JP2015167996A - hydraulic press - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic press of which whole can be made compact.SOLUTION: A hydraulic press having a main body, a slide, and a press cylinder for driving the slide includes a pressure oil supply and discharge cylinder 20 which supplies a hydraulic oil to the press cylinder and is driven by a servo motor. Four pressure oil supply and discharge cylinders 20 are provided for the press cylinder, and each of said four pressure oil supply and discharge cylinders is attached to a side face of the press main body in a standing state. Consequently, the whole device is made so compact as to enable installation of the press in a small space. Each pressure oil supply and discharge cylinder 20 has a cylinder as a basic structure, whereby a stroke can be easily elongated and a long pressure stroke can be achieved. Further, control for a discharge quantity can be correctly achieved by an integrated rotation amount and rotation numbers (rpm) of the servo motor M.

Description

  The present invention relates to a hydraulic press. More specifically, the present invention relates to a hydraulic press including a hydraulic device as a drive source.

  The hydraulic press requires a large hydraulic device as a drive source, and a hydraulic chamber is installed separately from the press body, and the press body and hydraulic chamber are connected by piping to supply and discharge pressure oil. Has been. In such a hydraulic press, since supply and discharge of pressure oil are repeatedly performed with high frequency, impacts are easily generated in the piping, and a complicated system design is required to avoid this. In addition, it is necessary to provide measures to prevent oil leakage in order to control a large amount of hydraulic oil. Hydraulic presses have these unique problems.

  In order to cope with the above problems in the hydraulic press, there is a conventional technique in which a cylinder that supplies hydraulic oil by driving a servo motor is connected to an oil chamber provided on the slide, and the operation of the slide is controlled by controlling the servo motor driving. Known (see Patent Document 1 and Patent Document 2).

However, the prior art of Patent Document 1 has the following problems.
1) Since only one pressurizing cylinder is used, it is not possible to easily cope with an increase in the amount of hydraulic oil. If it is going to correspond, since it is necessary to lengthen a pressure cylinder, a press apparatus will enlarge.
2) If there is one cylinder for pressurization, there is a problem that an actuator (for example, a servo motor) that drives the cylinder increases in capacity, which increases installation space and increases costs.

  The prior art of Patent Document 2 is provided with two cylinders (master cylinders), one of which is used for high-speed feeding and the other of which is used for pressurization. Even if the number of cylinders is increased in such a manner, the same problem as in 1) and 2) above arises when trying to cope with a longer pressurization stroke during pressurization.

  Furthermore, as a common problem of the prior art, when the press capacity is increased, it is necessary to increase the cross-sectional area of the pressurizing cylinder, so that it is difficult to increase the speed at the time of idle descent and pressurization. Therefore, a hydraulic pump with a large flow rate is required, and sometimes a plurality of pumps are arranged, leading to an increase in size of the hydraulic unit. In addition, high pressure is required in the pressurizing capacity (pressing force), and in order to cope with this, it is necessary to increase the pressure of hoses, piping, packing, valves, and countermeasures against oil leakage, making it difficult to select equipment and increasing costs. There is a problem that leads to.

JP 2006-150422 A JP 2002-295624 A

  In view of the above circumstances, an object of the present invention is to provide a hydraulic press capable of downsizing the entire apparatus while allowing a long press stroke.

A hydraulic press according to a first aspect of the present invention is a hydraulic press having a press body and a press cylinder for molding work attached to the press body, and is driven by a servo motor for supplying hydraulic oil to the press cylinder. A plurality of pressure oil supply / discharge portions are provided, and each pressure oil supply / discharge portion is attached in a standing state on a side surface of the press body. .
The hydraulic press according to a second aspect of the present invention is the hydraulic press according to the first aspect, wherein the press cylinder includes a first cylinder and a second cylinder having an inner diameter larger than that of the first cylinder and formed integrally with the first cylinder. It has a cylinder body and a cylinder rod slidably inserted into the cylinder body.
The hydraulic press according to a third aspect of the present invention is the hydraulic oil supply / discharge cylinder according to the first or second aspect, wherein the pressure oil supply / discharge portion comprises a cylinder portion and a piston that advances and retreats within the cylinder portion by rotation of the servo motor. The pressure oil supply / discharge cylinder is attached to the side surface of the press body so that the longitudinal direction thereof is the vertical direction.
The hydraulic press according to a fourth aspect of the present invention is the hydraulic press according to the second or third aspect, wherein the press body has a crown, the press cylinder is fixed to the crown, and each of the pressure oil supply / discharge portions is a discharge port for hydraulic oil. Is provided at the upper end.
The hydraulic press according to a fifth aspect of the present invention is characterized in that, in the third or fourth aspect, the lengths of the pipes from the discharge ports of the pressure oil supply / discharge sections to the press cylinder are substantially equal.
A hydraulic press according to a sixth aspect of the present invention is characterized in that in any one of the first to fifth aspects, an oil storage section connected to the press cylinder is further provided.
The hydraulic press according to a seventh aspect is characterized in that, in the sixth aspect, the oil storage part is attached to the crown.

According to the first aspect of the present invention, a plurality of pressure oil supply / discharge portions are used and are mounted upright on the side surface of the press body, so that the entire apparatus is compact and the press can be installed in a small space.
According to the second invention, if the cross-sectional area ratio between the first cylinder and the second cylinder is changed, it is possible to switch between high speed driving and high load driving. At high speed and low load far from the bottom dead center, hydraulic pressure is applied to the first cylinder rod having a small cross-sectional area, and the cylinder rod can be driven at high speed. Further, the pressurization at the time of low load and high load near the bottom dead center is such that hydraulic pressure is applied to the second cylinder rod having a large cross-sectional area, and a high load can be generated even at a low speed.
According to the third invention, the pressure oil supply / discharge cylinder has a cylinder as a basic structure, and the discharge amount can be easily increased by increasing the diameter of the oil chamber or by increasing its length. It is easy to lengthen the pressurization stroke of the main cylinder. And the control of the discharge amount can be controlled by the forward / backward movement amount of the piston, which can be achieved by controlling the cumulative rotation amount of the servo motor in the forward / reverse direction, and the control of the forward / backward movement speed can be controlled by the rotational speed. Can be achieved. Therefore, the pressure oil supply amount and the supply speed can be freely controlled.
According to the fourth invention, since the discharge port of the pressure oil supply / discharge cylinder is located at the upper end, the distance from the press cylinder is shortened, and the delay time of the operation supply can be reduced, so that the controllability is improved. .
According to the fifth invention, since the piping lengths from the discharge ports of the plurality of pressure oil supply / discharge cylinders to the press cylinder are equal, the hydraulic oil supply time is the same among the pressure oil supply / discharge cylinders, Therefore, the controllability is improved.
According to the sixth aspect of the invention, the hydraulic oil can be replenished from the oil storage device, so that a large flow rate of the hydraulic oil necessary for high-speed pressurization can be supplied.
According to the seventh invention, since the oil storage device is located in the vicinity of the press cylinder, the pipe length can be shortened without replenishing oil from the hydraulic unit in the distant pit, and oil leakage and pressure loss are reduced. Can be made.

It is a front view of the hydraulic press concerning one embodiment of the present invention. It is a top view of the hydraulic press of FIG. It is an expanded sectional view of a press cylinder. It is sectional drawing at the time of contraction of a pressure oil supply / discharge cylinder. It is the VV line expanded sectional view in FIG. It is sectional drawing at the time of the expansion | extension of a pressure oil supply / discharge cylinder. It is a hydraulic circuit diagram in the hydraulic press of FIG.

Next, an embodiment of the present invention will be described with reference to the drawings.
Based on FIGS. 1 and 3, the basic structure of a hydraulic press to which the present invention is applied will be described first.
The hydraulic press is a press that performs molding of a molded product using hydraulic pressure. Examples of the molding process of the molded product include forging, drilling, bending, and correction. The hydraulic press includes a press main body P and a forming operation hydraulic cylinder (hereinafter referred to as a main cylinder) 10.

  The press main body P is comprised from the bed 1, the crown 2, and the upright 3 which connects these similarly to the well-known press. Note that the press main body P may have another configuration (for example, the one corresponding to the crown 2 or the upright 3 is an integrated structure).

The main cylinder 10 includes a cylinder body 11 and a cylinder rod 12 slidably inserted in the cylinder body 11 (see FIG. 3). The cylinder body 11 is attached to the crown 2 which is a part of the press body.
The main cylinder 10 is provided with a molding portion that performs a molding process of the molded product. That is, the slide 4 is attached to the lower part of the cylinder rod 12, and the upper die 5 is attached to the lower part via the die holder. The die holder and the upper die correspond to a forming part that performs a forming process of the product to be formed. On the other hand, a lower mold 6 is installed on the upper portion of the bed 1 via a die holder.

  The hydraulic press to which the present invention is applied includes not only the main cylinder 10 but also other hydraulic cylinders such as sub cylinders. The “press cylinder” referred to in the claims means one in which another hydraulic cylinder such as a sub cylinder is added to the main cylinder.

An outline of the press cylinder will be described with reference to FIG.
The structure of the main cylinder 10 can be arbitrarily selected from known structures, but the illustrated embodiment is a two-stage parent-child cylinder structure. The cylinder body 11 is integrally formed with a first cylinder 11A having a small diameter and a second cylinder 11B having a larger diameter that is larger than the first cylinder 11A. The cylinder rod 12 is integrally formed with a first cylinder rod 12A having a small diameter and a second cylinder rod 12B having a larger diameter that is larger than the first cylinder rod 12A. The inner diameter of the small first cylinder 11A and the outer diameter of the small first cylinder rod 12A are substantially the same, and the inner diameter of the large second cylinder 11B and the outer diameter of the large second cylinder rod 12B are substantially the same. It is the same.

  The space between the first cylinder 11A and the first cylinder rod 12A is a small oil chamber 10a, and the space between the second cylinder body 11B and the second cylinder rod 12B is a large oil chamber 10b. The first cylinder 11A is provided with a supply / discharge port 15 so that the small oil chamber 10a is connected to the outside, and the supply / discharge port 16 is provided in the second cylinder 11B so that the large oil chamber 10b is connected to the outside. . The supply / discharge port 15 and the supply / discharge port 16 are connected to a pressure oil supply / drainage unit OD and an oil storage unit 40 described later.

  In the main cylinder 10, if the cross-sectional area ratio between the first cylinder 11A and the second cylinder 11B is different, high speed driving and high load driving are performed depending on whether the hydraulic oil is supplied to the small oil chamber 10a or the large oil chamber 10b. And can be switched. At high speed and low load far from the bottom dead center, hydraulic pressure is applied to the first cylinder rod 12A having a small cross-sectional area by supplying hydraulic oil to the small oil chamber 10a, and the cylinder rod 12 can be driven at high speed. In addition, pressurization at low speed and high load near the bottom dead center causes hydraulic pressure to be applied to the second cylinder rod 12 having a large cross-sectional area by supplying hydraulic oil to the large oil chamber 10b, generating high load even at low speed. Can be made. In addition, in pressurization at low speed and high load, hydraulic oil is supplied to the small oil chamber 10a in addition to the large oil chamber 10b, and hydraulic pressure is applied to both the second cylinder rod 12B and the first cylinder rod 12A. Good.

  As an example, assuming that (the cross-sectional area of the first cylinder 11A) :( the cross-sectional area of the second cylinder 11B−the cross-sectional area of the first cylinder 11A) = 1: 2, when hydraulic oil is supplied only to the small oil chamber 10a. Compared with the case where hydraulic oil is supplied only to the large oil chamber 10b, the speed at which the cylinder rod 12 moves is doubled. Further, when the hydraulic oil is supplied only to the large oil chamber 10b, the generated force (force that the cylinder rod 12 pushes the slide 4) is doubled compared to the case where the hydraulic oil is supplied only to the small oil chamber 10a. Can be.

Note that such control of the applied pressure is performed by a control unit (not shown).
By controlling the applied pressure as described above, it is possible to perform a press operation satisfying the speed and the applied pressure, but in order to do so, the fluctuation range of the supply oil amount proposed by the present invention can be increased. A pressure oil supply / discharge cylinder is suitable.

Further, the sub cylinder 50 and the like will be described with reference to FIG.
A sub cylinder 50 is attached to the inside of the slide 4. The sub-cylinder 50 includes a cylinder body 51 and a cylinder rod 52 that moves up and down slidably therein. The cylinder rod 52 also serves as a punch.

  A knockout cylinder 55 is provided above the sub-cylinder 50. A piston rod 57 is inserted into the cylinder body 56, and the piston rod 57 projects downward from the lower end of the cylinder rod 52. .

Next, characteristic portions of the hydraulic press in the present embodiment will be described with reference to FIGS. 1 and 2.
P is a press body, and four uprights 3 are arranged on the front, rear, left and right sides thereof. A pressure oil supply / discharge section OD is provided one by one on the side of the four uprights 3 in the left-right direction (that is, the entry / exit directions of the molded product).

  The pressure oil supply / discharge unit OD includes a servo motor M and a hydraulic pressure generation unit Pg that generates hydraulic pressure by driving the servo motor M. In the present embodiment, the hydraulic pressure generating part Pg is constituted by a cylinder-type pressure oil supply / drainage cylinder 20, which will be described in detail later.

  Each pressure oil supply / discharge part OD is attached to the press body P in an upright state. The “standing state” means a state in which the longitudinal direction of the pressure oil supply / discharge portion OD is substantially vertical. In the case of the present embodiment, the pressure oil supply / discharge portion OD is attached to the press body P in a state where the longitudinal direction (extension direction) of the pressure oil supply / discharge cylinder 20 which is the oil pressure generating portion Pg is substantially vertical. The pressure oil supply / discharge part OD is attached to the press body P by attaching one end side thereof to the crown 2. The pressure oil supply / discharge part OD may be attached to another part of the press body P, for example, may be attached to the upright 3.

  In the illustrated embodiment, as shown in FIG. 2, the pressure oil supply / discharge section OD is a pressure oil supply / discharge cylinder 20, and four are used. However, two, six, or eight may be used. The number is arbitrary as long as it is plural. In the illustrated embodiment, the pressure oil supply / discharge cylinder portions 20A and 20B are arranged on the front and rear sides on the material entry side (left side in the drawing), and the pressure oil supply and discharge cylinder portions 20C and 20D are arranged on the front and rear sides on the material delivery side (right side in the drawing). Is arranged.

  As shown in FIG. 1, an oil storage unit 40 is installed on the crown 2. As the oil storage unit 40, a pressurized tank or an accumulator is used. Although the oil storage part 40 is attached to the upper end of the main cylinder 10, you may attach it to the crown 2 via a support member.

The oil storage unit 40 is connected to the supply / discharge port 15 and the supply / discharge port 16 of the main cylinder 10 by piping or the like (see FIG. 7). When pressurizing at a high speed, a large flow rate of hydraulic oil is required. However, if hydraulic oil is supplied to the main cylinder 10 using the oil storage section 40, a required amount of hydraulic oil can be supplied quickly.
The piping system between the oil storage unit 40 and the main cylinder 10 will be described later with reference to FIG. 7, but since the oil storage unit 40 is located in the vicinity of the main cylinder 10, the pipe length can be shortened and oil leakage occurs. And pressure loss can be reduced.

Next, details of the pressure oil supply / discharge cylinder 20 will be described with reference to FIGS.
Reference numeral 21 denotes a guide cylinder, and a cylinder portion 22 is attached to the tip of the guide cylinder. Reference numeral 23 denotes a discharge port formed at the tip of the cylinder portion 22. Reference numeral 24 denotes a piston, in which a piston portion 25 and a rod portion 26 are integrally formed. The piston part 25 is inserted into the guide cylinder 21, and the rod part 26 is inserted into the cylinder part 22 in a liquid-tight manner. A portion surrounded by the rod portion 26 and the cylinder portion 22 is an oil chamber 20a.

  A linear guide 27 is provided between the inner periphery of the guide cylinder 21 and the outer periphery of the piston portion 25 so that the piston 24 moves forward and backward in a state where the rotation is restricted. Further, the piston portion 25 is provided with a nut portion 28.

A ball screw 29 is screwed into the nut portion 28, and a tip portion of the ball screw 29 is inserted into a cavity formed in the piston portion 25.
The base of the ball screw 29 is rotatably supported by a thrust bearing 31 and a radial bearing 32. On the other hand, a servo motor M and a speed reducer 36 are attached to the lower end of the guide cylinder 21, and an output shaft thereof is connected to the ball screw 29 by a coupling 37.

Based on the above configuration, when the servo motor M is rotated forward and backward, the ball screw 29 is rotated forward and backward, the piston 24 moves forward and backward, and the rod portion 26 moves forward and backward in the cylinder body 22.
FIG. 4 shows a state in which the rod portion 26 is moving backward and the oil chamber 20a is filled with hydraulic oil. FIG. 6 shows a state in which the rod portion 26 has moved forward and hydraulic oil in the oil chamber 20a has been discharged.
By the action of the pressure oil supply / discharge cylinder 20, hydraulic oil can be supplied to and discharged from the press cylinder including the main cylinder 10.

The pressure oil supply / discharge cylinder 20 has a basic structure, and the discharge volume can be easily increased by increasing the diameter of the oil chamber 20a or increasing the length thereof. It is easy to increase the length.
The control of the discharge amount, that is, the control of the forward / reverse amount of the piston 24 can be achieved by controlling the integrated rotational amount of the servo motor M in the forward / reverse direction, and the control of the forward / reverse speed can be achieved by controlling the rotational speed (rpm). This can be achieved by controlling. Therefore, the pressure oil supply amount and the supply speed can be freely controlled.

Based on FIG. 7, the hydraulic circuit of the hydraulic press in the present embodiment will be described.
In the figure, four pressure oil supply / discharge cylinders are denoted by reference numerals 20A, 20B, 20C, and 20D.
A supply pipe 61 extending from the pump 60 is connected to the oil chambers 20a of the four pressure oil supply / discharge cylinders 20A to 20D. A discharge pipe 62 extends from each oil chamber 20a and is connected to a first supply / discharge pipe 63 and a second supply / discharge pipe 64, respectively. The first supply / discharge pipe 63 is connected to the small oil chamber 10a of the main cylinder 10, and the second supply / discharge pipe 64 is connected to the large oil chamber 10b.

The discharge pipe 62 is provided with an on-off valve or a pilot open check valve 65, so that the supply can be freely performed and the reverse flow is prevented but allowed to be performed by pilot control. Also, the same check valve is interposed in the first supply / discharge pipe 63 and the second supply / discharge pipe 64 (not shown) so that the hydraulic oil supply / discharge can be controlled.
Therefore, when the piston 24 of the pressure oil supply / discharge cylinders 20A to 20D is advanced to perform the discharge operation of pushing out the hydraulic oil in the oil chamber 20a, the small oil chamber 10a and the large oil chamber 10b of the main cylinder 10a are selectively or in parallel. Hydraulic oil can be supplied.

In addition, two supply pipes 66 and 67 are connected to the oil storage section 40. The supply pipe 66 is connected to a first supply / discharge pipe 63 communicating with the small oil chamber 10a, and the supply pipe 67 is connected to the large oil chamber 10b. It is connected to the. Further, a supply / discharge pipe 68 for returning the pressure oil to the oil storage section 40 is connected between the first supply / discharge pipe 63 and the oil storage section 40, and similarly, a supply / discharge pipe 69 is connected to the supply pipe 67 and the oil storage section 40. Connected between. These supply pipes 66 to 69 are also provided with pilot control type check valves that are not shown in the figure and that allow and prevent hydraulic oil supply and discharge.
For this reason, the hydraulic oil in the oil storage part 40 can be supplied to the small oil chamber 10a and / or the large oil chamber 10b of the main cylinder 10, and can be returned to the oil storage part 40.

  Note that the hydraulic oil supply / discharge to the sub cylinder 50 and the hydraulic oil supply / discharge to the knockout cylinder 55 use separate hydraulic sources 71 and 72 in the illustrated embodiment. Of course, 20A to 20D may be used.

As shown in FIG. 1, the first and second supply / discharge pipes 63 and 64 between the main cylinder 10 and the pressure oil supply / discharge cylinder 20 are connected to the main cylinder from the discharge port 23 at the upper end of the pressure oil supply / discharge cylinder 20a. 10 is connected to a hydraulic oil distribution block 70 provided at the upper end portion of the oil supply unit 10, and is distributed to the small oil chamber 10 a and the large oil chamber 10 b via the hydraulic oil distribution block 70.
If comprised in this way, the piping length from the pressure oil supply / discharge cylinder 20 to the main cylinder 10 will become short, and the delay time of hydraulic oil supply will become small. Moreover, since the pipe lengths are equal, the hydraulic oil supply time is the same between the pressure oil supply / discharge cylinders 20A to 20D, and there is no time variation of the hydraulic oil supply / discharge, thereby improving the controllability. Furthermore, the pipe length is shortened and oil leakage can be suppressed.

This embodiment has the following advantages.
1) By using a plurality of pressure oil supply / discharge cylinders 20 </ b> A to 20 </ b> D, a large flow rate of hydraulic oil can be sent to the main cylinder 10 at the same time. be able to.
2) By installing the pressure oil supply / discharge cylinder 20 upright, the planar installation space of the hydraulic unit can be significantly reduced.

3) Since the oil amount is directly controlled by the servo motor M, energy can be saved by reducing energy loss.
4) By installing a plurality of pressure oil supply / discharge cylinders 20A to 20D in the vicinity of the press cylinder (main cylinder 10 or the like), the volume of piping between the press cylinder (main cylinder 10 or the like) can be reduced. This leads to a reduction in the pressure loss due to oil leakage and further improves the response during pressurization.

5) Since the oil storage part 40 is located in the vicinity of the press cylinder (main cylinder 10 etc.), the pipe length can be shortened without replenishing oil from the hydraulic unit in the distant pit, Pressure loss can be reduced.

  The present invention is not limited to the above-described embodiments, and various modifications as described below are possible without departing from the gist of the present invention.

  In the above embodiment, the main cylinder 10 includes a cylinder body 11 in which a first cylinder 11A having a small diameter and a second cylinder 11B having a large diameter are integrally formed, and a cylinder rod that is slidably inserted into the cylinder body 11. However, other configurations may be used. For example, the cylinder body 11 may be composed of a cylinder having a single diameter and a cylinder rod slidably inserted into the cylinder.

  In the above embodiment, the pressure oil supply / discharge cylinder 20 is used as the hydraulic pressure generating part Pg, but a pump may be used instead. The pump receives rotation from a servo motor and discharges pressure oil by the rotation. That is, a known servo pump can be used.

  In the above embodiment, the press cylinder is fixed to the crown 2, but may be fixed to other parts of the press body. Moreover, although the hydraulic-oil discharge port of each pressure oil supply / discharge part OD is provided in the upper end, you may provide in the site | parts other than an upper end.

  In the above embodiment, the lengths of the pipes from the discharge port of the pressure oil supply / discharge part OD to the press cylinder are substantially equal, but those not equal are also included in the present invention.

  In the said embodiment, although the oil storage part 40 was provided, what does not have an oil storage part is also contained in this invention. Moreover, when providing an oil storage part, if it is a press main body, you may install in any members other than a crown.

1 Bed 2 Crown 3 Upright 4 Slide 10 Main cylinder 20 (20A, 20B, 20C, 20D) Pressure oil supply / discharge cylinder 22 Cylinder body 23 Discharge port 24 Piston 40 Oil storage part 50 Sub cylinder M Servo motor

Claims (7)

A hydraulic press having a press body and a press cylinder for molding work attached to the press body,
A pressure oil supply / discharge section driven by a servo motor for supplying hydraulic oil to the press cylinder;
A plurality of the hydraulic oil supply / discharge portions are provided, and each hydraulic oil supply / discharge portion is attached in a standing state on a side surface of the press main body. The press cylinder is
A cylinder body comprising: a first cylinder; and a second cylinder having an inner diameter larger than that of the first cylinder and formed integrally with the first cylinder;
The hydraulic press according to claim 1, further comprising a cylinder rod slidably inserted into the cylinder body. The pressure oil supply / discharge part is composed of a pressure oil supply / discharge cylinder comprising a cylinder part and a piston that advances and retreats in the cylinder part by rotation of the servo motor,
The hydraulic press according to claim 1 or 2, wherein the hydraulic oil supply / discharge cylinder is attached to a side surface of the press main body so that a longitudinal direction thereof is a vertical direction. The press body has a crown;
The press cylinder is fixed to the crown;
4. The hydraulic press according to claim 2, wherein each of the pressure oil supply and discharge portions is provided with a hydraulic oil discharge port at an upper end. The hydraulic press according to claim 3 or 4, wherein the length of the pipe from the discharge port of each pressure oil supply / discharge part to the press cylinder is substantially equal. The hydraulic press according to any one of claims 1 to 5, further comprising an oil storage section connected to the press cylinder. The hydraulic press according to claim 6, wherein the oil storage section is attached to the crown.

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