustment pin is operated from the upper surface side of the base 110. It is possible to adjust the member 40 and the hollow sleeve 19.

  A fifth aspect of the present invention is characterized in that, in the hydraulic cylinder 100 with a tuning function according to any of the first to fourth aspects, the pressure reducing hole 35 is a thin blade orifice hole.

  When the hydraulic device is operated, the temperature of the pressure oil Y gradually rises and its properties change. On the other hand, by forming the pressure reducing hole 35 as a thin blade orifice hole, the temperature compensation function can be given to the hydraulic cylinder 100 with a tuning function, and the influence of the temperature rise of the pressure oil Y on the rising speed of the piston rod 11 can be eliminated. Can be done.

According to a sixth aspect, in the hydraulic cylinder 100 with a tuning function according to any one of the first to fifth aspects, a logic valve 20 installed in the pressure oil discharge passage H2 is further added,
The logic valve 20 is connected to the valve body 21 for opening and closing the pressure oil discharge passage H2 and the pipe 200 connected to the inflow port 6 during the protrusion work of the piston rod 11, and the protrusion work of the piston rod 11 is completed. And a pilot port 29 connected to a tank 140 for circulating the pressure oil Y.
Since the valve spring 23 is not indispensable, a valve spring 23 having a weak elastic force to the extent that the opening / closing valve body 21 is lifted is further provided so as to press in the normally closed direction of the pressure oil discharge passage H2. May be.

A seventh aspect of the present invention is a first hydraulic device (FIG. 8) in which a large number of hydraulic cylinders 100 with a tuning function according to the sixth aspect are used for synchronization.
The hydraulic cylinders 100 with a plurality of tuning functions according to claim 6, which are installed on the base 110 such that the piston rods 11 project from and retract into the base 110 of the mechanical equipment M.
A hydraulic pump 130 for sending pressure oil Y to the hydraulic cylinder 100 with the tuning function;
A tank 140 for collecting the pressure oil Y from the hydraulic cylinder 100 with the tuning function,
It has ports P, A, E, and B for switching the supply direction of the pressure oil Y from the hydraulic pump 130 and the return direction of the pressure oil Y to the tank 140, and when the piston rod 11 is projected, A direction switching valve 150 that connects the PA port and the EB port, and connects the PB port and the EA port when the piston rod 11 is retracted,
A main pipe 200 that connects the hydraulic pump 130 and the inflow port 6 of the hydraulic cylinder 100 with the tuning function;
A pilot pipe 210 branched from the main pipe 200 and connected to the P port, and connected from the A port to the pilot port 29 of the logic valve 20;
A discharge pipe 220 that connects the discharge port 7 of the hydraulic cylinder 100 with a tuning function and the tank 140,
Loop piping 230 connecting the B port and the E port,
It is characterized by being constituted by a connection pipe 240 connecting the loop pipe 230 and the discharge pipe 220.

An eighth aspect of the present invention is a second hydraulic device (FIG. 9) in which a large number of hydraulic cylinders 100 with a tuning function according to the sixth aspect are used for synchronization.
The hydraulic cylinders 100 with a plurality of tuning functions according to claim 6, which are installed on the base 110 such that the piston rods 11 project from and retract into the base 110 of the mechanical equipment M.
A hydraulic pump 130 for sending pressure oil Y to the hydraulic cylinder 100 with the tuning function;
A tank 140 for collecting the pressure oil Y from the hydraulic cylinder 100 with the tuning function,
It has ports P, A, E, and B for switching the supply direction of the pressure oil Y from the hydraulic pump 130 and the return direction of the pressure oil Y to the tank 140, and when the piston rod 11 is projected, A direction switching valve 150 that connects the PA port and the EB port, and connects the PB port and the EA port when the piston rod 11 is retracted;
A main pipe 200 connecting the hydraulic pump 130 and the P port, and connecting the A port and the inflow port 6 of the hydraulic cylinder 100 with the tuning function;
A pilot pipe 210 that branches from the main pipe 200 and is connected to the pilot port 29 of the logic valve 20 on the downstream side of the A port;
A discharge pipe 220 that connects the discharge port 7 of the hydraulic cylinder 100 with a tuning function and the tank 140,
Loop piping 230 connecting the B port and the E port,
It is characterized by being constituted by a connection pipe 240 connecting the loop pipe 230 and the discharge pipe 220.

  According to a ninth aspect of the present invention, in the hydraulic system according to the seventh or eighth aspect, instead of the loop pipe 230, a B port pipe 231 for discharging the pressure oil Y from the B port to the tank 140 is provided, and the connection pipe 240 is connected to the E port. It is characterized by being connected to a port (Fig. 10).

  The hydraulic cylinder 100 of the present invention operates in synchronization regardless of load fluctuations (including zero load). When this is applied to the hydraulic device and the pressure oil Y having the same pressure P1 is supplied from the main pipe 200 to the inflow ports 6 of all the hydraulic cylinders 100, during the forward operation of the hydraulic cylinders 100 (protruding operation of the piston rod 11), It works in synchronism all at once without a complicated hydraulic circuit as in the past. In other words, it rises all at once at the same speed. As a result, no distortion occurs in the molded product that is ejected.

1 is a cross-sectional view of a first embodiment of a hydraulic cylinder with a tuning function of the present invention mounted on mechanical equipment. FIG. 2 is a cross-sectional view during operation in the extrusion direction in FIG. 1. 1A is an enlarged partial sectional view of the spool portion in FIG. 1, FIG. 1B is an enlarged partial sectional view showing the positional relationship between the spool side oil passage port and the rod side oil passage port before operation, and FIG. 2D is an enlarged partial cross-sectional view showing the positional relationship between the spool-side oil passage port and the rod-side oil passage port immediately after operation, (d) in FIG. 1, the spool-side oil passage port and the rod-side oil passage port when the piston rod is projected It is an expanded partial sectional view showing a positional relationship. FIG. 4 is an enlarged partial sectional view around the pressure reducing hole in FIG. 3. FIG. 2 is a sectional view when the piston rod is lifted to the top dead center in FIG. 1. FIG. 6 is a cross-sectional view showing a state where the load is removed and the piston rod is switched to descend in FIG. 5. It is a top view of FIG. It is a 1st hydraulic circuit diagram of the hydraulic system of the mechanical equipment which mounted many hydraulic cylinders with a tuning function of this invention. It is a 2nd hydraulic circuit diagram of this invention. It is a 3rd circuit diagram which provided B port piping instead of the loop piping of the hydraulic circuit of this invention, and connected the connection piping to E port.

A first embodiment (FIGS. 1 to 7) of a hydraulic cylinder 100 with a tuning function of the present invention will be described below with reference to the drawings. 8 and 9 are first and second hydraulic circuit diagrams of a hydraulic system for operating a number of hydraulic cylinders 100 with a tuning function of the present invention in synchronization, and FIG. 10 is a modification thereof.
The hydraulic cylinder 100 with a tuning function of the present invention includes a cylinder tube 1, a piston rod 11, a spool 30, and a logic valve 20, which are main components.

The cylinder tube 1 includes a cylindrical tube body 1a, a ring-shaped rod cover 1b fitted on the inner surface of the upper end portion of the tube body 1a via an O-ring, a head cover 1c provided outside the lower end portion, and if necessary. And a flange 1d provided by being screwed onto the outer circumference of the tube body 1a.
The rod cover 1b is sandwiched and fixed between the inner flange of the flange 1d and the step portion formed on the inner circumference of the tube body 1a. An O-ring is fitted between the two.
The rod cover 1b is provided with the sliding hole 2 for the piston rod 11, and has a ring shape as described above. An O-ring slidably contacting the piston rod 11 and an oil seal are attached to the inner peripheral surface of the sliding hole 2 so that the piston rod 11 is aligned with the central axis of the tube body 1a and extends from the rod cover 1b in the retracted direction. Mounted to move. In this embodiment, when the piston rod 11 is immersed in the tube body 1a, the upper surfaces of both are flush with each other (FIG. 1).

  The inner diameter of the tube body 1a is larger than the inner diameter of the sliding hole 2 of the rod cover 1b, and a first gap 3 through which the pressure oil Y flows is formed between the inner diameter of the tube body 1a and the outer peripheral surface of the piston rod 11. The first gap 3 is provided on the entire inner circumference of the tube body 1a from the rod cover 1b to the head cover 1c in a range exceeding the stroke of the piston rod 11. An inflow port 6 for the pressure oil Y is formed in the tube body 1a on the rod cover 1b side and communicates with the upper end of the first gap 3. A rod-side oil passage hole 11b is formed at the lower end of the first gap 3 so as to penetrate from the outer peripheral surface of the piston rod 11 to the inner peripheral surface thereof. The distance from the rod-side oil passage hole 11b to the inflow port 6 (to be precise, the piston rod 11 rises from the stop point of the rod-side oil passage hole 11b when the piston rod 11 is located at the bottom dead center). The stroke of the piston rod 11 is the distance from the point where the oil passage 11b has passed above the inflow port 6).

  The head cover 1c is a cylindrical member with a bottom, and the lower end outer periphery of the tube body 1a is screwed into the upper surface opening concave hole 4. An O-ring is fitted between the inner circumference of the upper opening concave hole 4 and the lower circumference of the lower end of the tube body 1a. In this manner, with the outer circumference of the lower end of the tube body 1a screwed to the head cover 1c and the rod cover 1b screwed to the inner circumference of the upper end of the tube body 1a, the upper surface of the cylinder tube 1 from the rod cover 1b to the head cover 1c. The bottomed recessed hole is a piston housing hole 1h, and the pressure oil chamber 10 is between the hole bottom 1s of the piston housing hole 1h and the rod insertion end 11a of the piston rod 11.

The head cover 1c of the cylinder tube 1 is provided with a pressure oil discharge passage H2 from the pressure oil chamber 10 to the discharge port 7. The logic valve 20 is provided in the middle of the pressure oil discharge passage H2.
The pressure oil discharge passage H2 is an L-shaped path that opens at the center of the pressure oil chamber 10 and is connected to the discharge port 7 provided on the side surface of the head cover 1c. The body housing hole 25 is formed, and the small-diameter portion of the valve body housing hole 25 that is open to the pressure oil chamber 10 is the valve seat opening 26. The valve seat opening 26 has a smaller diameter than the valve body housing hole 25, and the corners of the circle serve as the valve seat 24 of the logic valve 20.
The opening / closing valve body 21 that constitutes the logic valve 20 is housed in the valve body housing hole 25 and is movable in the axial direction. The discharge port 7 for the pressure oil Y is opened on the inner side surface of the valve body housing hole 25 in which the opening / closing valve body 21 slides.
A lid member 28 provided with a pilot port 29 is attached to the opening of the valve body housing hole 25 toward the outer surface side.

A surface of the opening / closing valve body 21 that contacts the valve seat 24 is formed in a truncated cone shape, and the valve seat contact surface 22 contacts the entire circumference of the circular valve seat 24 to close the valve seat 24, When the valve seat contact surface 22 is separated from the valve seat 24, the valve body housing hole 25 and the discharge port 7 for the pressure oil Y communicate with each other, and the pressure oil Y in the pressure oil chamber 10 is discharged.
In this embodiment, a compressed valve spring 23 is housed in the lower opening hole provided inside the opening / closing valve body 21, and the lower end of the valve spring 23 elastically contacts the lid member 28 for opening / closing. The valve seat abutment surface 22 of the valve body 21 is pressed against the entire circumference of the valve seat 24 by a predetermined elastic force, and the pressure oil discharge passage H2 is always closed. Then, when the pilot port 29 is connected to the lower opening hole provided inside the opening / closing valve body 21 and the pressure P1 of the pressure oil Y is applied to the pilot port 29, the opening / closing valve body 21 opens the valve with the pressure P1. The elastic force of the spring 23 presses the valve seat 24.
Since the valve spring 23 is pressed against the pilot port 29 by the pressure P1 of the pressure oil Y in the closing direction of the valve seat 24 as described above, it is not always necessary, but when the valve spring 23 is installed as shown in FIG. A material having a weak elasticity enough to lift the valve body 21 is selected. Here, a case where the valve spring 23 is attached will be described as a typical example.

The piston rod 11 is a cylindrical member and is slidably inserted in the insertion / removal direction along the central axis of the cylinder tube 1. The piston rod 11 is provided with a through hole that vertically penetrates in conformity with the central axis of the piston rod 11. The head side closing screw 16 is provided at the lower end of the hole, and the upper end of the through hole is cylindrical and has a male outer peripheral surface. A mounting screw 18 in which a screw is engraved is screwed, and a space between the mounting screw 18 and the head-side closing screw 16 serves as a storage space 12. A concave portion 15 forming a part of the pressure oil chamber 10 is provided on the end surface of the lower end of the piston rod 11 (on the side of the head cover 1c). Therefore, the head-side closing screw 16 is screwed to the inner peripheral surface of the portion of the through hole that opens in the recess 15.
In this embodiment, the inner space of the storage space 12 is formed in two steps with a large diameter on the upper side and a small diameter on the lower side. These are referred to as a large diameter hole portion 12a and a small diameter hole portion 12b, respectively.

  A plurality of communication holes 14 are provided outside the small-diameter hole portion 12b for communicating the large-diameter hole portion 12a with the recess 15 provided at the insertion end of the piston rod 11. A communication portion between the communication hole 14 and the large diameter hole portion 12a is referred to as a communication opening 17.

The storage space 12 accommodates a spool 30, which constitutes a part of a pressure (and further temperature) compensation type flow rate control mechanism, an opening adjustment pin member 40, and an elastic member 50 formed of a coil spring.
The spool 30 of this embodiment is composed of a spool body 31 and a pressure reducing block 32 (FIG. 3). Of course, the spool body 31 and the decompression block 32 can be made integrally. The spool body 31 has a shape that matches the shape of the inner surface of the storage space 12, and is composed of a body portion 31 a and a top portion 39. The body portion 31a is thinner than the top portion 39 and is inserted into the small diameter hole portion 12b. The outer diameter of the body portion 31a is formed to have the same diameter as the small diameter hole portion 12b, and is slidably inserted. At the boundary between the top portion 39 and the body portion 31a, the lower surface of the top portion 39 is a jaw portion 39a, and the jaw portion 39a engages with and disengages from the contact surface 11k.

  A through cavity extending from the body portion 31a to the top portion 39 is formed on the inner surface of the spool body 31, and the body portion 31a has a body hollow portion 36 which is a lower portion of the through cavity, and the top portion 39 has an upper portion of the through cavity. The valve element housing hollow portions 37 are formed so as to communicate with each other. The inner diameter of the valve body housing hollow portion 37 is formed larger than the inner diameter of the body side hollow portion 36. A step is formed at the boundary between the body side hollow portion 36 and the valve body housing hollow portion 37.

  The body portion 31a is provided with a spool side oil passage hole 38 which communicates with the rod side oil passage hole 11b of the piston rod 11. The spool-side oil passage hole 38 is formed at a position communicating with the rod-side oil passage hole 11b in a state where the jaw 39a is engaged with the contact surface 11k (that is, a state before the operation of the hydraulic cylinder 100). And is opened in the small-diameter hole portion 12b (FIG. 3 (b)). As will be described later, the opening width in the direction of the rod-side oil passage hole 11b, which is in contact with the spool-side oil passage hole 38 of the spool 30 that slides in the vertical direction, is such that when the spool 30 slides up and down a short distance. The spool-side oil passage hole 38 is provided in such a size that it does not come off from the rod-side oil passage hole 11b. In other words, the spool 30 slides up and down a short distance within a range in which the spool-side oil passage hole 38 does not deviate from the opening width of the rod-side oil passage hole 11b.

  The relationship between the outer peripheral surface of the top portion 39 and the inner peripheral surface of the large diameter hole portion 12a is such that the top portion 39 is formed thinner than the large diameter hole portion 12a, and between the top portion 39 and the large diameter hole portion 12a. A second gap 17a reaching the communication opening 17 is formed.

As shown in FIG. 4, the decompression block 32 is housed in the valve body housing hollow portion 37 of the top portion 39, and is fixed so as not to fall off by the elastic member 50 via the washer. The decompression block 32 is provided with a recessed hole portion 33 having an upper surface opening except for the partition wall 34, and a decompression hole 35 is formed in the partition wall 34 provided at the bottom of the recessed hole portion 33. The decompression hole 35 is open to the body-side hollow portion 36.
As the decompression hole 35, a choke hole, a thin blade orifice hole, or the like is used. Here, the pressure reducing hole 35 is a thin blade orifice hole.

When the pressure reducing hole 35 is a thin blade orifice hole as described above, the thickness T1 around the hole edge 35a of the pressure reducing hole 35 (thin blade orifice hole) is preferably as small as possible, and the thickness T1 is at most the diameter of the pressure reducing hole 35. It is required to be ⅕ or less of D1 (FIG. 4). If the cross section of the partition wall 34 is formed in a triangular knife edge shape around the pressure reducing hole 35 on both sides thereof, the thickness T1 around the hole edge 35a is close to 0, which satisfies the above 1/5 or less. Further, it is preferable that the angle α of the hole edge 35a is smaller within a range in which the partition wall 34 can withstand the pressure of the pressure oil Y passing through the pressure reducing hole 35.
The actual pressure reducing hole 35 is a small hole of 1 mm or less (0.6 mm in this embodiment).

  As described above, the cylindrical mounting screw 18 is screwed into the upper opening of the large-diameter hole 12a of the piston rod 11 via the O-ring, and the insertion end of this mounting screw 18 and the spool 30 are screwed together. An elastic member 50 such as a coil spring is inserted between the top portion 39 and the top portion 39, and constantly presses the spool 30 in the head direction (downward) with a constant elastic force through a washer. In the initial inoperative state, the pushed jaw portion 39a of the spool 30 engages with the abutting surface 11k of the small diameter hole portion 12b and is pushed.

A tubular hollow sleeve 19 is disposed inside the elastic member 50. A male screw portion is engraved on the outer circumference of the upper end of the hollow sleeve 19, and a female screw portion is engraved on the inner circumference of the upper end.
A male screw portion formed on the outer periphery of the upper end of the hollow sleeve 19 is screwed and fixed to a female screw portion formed on the inner peripheral surface of the upper end of the hollow cylindrical mounting screw 18. Further, a hexagonal wrench hole serving as an operating portion 19a is formed on the inner surface of the upper opening of the hollow sleeve 19. Normally, the hollow sleeve 19 is set in the mounting screw 18 in a fixed state, but by using the wrench hole (operating portion) 19a, the hollow sleeve 19 can be screwed forward and backward with respect to the mounting screw 18. The hollow sleeve 19 is disposed so as to extend toward the decompression block 32, and the tip end 19b thereof is aligned with the concave hole portion 33 of the decompression block 32 and is disposed in close proximity thereto as shown in FIG. The tip 19b is formed in a conical shape. This hollow sleeve 19 is a hollow body having a cavity that penetrates vertically, and a hole is formed at the center of its tip 19b. When the hollow sleeve 19 is moved in the direction of the decompression block 32 by turning the wrench hole 19a, the outer periphery of the tip end 19b comes into contact with the opening edge of the concave hole portion 33 and closes the concave hole portion 33. As a result, the pressure oil Y does not flow into the decompression block 32.

An opening adjustment pin member 40 is coaxially mounted in the hollow sleeve 19 so as to be able to advance and retract. The opening adjustment pin member 40 is a thin rod-shaped member having a male screw portion formed on the upper end portion, a driver groove serving as the operating portion 41 at the piston-side end portion of the upper end, and a sharp pin 42 at the lower end portion. The male screw portion of the upper end portion is screwed into the female screw portion of the upper end portion of the hollow sleeve 19, and the driver groove (operation portion) 41 is used to advance / retreat.
The pin 42 having a sharp tip is provided so as to project from the through hole at the lower end of the hollow sleeve 19 toward the pressure reducing hole 35 at a position corresponding to the pressure reducing hole 35. By operating the driver groove 41 and rotating the opening adjustment pin member 40, the amount of protrusion of the pin 42 from the through hole can be adjusted, and by inserting and removing the sharp tip of the pressure reducing hole 35, the pressure reducing hole 35 The opening is adjusted. The opening adjustment pin member 40 is also provided with an O-ring to prevent oil leakage (FIG. 1).

In the above configuration, the pressure oil inflow path H1 includes the inflow port 6, the first gap 3 between the cylinder tube 1 and the piston rod 11, the rod side oil passage hole 11b provided in the piston rod 11, and the spool side oil passage. It is composed of the hole 38 and the body-side hollow portion 36 of the spool 30, and when the hydraulic cylinder 100 operates, the pressure oil Y flows into the body-side hollow portion 36 through this route.
On the other hand, the pressure oil passage H3 includes a pressure reducing hole (orifice hole) 35 in the partition wall 34 of the pressure reducing block 32, a concave hole portion 33 of the pressure reducing block 32, and a large-diameter hole portion continuous with the upper opening of the concave hole portion 33. 12a, a second gap 17a between the top portion 39 and the inner peripheral surface of the large diameter hole portion 12a, a communication opening 17, and a communication hole 14 reaching the pressure oil chamber 10, and the pressure oil passing through the pressure reducing hole 35. Y flows into the pressure oil chamber 10 through this route. It should be noted that the boundary of the members in the hydraulic cylinder 100 is provided with an O-ring or an oil seal for preventing oil leakage as described above.

  Next, a hydraulic circuit used by mounting a large number of hydraulic cylinders 100 with a tuning function of the present invention on a mechanical equipment M such as a die press will be described (FIGS. 1 and 8 to 10). The mechanical equipment M is provided with a pedestal 110 on which a lower die 120 is installed, and cylinder mounting holes 111 are formed at predetermined intervals. The hydraulic cylinder 100 is inserted into the cylinder mounting hole 111, and its flange 1d is bolted to the base 110. The lower die 120 is provided with a knockout hole 121 in which the piston rod 11 appears and disappears in accordance with the cylinder mounting hole 111 (FIG. 1).

A large number of hydraulic cylinders 100 mounted on the base 110 are connected to the hydraulic circuits shown in FIGS. The hydraulic circuit will be described with reference to the first embodiment shown in FIG. 8, and then the modified examples shown in FIGS. 9 and 10. 9 and 10, in order to avoid complication, the description will focus on parts different from FIG.
The larger the number of hydraulic cylinders 100 mounted on the base 110, the more effective.

The hydraulic circuit includes a hydraulic pump 130, a tank 140, a direction switching valve 150, and pipes 200, 210, 220, 230 and 240 connecting these. The direction switching valve 150 has a P port connected to the hydraulic pump 130, an A port which is an outlet of the P port, a B port connected to the tank 140, and an E port which is an inlet thereof.
The main pipe 200 is a pipe shown by a thick solid line from the hydraulic pump 130 to the inflow port 6, the pilot pipe 210 is a pipe shown by a thin solid line from the pilot port 29 to the branch point S of the main pipe 200, and the discharge pipe 220 is from the discharge port 7. The pipe to the tank 140 is indicated by a broken line, the loop pipe 230 is indicated by a one-dot chain line connecting the B port and the E port, and the connection pipe 240 is indicated by a thin solid line connecting the loop pipe 230 and the discharge pipe 220.
The hydraulic pump 130 is connected to the inflow port 6 of each hydraulic cylinder 100 via the main pipe 200. The pilot pipe 210 branched from the branch point S of the main pipe 200 is connected to the pilot port 29 of each logic valve 20 of each hydraulic cylinder 100 through the P port of the direction switching valve 150 to the A port, and the logic valve 20 is closed. Pressurizing in the direction.

  The discharge port 7 of the logic valve 20 installed in the cylinder tube 1 is connected to the tank 140 via a discharge pipe 220. The E port and the B port of the direction switching valve 150 are connected by a loop pipe 230, and the loop pipe 230 is connected by a connection pipe 240 to the discharge pipe 220 and is connected to the tank 140.

Next, the tuning operation of the mechanical equipment M will be described. A lower die 120 is set on the base 110.
Before the operation of the hydraulic cylinder 100 (FIG. 1), the P port of the direction switching valve 150 of the hydraulic circuit is connected to the B port, the pressure oil Y from the hydraulic pump 130 flows from the loop pipe 230 to the connection pipe 240, and the tank 140 Have returned to. At this time, the A port of the direction switching valve 150 is connected to the E port, and the pilot port 29 of the logic valve 20 is connected to the tank 140 via the pilot pipe 210. Therefore, no pressure is applied to the inflow port 6 of all the hydraulic cylinders 100 and the pilot port 29 of the logic valve 20, and the logic valve 20 is opened / closed by only the elastic force of the valve spring 23. It is closed by 21.
Then, as described above, the pressure oil Y from the hydraulic pump 130 is returned to the tank 140 as it is, so that the pressure does not rise in the inflow port 6. Therefore, the pressure of the pressure oil Y does not act on all the hydraulic cylinders 100 installed on the base 110, and the piston rod 11 is recessed in the cylinder tube 1 and coincides with the upper surface of the base 110. (Fig. 1).
At this point, the spool 30 is pushed down by the elastic force of the elastic member 50 as shown in FIG. 1, the jaw 39a thereof is pressed against the contact surface 11k, and the spool-side oil passage hole 38 of the spool 30 is shown in FIG. As shown in (b), the rod-side oil passage holes 11b are aligned and communicate with each other.

In this state, the sheet metal 300 to be formed is placed on the lower die 120, and the upper die (not shown) is operated to press-form the sheet metal 300. Then, when the molding of the sheet metal 300 is completed and the upper die is lifted, the direction switching valve 150 is operated to remove the molded product (sheet metal) 300 formed in conformity with the lower die 120 from the lower die 120. It will be. At this time, depending on the shape of the lower mold 120, the lifting force (load) required for die cutting may differ due to galling or the like to the lower mold 120 of the molded product 300 in each part of the lower mold 120.
This load is represented by F, and in FIGS. 8 and 9, the load F in the installation portion of each hydraulic cylinder 100 is given a branch number and is represented as F1, F2 ... Fn.

When the upper die is lifted and the press working is completed, the direction switching valve 150 is operated as described above to switch the connection of the ports so that the P port and the A port and the B port and the E port are connected. As a result, the pressure oil Y from the hydraulic pump 130 returning to the tank 140 via the loop pipe 230 goes through the main pipe 200 toward the inflow ports 6 of all the hydraulic cylinders 100, and the pressure is applied to the inflow ports 6. give. This pressure is P1 (FIGS. 1 and 2).
The pressure P1 standing on the inflow port 6 is transmitted to the body-side hollow portion 36 in the spool 30 through the pressure oil inflow passage H1. Since there is a pipe resistance in the pressure oil inflow passage H1, the pressure in the body-side hollow portion 36 is slightly reduced. The pressure inside the body-side hollow portion 36 is P2. The pressure P2 in the body-side hollow portion 36 is transmitted from the pressure reducing hole 35 to the pressure oil chamber 10 through the pressure oil passage H3.
The pressure oil Y in the pressure oil chamber 10 continues to increase while the inflow continues and pushes up the piston rod 11. The operation of the spool 30 during this time will be described later.

  The pressure P3 in the portion from the pressure oil passage H3 to the pressure oil chamber 10 is transmitted through the fine pressure reducing holes 35, and therefore is smaller than the pressure P2 in the body-side hollow portion 36. Although the logic valve 20 is attached to the pressure oil discharge passage H2 of the pressure oil chamber 10, the pilot port 210 of this logic valve 20 is connected to the pilot pipe 210 branched from the main pipe 200, The pressure P1 in the main pipe 200 is applied to the pilot port 29. Therefore, the opening / closing valve body 21 of the logic valve 20 is closed by the sum of the pressure P1 and the elastic force of the valve spring 23 of itself. The sum of the pressure P1 and the elastic force is larger than the pressure P3 of the pressure oil chamber 10, and the pressure oil discharge passage H2 does not open during the operation of the hydraulic cylinder 100.

  Here, the operation of the spool 30 will be described. When the pressure P1 rises in the inflow port 6 due to the port switching of the direction switching valve 150 as described above, the pressure inside the body-side hollow portion 36 instantly becomes P2, and the pressure in the pressure oil chamber 10 becomes P3. At the initial stage (the stage where the piston rod 11 rising from the bottom dead center is not in contact with the molded product 300), the pressure P2 is considerably higher than the pressure P3 in the pressure oil chamber 10. The pressure oil Y having the pressure P1 passes through the pressure oil inflow passage H1 as described above and flows into the body-side hollow portion 36 of the spool 30 through the sprue-side oil passage hole 38 (FIG. 3B).

  The pressure oil Y that has flowed into the body-side hollow portion 36 first enters between the insertion end 31b of the spool 30 and the head-side closing screw 16 that forms the hole bottom of the storage space 12, and the elastic member The spool 30 is rapidly lifted in the direction of compressing 50 (FIG. 3 (c)). The bending of the elastic member 50 is added to the pressure P3 on the pressure oil chamber 10 side, and as will be described later, the spool 30 stops when the pressure P2 and the pressure P3 are balanced. Then, while keeping this state, the piston rod 11 continues to rise as will be described later.

  The positional relationship between the spool-side oil passage hole 38 and the rod-side oil passage hole 11b is such that when the spool 30 moves in the lifting direction as described above, as shown in FIGS. The oil hole 38 gradually deviates from the rod side oil passage hole 11b, and the supply of the pressure oil Y from the rod side oil passage hole 11b to the spool side oil passage hole 38 is restricted. During this time, the pressure oil Y continues to flow into the pressure oil chamber 10 by being supplied with the pressure oil Y to the inflow port 6 while being throttled. Due to the continuous inflow of the pressure oil Y into the pressure oil chamber 10, the piston rod 11 continues to rise.

この式から、この状態の差圧（Ｐ２−Ｐ３）を出すと、
差圧（Ｐ２−Ｐ３）＝Ｋ（Ｘ＋△ｘ）／Ａとなる。
Ｋ、Ｘ、△ｘ、及びＡは一定の値であるから、差圧（Ｐ２−Ｐ３）も一定の値となる。 Here, the pressure receiving area of the spool 30 is A, the spring constant of the elastic member 50 is K, the initial amount of deflection when the elastic member 50 is set is X, inside and outside the decompression hole 35 (partition wall 34) before the balance. Assuming that the flexure amount (compression amount) of the elastic member 50 corresponding to the differential pressure ΔP (P2-P3) is Δx, the force relationship between the inside and outside of the pressure reducing hole 35 is expressed by the following equation.

From this equation, if the differential pressure (P2-P3) in this state is calculated,
The differential pressure (P2-P3) = K (X + Δx) / A.
Since K, X, Δx, and A are constant values, the differential pressure (P2-P3) is also a constant value.

  In this state (while maintaining a constant differential pressure), the pressure oil Y continuously flows from the pressure reducing hole 35 into the pressure oil chamber 10 through the pressure oil passage H3, and the piston rod 11 rises as described above. Then, the molded product 300 is contacted.

When the piston rod 11 contacts the molded product 300 and then pushes it up, the load F of the molded product 300 is applied to the piston rod 11. (That is, the loads F1 to Fn are applied to the n piston rods 11.) In other words, the load F is added to the pressure P3 side, and the balance with the pressure P2 side is lost. That is, the force relationship between them is AP3 + K (X + Δx) + F> AP2.
As a result, the pressure P2 side loses the pressure P3 side, and the elastic member 50 instantly extends by an amount corresponding to the increased load F on the pressure P3 side to push down the spool 30. The amount of extension is Δx1. As a result, the communication area between the spool-side oil passage hole 38 and the rod-side oil passage hole 11b increases, and the pressure on the pressure P2 side increases. The increase amount of the pressure on the pressure P2 side is ΔAP2. On the other hand, the expansion of the elastic member 50 reduces the force on the pressure P3 side. As a result, the pressure inside and outside the pressure reducing hole 35 reaches a new balanced state.
That is, the state of “AP3 + K (X + Δx−Δx1) + F = AP2 + ΔAP2” is established, and lifting of the molded product 300 is started.
Here, the differential pressure (P2-P3)
= K (X + Δx) / AK · Δx1 / A-ΔP2 + F / A.
F / A is the increased pressure per unit area due to the load F, -K · Δx1 / A is the decreased pressure per unit area due to the expansion of the elastic member 50 due to the load F, and ΔP2 is the increase due to the load F on the pressure P2 side. Because it's pressure
The increased pressure per unit area due to the load F becomes equal to the sum of the decreased pressure per unit area due to the expansion of the elastic member 50 due to the load F and the increased pressure on the pressure P2 side due to the load F.
That is, K · Δx1 / A + ΔP2 = F / A, which is zero.
As a result, also in this case, the differential pressure (P2−P3) = K (X + Δx) / A, which always has a constant value.

  As described above, the load F (including F = 0) applied to each hydraulic cylinder 100 is different, and the load F may fluctuate during the protrusion process of the piston rod 11. However, despite the fluctuation of the load F (including the load 0), each hydraulic cylinder 100 operates under a constant differential pressure (P2-P3), and the multiple hydraulic cylinders 100 all have the same speed and the same timing. Then, the ejecting operation is performed (pressure compensation).

  As described above, the amount of movement of the spool 30 in each hydraulic cylinder 100 (that is, the change in the amount of flexure Δx of the elastic member 50) corresponding to the load F varies depending on the load F applied to each hydraulic cylinder 100. Since it is performed instantaneously in response to load fluctuations, even if the load F applied to each hydraulic cylinder 100 is different, or even if there is a load fluctuation in the middle, the entire hydraulic cylinders 100 operate simultaneously and the piston rod 11 Rises at the same speed, pushes up the molded product 300 without excess or deficiency, and completes the die cutting when reaching the top dead center.

When the die cutting is completed, the port is switched again. As a result, the pilot pipe 210 is connected to the tank 140, and the pressure P1 applied to the opening / closing valve body 21 of the logic valve 20 becomes zero, and is pressed against the valve seat 24 only by the elastic force of the valve spring 23.
On the other hand, the pressure P3 in the pressure oil chamber 10 is sufficiently high, and the self-weight of the piston rod 11 is applied to it, which is larger than the elastic force of the valve spring 23 of the opening / closing valve body 21, so that the valve spring 23 is pressed and bent. The pressure oil discharge passage H2 is opened, and the pressure oil Y in the pressure oil chamber 10 returns to the tank 140. As a result, the piston rod 11 is returned and is immersed in the cylinder tube 1 as shown in FIG.
The inflow port 6 side is also connected to the tank 140, and the pressure to the inflow port 6 becomes zero. Then, as in the beginning, the pressure oil Y from the hydraulic pump 130 returns to the tank 140 through the loop pipe 230 and the connection pipe 240.

Even if all the hydraulic cylinders 100 used for the die-cutting work as described above are made to have the same specifications, it is inevitable that a machine difference based on the machining tolerance will occur. In addition, the operation of all the hydraulic cylinders 100 may not be completely synchronized at the installation stage due to the relationship with the lower die 120 or other causes. In that case, it is necessary to individually finely adjust the opening area of the minute pressure reducing holes 35.
In the adjustment, a driver is inserted from the opening of the hollow sleeve 19 at the center position of the piston rod 11 appearing on the surface of the base 110 to use the driver groove (operation portion) 41 of the opening adjustment pin member 40, The opening adjustment pin member 40 is moved back and forth to adjust the opening area of the decompression hole 35.

  When the opening area of the pressure reducing hole 35 is adjusted, the flow of the pressure oil Y passing through the pressure reducing hole 35 changes. That is, when the opening area of the decompression hole 35 is reduced to make the pressure oil Y difficult to flow, the time until the differential pressure ΔP (P2-P3) becomes constant becomes long, and the responsiveness of the piston rod 11 to the load fluctuation is slow. Become. By adjusting the hydraulic cylinders 100 individually, the responsiveness of the entire hydraulic cylinders 100 can be made uniform.

Further, depending on the shape of the molded product 300, it may not be necessary to use all of the hydraulic cylinders 100 mounted on the bed 110. In this case, as shown by the broken line in FIG. 4, the hollow sleeve 19 of the unused hydraulic cylinder 100 is operated to close the upper opening of the recessed hole portion 33 of the decompression block 32 with the truncated cone-shaped tip 19b thereof. Become. When the upper surface opening of the recessed hole portion 33 is closed by the tip 19b, the pressure oil Y cannot pass through the pressure reducing hole 35 and flow into the pressure oil chamber 10 while the other hydraulic cylinder 100 is operating, and the stopped state is maintained. . As a result, only the necessary portion of the hydraulic cylinder 100 can be operated.
The upper end of the hollow sleeve 19 is exposed on the upper end surface of the cylinder tube 1 as shown in FIG. 1, and the hollow sleeve 19 is rotated by inserting a wrench into the hexagonal wrench hole (operating portion) 19a. The sleeve 19 can be screwed and unscrewed.

Ｑ：流量
Ｃ：常数
ａ：減圧孔の面積
ｇ：重力加速度
γ：圧油の比重量
減圧孔３５を通過した圧油Ｙはピストンロッド１１のロッド挿入端１１ａに作用し、ピストンロッド１１を押し上げ、ロッドアウトする。その押上力は（Ｂ−Ａ）Ｐ３となる。 Next, the temperature compensation of the present invention will be described. The hydraulic device operates the hydraulic pump 130 to suck and discharge the pressure oil Y, thereby supplying the high-pressure pressure oil Y to the hydraulic cylinder 100. The flow of the pressure oil Y changes in a complicated and abrupt manner in the hydraulic circuit, which causes a temperature rise in the pressure oil Y and changes the performance. Therefore, the operating temperature range of the pressure oil Y is determined. However, when the oil temperature rises even within the predetermined operating temperature range, the viscosity of the pressure oil Y gradually decreases, which affects the pressure P generated in the hydraulic equipment.
When the pressure reducing hole 35 of the present invention is the thin blade orifice hole, the pressure oil Y always passes through the pressure reducing hole 35 while maintaining the differential pressure ΔP. The flow rate in that case is shown by the following formula.

Q: Flow rate C: Constant number a: Area of pressure reducing hole g: Gravitational acceleration γ: Specific weight of pressure oil The pressure oil Y that has passed through the pressure reducing hole 35 acts on the rod insertion end 11a of the piston rod 11 and pushes up the piston rod 11. , Rod out. The pushing force is (B−A) P3.

  Since the mathematical expression 2 is not affected by the temperature, the flow rate Q passing through the pressure reducing hole 35 does not change with respect to the temperature change of the pressure oil Y as described above. In other words, the operation of the hydraulic cylinder 100 is not affected by the temperature change of the pressure oil Y. As a result, the hydraulic cylinder 100 of the present invention also has a temperature compensation function.

Next, the hydraulic circuit shown in FIG. 9 will be described. It is basically the same as FIG. 8, except that the branch point S between the main pipe 200 and the pilot pipe 210 is upstream of the direction switching valve 150 in FIG. 8 and is downstream in FIG. is there.
In FIG. 10, a B port pipe 231 for discharging the pressure oil Y from the B port to the tank 140 is provided instead of the loop pipe 230, and the connection pipe 240 is connected to the E port. In the case of FIGS. 8 and 9, a large amount of pressure oil Y from the hydraulic pump 130 may flow to the connection pipe 240 when not operating, which may cause a trouble. However, by providing the B port pipe 231, By separating the discharge pipe 220 and the B port pipe 231, the above trouble can be eliminated.

  Since the hydraulic cylinder 100 according to the present invention has a tuning function, even if a large number of hydraulic cylinders are used in hydraulic equipment, a tuning operation can be realized without a complicated hydraulic circuit.

1: Cylinder tube, 1a: Tube body, 1b: Rod cover, 1c: Head cover, 1d: Flange, 1h: Piston storage hole, 1s: Hole bottom, 2: Sliding hole, 3: First gap, 4: Top opening Recessed hole, 6: inflow port, 7: discharge port, 10: pressure oil chamber, 11: piston rod, 11a: rod insertion end, 11b: rod side oil passage hole, 11k: contact surface, 12: storage space, 12a : Large diameter hole portion, 12b: Small diameter hole portion, 14: Communication hole, 15: Recessed portion, 16: Head side closing screw, 17: Communication opening, 17a: Second gap, 18: Mounting screw, 19: Hollow sleeve, 19a: Wrench hole (operation part), 19b: Tip, 20: Logic valve, 21: Open / close valve body, 22: Valve seat contact surface, 23: Valve spring, 24: Valve seat, 25: Valve body storage hole, 26: valve seat opening, 28: lid member, 29: pilot 30: spool, 31: spool body, 31a: body portion, 31b: insertion end, 32: decompression block, 33: recessed hole portion, 34: partition wall, 35: decompression hole (orifice hole), 35a: hole edge , 36: Body side hollow part, 37: Valve body housing hollow part, 38: Spool side oil passage hole, 39: Top part, 39a: Jaw part, 40: Opening adjustment pin member, 41: Driver groove (operating part) , 42: pin, 50: elastic member, 100: hydraulic cylinder (with tuning function), 110: base, 111: cylinder mounting hole, 120: lower mold, 121: knockout hole, 130: hydraulic pump, 140: Tank, 150: Direction switching valve, 200: Main pipe, 210: Pilot pipe, 220: Discharge pipe, 230: Loop pipe, 231: B port pipe, 240: Connection pipe ,: 300: Molded product (sheet metal), D : Diameter of pressure reducing hole, F / F1 / F2 / Fn: Load, H1: Pressure oil inflow path, H2: Pressure oil discharge path, H3: Pressure oil flow path, M: Mechanical equipment, S: Branch point, T1: Thickness around hole edge, Y: Pressure oil, α: Angle of hole edge

Claims (9)

A cylinder tube having a pressure oil inflow port and a pressure oil discharge port;
A piston rod that is housed so that it can be retracted from the rod-side end surface of the cylinder tube, and a storage space that extends in the axial direction is formed inside;
A pressure oil chamber that is formed in the cylinder tube and is provided between a hole bottom of a piston housing hole that houses the piston rod and a rod insertion end of the piston rod, and that pushes out the piston rod by the inflow of pressure oil,
A pressure oil discharge path connected to the discharge port from the pressure oil chamber,
A tubular spool disposed in the storage space on the head side and slidably inserted into the storage space;
An elastic member that is disposed on the rod side in the storage space and presses the spool toward the hole bottom side of the piston storage hole,
A partition provided in the spool and having a pressure reducing hole,
A pressure oil inflow path extending from the inflow port to the front of the partition wall;
A hydraulic cylinder with a tuning function, comprising: a hydraulic fluid passage extending from the back of the partition wall to a hydraulic fluid chamber.   An opening degree adjusting pin member that is arranged in conformity with the pressure reducing hole of the partition wall and that is close to or away from the pressure reducing hole and adjusts the opening degree of the pressure reducing hole is provided in the piston rod. 1. A hydraulic cylinder with a tuning function according to 1.   The hydraulic cylinder with a tuning function according to claim 1 or 2, wherein a hollow sleeve that opens and closes a pressure oil passage provided on the downstream side of the partition wall is provided inside the piston rod.   The opening degree adjusting pin member and the hollow sleeve are arranged coaxially, and the operation portion of the opening degree adjusting pin member and the hollow sleeve is exposed to the rod-side end surface of the piston rod. Hydraulic cylinder with tuning function.   The hydraulic cylinder with a tuning function according to any one of claims 1 to 4, wherein the pressure reducing hole is a thin blade orifice hole. A logic valve installed in the pressure oil discharge passage is added,
The logic valve is connected to a valve body for opening and closing the pressure oil discharge passage H2 and a pipe connected to the inflow port during the piston rod protrusion work, and is used for circulating the pressure oil at the end of the piston rod protrusion work. 6. A hydraulic cylinder with a tuning function according to any one of claims 1 to 5, further comprising a pilot port connected to the tank. The hydraulic cylinders with a plurality of tuning functions according to claim 6, wherein the plurality of hydraulic cylinders are installed on the base so that the piston rod is projected and retracted from the base of the mechanical equipment.
A hydraulic pump for sending pressure oil to the hydraulic cylinder with the tuning function,
A tank for collecting pressure oil from the hydraulic cylinder with the synchronizing function;
It has ports P, A, E, and B for switching the supply direction of the pressure oil from the hydraulic pump and the return direction of the pressure oil to the tank, and the P-A port when the piston rod is projected. A direction switching valve that connects the E-B port and connects the P-B port and the E-A port when the piston rod is retracted,
A main pipe connecting the hydraulic pump and the inflow port of the hydraulic cylinder with the synchronizing function,
Pilot piping that branches from the main piping and is connected to the P port, and that is connected from the A port to the pilot port of the logic valve;
A discharge pipe that connects the discharge port of the hydraulic cylinder with a tuning function and the tank,
Loop piping connecting the B port and the E port,
A hydraulic system comprising: the loop pipe and a connection pipe connected to the discharge pipe. The hydraulic cylinders with a plurality of tuning functions according to claim 6, wherein the plurality of hydraulic cylinders are installed on the base so that the piston rod is projected and retracted from the base of the mechanical equipment.
A hydraulic pump for sending pressure oil to the hydraulic cylinder with the tuning function,
A tank for collecting pressure oil from the hydraulic cylinder with the synchronizing function;
It has ports P, A, E, and B for switching the supply direction of the pressure oil from the hydraulic pump and the return direction of the pressure oil to the tank, and the P-A port when the piston rod is projected. A direction switching valve that connects the E-B port and connects the P-B port and the E-A port when the piston rod is retracted,
A main pipe connecting the hydraulic pump and the P port, and connecting the A port and the inflow port of the hydraulic cylinder with a tuning function;
A pilot pipe branching from the main pipe downstream of the A port and connected to the pilot port of the logic valve;
Discharge pipe connecting the discharge port 7 tank of the hydraulic cylinder with synchronization function,
Loop piping connecting the B port and the E port,
A hydraulic system comprising: the loop pipe and a connection pipe connected to the discharge pipe.   The hydraulic system according to claim 7 or 8, wherein, instead of the loop pipe, a B port pipe for discharging pressure oil from the B port to the tank is provided and the connection pipe is connected to the E port. apparatus.

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