JP6199763B2 - Double acting hydraulic press - Google Patents

Description

  The present invention relates to a double-acting hydraulic press. More specifically, the present invention relates to a double-acting hydraulic press that is used for closed forging or the like and includes a first cylinder that raises and lowers a slide and a second cylinder that applies pressure to a punch.

  Closed forging is a method in which an upper and lower mold and a punch are used, the upper and lower molds are clamped and the work is confined in the mold space, and then the punch is pushed into the work to fill the mold space. In this closed forging, a double-acting hydraulic press is used, and the upper and lower molds are clamped by the first cylinder, and the pressing force is applied to the punch by the second cylinder. Generally, in a double acting hydraulic press for closed forging, a second cylinder is provided on a slide that moves up and down by the operation of the first cylinder.

  In the conventional double-acting hydraulic press, in order to operate the second cylinder installed on the slide, a press frame including an oil tank and the slide are connected by a hose, and hydraulic oil is supplied to the second cylinder. Therefore, when a large press requires a high pressurization capacity for the second cylinder, or when it is necessary to increase the pressurization speed of the second cylinder, a large diameter so that high pressure and large flow rate of hydraulic fluid can flow. It is necessary to perform hose piping using a plurality of hoses or a plurality of small diameter hoses.

However, since the hose moves following the movement of the cylinder and the piston, the hose tends to deteriorate. In addition, since replacement of a deteriorated hose is time-consuming, the user desires to reduce the number of hoses connected to movable cylinders and pistons as much as possible.
For this reason, a double-action press device in which a hose is not connected to a movable cylinder or piston has been proposed (see Patent Documents 1 and 2).

The prior art of Patent Document 1 has a structure in which a cylinder is shared by two rams. That is, one cylinder is used, and the inner ram slides at the upper part thereof, and the outer ram slides at the lower part thereof. The hydraulic oil is supplied from the hydraulic pressure source to the cylinder by pipe piping, and the hydraulic oil is supplied to the individual oil chambers through the oil passage in the cylinder.
However, this prior art has the disadvantage that the inner ram becomes too long. In this case, in order to withstand a high force, it is necessary to make the inner ram thicker, which leads to a problem that the inner ram becomes longer and larger in diameter and the structure becomes larger.

The prior art of Patent Document 2 uses an oil passage formed in the cylinder from the oil chamber in the main cylinder to the oil chamber in the sub cylinder, but a valve block is interposed in the middle. The valve block is attached to the outer surface of the cylinder. Then, the opening and closing of the valve block is controlled to control the supply of hydraulic oil to the sub cylinder side.
However, in this prior art, a mechanism for controlling opening and closing of the valve is required, and the mechanism becomes complicated. In addition, since the oil passage once goes out of the cylinder by the valve block, there is a problem that if oil leakage occurs, it takes time to clean up, and thus means for preventing oil leakage is required.

JP-A-61-255796 JP 2011-156562 A

  SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a double-acting hydraulic press apparatus that can supply hydraulic oil with a simple configuration that does not use a hose between movable members and suppresses the lengthening of press parts. And

A double-acting hydraulic press according to a first aspect of the present invention includes a first cylinder fixed to a press body, a first cylinder rod slidably inserted along an inner peripheral surface of the first cylinder, and the first cylinder rod. A double-acting hydraulic press comprising a second cylinder fixed to the second cylinder rod and a second cylinder rod slidably inserted along the inner peripheral surface of the second cylinder, wherein the first cylinder has its head portion A first supply passage for supplying and discharging hydraulic oil from the outside to a first oil chamber between the first cylinder rod and the head of the first cylinder rod, an inner peripheral surface of the first cylinder, and an outer peripheral surface of the first cylinder rod And a second supply passage for supplying and discharging hydraulic oil from the outside to the connecting oil passage, and the first cylinder rod is connected to the communication oil passage. And communicates with the second cylinder side formed inside the rod. The second cylinder has a second oil chamber between the head portion and the head of the second cylinder rod, and the second oil chamber and the second oil chamber a first internal fluid passage to have a second inner fluid passage formed in the cylinder body of the second cylinder so as to communicate with, to form part of the communication oil passage in the first cylinder, the first cylinder rod A bush is slidably contacted with the oil passage, and an oil flow passage is formed in the bush to communicate the communication oil passage with the first internal oil passage .
In the double-acting hydraulic press of the second invention according to the first invention, the communication oil passage is formed by a recess formed in the inner peripheral surface of the first cylinder, and the recess is in the advancing and retracting direction of the first cylinder rod. It is formed by stretching.
Double action oil hydraulic press of the third invention, was first or the second aspect, the second inner oil passage, the cylinder body of the second cylinder, linearly so as to extend in the moving direction of the second cylinder rod It is formed in the shape.
A double-acting hydraulic press of a fourth invention is the double-acting hydraulic press according to the third invention, wherein the first internal oil passage is formed so as to extend on a central axis of the first cylinder rod, and the second internal oil passage is the second internal oil passage. It is characterized in that it is formed so as to extend in the advancing / retreating direction of the second cylinder rod at the center axis position of the cylinder.
A double-acting hydraulic press according to a fifth invention is characterized in that, in the first invention, the press main body has a crown at an upper end thereof, and the second supply path is provided above the crown. And

According to the first invention, the following effects are obtained.
a) The hydraulic oil can be supplied to the third oil chamber in which the second cylinder rod is operated by the first internal oil passage in the first cylinder rod and the second internal oil passage in the second cylinder. Therefore, the hydraulic oil supply to the second cylinder is moving parts so may not be used hoses, there is no risk of the hose deterioration or damage, it can be realized a simple press structure.
b) Since the outer periphery of the rod is held by the bush while the first cylinder rod is moving back and forth, the first cylinder rod is maintained in a concentric state despite the formation of a cavity serving as a communication oil passage. Can be advanced or retracted.
According to the second invention, even if the first cylinder rod advances and retreats, the communication oil passage can ensure the communication state between the second supply passage and the first internal oil passage, so that the pressurizing operation of the press is not hindered. Done.
According to the third aspect of the invention, the second internal oil passage passes through the shortest distance, and there is no valve or the like in the middle.
According to the fourth invention, since the first cylinder rod is cylindrical, it may rotate in the first cylinder, but even if rotation occurs, the first internal oil passage and the second internal oil passage are concentric. Since the communication state is maintained, the assembly work can be easily performed.
According to the fifth invention, since the second supply path is above the crown, it is easy to take up piping space, and maintenance management such as oil leak detection and maintenance work can be easily performed.

It is a principal part sectional front view of the double acting hydraulic press concerning one embodiment of the present invention. It is an expanded sectional view of the 1st cylinder 10 and the 2nd cylinder 20 which are shown in FIG. FIG. 3 is an enlarged view around a communication oil passage 30 and a bush 35 shown in FIG. 2. FIG. 3 is an exploded sectional view of a communication oil passage 30, a bush 35, and a first cylinder rod 12 shown in FIG. 2 is an enlarged cross-sectional view of a first cylinder 10 and a second cylinder 20 in an extended state. FIG.

Next, an embodiment of the present invention will be described with reference to the drawings.
Based on FIG. 1, the basic structure of a double-acting hydraulic press to which the present invention is applied will be described first.
The press main body is composed of a bed 1, a crown 2, and an upright 3 that connects them, similarly to a known press. The hydraulic cylinder for forging is composed of a first cylinder 10 called a main cylinder and a second cylinder 20 called a sub cylinder. The first cylinder 10 includes a first cylinder body 11 and a first cylinder rod 12 slidably inserted into the first cylinder body 11. The 1st cylinder body 11 is attached to the crown 2 which is a part of press body.

A second cylinder 20 is attached to the lower end of the first cylinder rod 12. The second cylinder 20 includes a second cylinder body 21 and a second cylinder rod 22 that moves up and down slidably therein. A slide is attached to the second cylinder body 21 and guided up and down by a slide guide provided in the press body.
A second cylinder rod 22 is inserted into the second cylinder body 21 so as to be slidable in the vertical direction, and the second cylinder rod 22 serves as a punch.

An upper die 5 is attached to a lower portion of the second cylinder body 21 to which the slide is attached via a die holder, and a lower die 6 is installed on the upper surface of the bed 3 via a die holder.
With the basic structure as described above, when the first cylinder rod 12 of the first cylinder 10 is lowered, the slide (and the second cylinder body 21) is lowered and the upper mold 5 and the lower mold 6 clamp the material. Then, when the second cylinder rod 22 of the second cylinder 20 is lowered, closed forging by punching can be performed.

Next, a hydraulic oil supply structure that is a characteristic part of the present invention will be described.
The hydraulic oil supply structure of the present invention is characterized in that a hose-less structure is achieved. The outline will be described with reference to FIG.
A space between the head portion of the first cylinder body 11 and the head of the first cylinder rod 12 is a first oil chamber 13, and a first supply path 14 for supplying and discharging hydraulic oil to and from the first oil chamber 13. Is formed in the head portion of the first cylinder body 11. A fixed pipe such as a pipe is used to supply the hydraulic oil to the first supply path 14.

A second supply passage 15 for supplying and discharging hydraulic oil to and from a communication oil passage 30 and a first internal oil passage 16 described later is formed on the side surface of the first cylinder body 11. A fixed pipe such as a pipe is also connected to the second supply path 15.
When the second supply path 15 is provided above the crown 2 as shown in FIG. 1, it is easy to take a piping space, and it is possible to easily perform maintenance management such as detection of oil leakage and maintenance work.

  A first internal oil passage 16 extending vertically is formed in the first cylinder rod 12 and on the central axis A of the rod. The first internal oil passage 16 includes a lateral oil passage 16 a that does not extend to the upper end portion of the first cylinder rod 12 and that extends sideways in the middle, and communicates with the second supply passage 15. The first internal oil passage 16 extends to the lower end of the first cylinder rod 12 and opens at the lower end surface.

A communication oil passage 30 is formed on the inner peripheral surface of the first cylinder body 11 in a substantially intermediate portion in the vertical direction.
Details about the communication oil passage 30 will be described with reference to FIGS. 3 and 4.
The communication oil passage 30 is an oil chamber provided in the form of forming a recess in the inner periphery of the first cylinder body 11, and is formed in an annular shape so that a plurality of longitudinal grooves 31 communicate with each longitudinal groove 31. It consists of three lateral grooves 32. Of course, the second oil supply passage 15 communicates with the communication oil passage 30. The communication oil passage 30 is formed by extending in the direction along the central axis A by a length corresponding to the stroke of the first cylinder rod 12. In addition, the vertical groove 31 and the horizontal groove 32 should just be an oil chamber which contact | connects the outer peripheral surface of the 1st cylinder rod 12, and the number etc. are arbitrary.

A bush 35 is attached to the inner periphery of the first cylinder body 11 where the communication oil passage 30 is formed as described above.
The bush 35 is a substantially cylindrical member, and a flange portion 35a for attachment is formed at the lower end portion thereof. The fixing to the first cylinder body 11 is performed by any means such as bolting through the flange portion 35a. An oil flow passage 38 is formed on the inner peripheral surface of the body portion of the bush 35.

  The oil flow passage 38 includes a through hole 36 penetrating in the vertical direction and an annular recess 37 which is a recess formed in the inner peripheral surface. A plurality of through-holes 36 are formed in a plurality of stages at intervals in the circumferential direction on the inner periphery of the bush 35. The annular recess 37 is a recess over the entire circumference, and the vertical dimension is substantially equal to the distance between the upper and lower stages of the through hole 36. That is, the oil flow passage 38 is formed to extend in the direction along the central axis A by a length corresponding to the stroke of the first cylinder rod 12. The oil flow passage 38 including the through hole 36 and the annular recess 37 communicates the communication oil passage 30 formed in the first cylinder body 11 with the first internal oil passage 16 of the first cylinder rod 12 to supply hydraulic oil. It is provided to eliminate.

The reason why both the connecting oil passage 30 and the oil flow passage 38 extend in the vertical direction is to allow the hydraulic oil to be supplied and discharged at any position where the first cylinder rod 12 has moved up and down.
In addition, the communication oil passage 30 and the oil flow passage 38 are formed in the annular direction so that the hydraulic oil supply is not hindered even if the first cylinder rod 12 rotates in the first cylinder body 11. Because.

  Although the first cylinder rod 12 moves back and forth up and down, the outer periphery of the rod is held by the inner periphery of the first cylinder body 11 above the communication oil passage 30 even in the state where the first cylinder rod 12 is moved down. For this reason, although the cavity used as the communication oil path 30 is formed, the 1st cylinder rod 12 can be advanced / retreated in the stable state, maintaining a concentric state.

Returning to FIG. 2, the details of the second cylinder 20 will be described.
The second cylinder 20 has a second oil chamber 23 in a space between the head portion of the second cylinder body 21 and the head of the second cylinder rod 22. The second cylinder body 21 is formed with a second internal oil passage 26 for supplying hydraulic oil to the second oil chamber 23. The second internal oil passage 26 extends vertically at the head portion of the second cylinder body 21. That is, the second cylinder rod 22 is formed in a straight line extending in the forward / backward direction. The upper end surface of the head portion of the second cylinder body 21 is opened, and the lower end surface, that is, the inner surface facing the second oil chamber 23 is also opened.

As shown in FIG. 2, the first internal oil passage 16 is formed so as to extend on the central axis A of the first cylinder rod 12, and the second internal oil passage 26 is also at the position of the central axis A of the second cylinder body 21. The two-cylinder rod 22 is formed so as to extend in the advancing and retracting direction.
For this reason, since the first cylinder rod 12 is cylindrical, the first cylinder rod 12 may rotate within the first cylinder body 11. However, even if rotation occurs, the first internal oil passage 16 and the second internal oil passage 26 are concentric. Therefore, the communication state can be maintained, and the assembly work can be easily performed.

  The first cylinder rod 12 is a two-stage outer rod whose lower portion is formed to have a larger diameter than the upper portion, and a large-diameter cylinder portion 11a having an enlarged inner diameter of the first cylinder body 11 and a shoulder portion of the large-diameter rod portion 12a. A first rod side oil chamber 17 is formed between them. A third supply path 18 is formed in the first cylinder body 11 to supply and discharge hydraulic oil to and from the first rod side oil chamber 17, and a fixed pipe such as a pipe is connected to the third supply path 18. It has become so.

  In the second cylinder 20, a space between the rod side of the second cylinder rod 22 and the second cylinder body 21 is a second rod side oil chamber 24, and hydraulic oil is supplied to the second rod side oil chamber 24. A fourth supply path 25 for discharging is formed on the side wall of the second cylinder body 21. The second rod side oil chamber 24 and the fourth supply path 25 are used when the second cylinder rod 22 is retracted.

Next, the operating procedure of the double-acting hydraulic press of this embodiment will be described.
(1) Pressurization operation FIG. 2 shows a state immediately before the pressurization operation.
In this state, when pressure oil is supplied from the first supply passage 14 to the first oil chamber 13 and pressure oil is supplied from the third supply passage 18 to the first rod side oil chamber 17, as shown in FIG. 1 cylinder rod 11 descends.
As a result, clamping is performed in which the material is pressurized with the upper and lower molds.

(2) Clamping operation Next, when pressure oil is supplied from the second supply passage 15, the pressure oil passes through the communication oil passage 30 and the oil flow passage 38 of the bush 35 (see FIG. 4), and the first cylinder rod 12 1 It is fed into the internal oil passage 16. Then, the hydraulic oil flows down the first internal oil passage 16 and is supplied to the second oil chamber 23 via the second internal oil passage 26. As a result, as shown in FIG. 5, the second cylinder rod 22 is lowered and the mold clamping is performed.

The advantages of the double-acting hydraulic press of this embodiment are as follows.
(1) Supply hydraulic oil to the second oil chamber 23 for operating the second cylinder rod 22 by the first internal oil passage 16 in the first cylinder rod 12 and the second internal oil passage 26 in the second cylinder body 21. it can. Thus, since it is not necessary to use a hose for supplying hydraulic oil to the possible portion, there is no fear of deterioration or damage of the hose, and a press with a simple configuration can be realized.
(2) Even if the first cylinder rod 12 advances and retreats, the communication state between the second supply passage 15 and the first internal oil passage 16 can be secured, so that the pressurizing operation of the press is performed without any trouble.
(3) Since the second internal oil passage 26 passes through the shortest distance and there is no valve or the like on the way, there is no inconvenience such as oil leakage, and the oil passage length is shortened, so that hydraulic oil can be supplied and discharged quickly. There is no delay in operation.
(4) Since the first cylinder 10 and the second cylinder 20 have the individual cylinder bodies 11 and 21, respectively, and the individual cylinder rods 12 and 22, it is avoided that one cylinder rod is lengthened. The structure can be simplified.

(Other embodiments)
Next, another embodiment of the present invention will be described.
(1) Although the bush 35 is provided in the embodiment, the bush 35 may not be provided. In this case, the second supply passage 15 and the first internal oil passage 16 may be communicated with each other by the communication oil passage 30 formed on the inner peripheral surface of the first cylinder body 11.
(2) Although the second supply path 15 is provided above the crown 2 in the embodiment, it may be provided below the crown 2, and such an embodiment is also included in the present invention.

(3) In the above embodiment, the first internal oil passage 16 is linear and located on the central axis A. However, the first internal oil passage 16 may not be linear and may be formed at a position shifted from the central axis A. Good.
Similarly, in the above embodiment, the second internal oil passage 26 is linear and positioned on the central axis A, but may be formed not at the linear shape but at a position shifted from the central axis A. For example, when a knockout cylinder is incorporated in the second cylinder 20, it is necessary to avoid the knockout cylinder that would be formed on the central axis A and to form the second internal oil passage 26. If the path 26 is bent halfway or passed through a place away from the central axis A, the second internal oil path 26 can be provided without difficulty.

DESCRIPTION OF SYMBOLS 10 1st cylinder 11 1st cylinder body 12 1st cylinder rod 15 2nd supply path 16 1st internal oil path 20 2nd cylinder 21 2nd cylinder body 22 2nd cylinder rod 26 2nd internal oil path 30 Communication oil path 35 bush

Claims (5)

A first cylinder fixed to the press main body, a first cylinder rod slidably inserted along an inner peripheral surface of the first cylinder, a second cylinder fixed to the first cylinder rod, A double-acting hydraulic press comprising a second cylinder rod slidably inserted along the inner peripheral surface of the second cylinder,
The first cylinder has a first supply path for supplying and discharging hydraulic oil from the outside to a first oil chamber between a head portion of the first cylinder and the head of the first cylinder rod, and an inner peripheral surface of the first cylinder. And a communication oil passage formed between the first cylinder rod and the outer peripheral surface of the first cylinder rod, and a second supply passage for supplying and discharging hydraulic oil from the outside to the connection oil passage,
The first cylinder rod has a first internal oil passage that communicates with the communication oil passage and extends to an end portion on the second cylinder side that is formed inside the rod;
The second cylinder has a second oil chamber between a head portion of the second cylinder and the head of the second cylinder rod, and the second oil chamber communicates with the first internal oil passage. 2 have a second inner fluid passage formed in the cylinder body of the cylinder,
A bush that slides on the first cylinder rod is attached to the formation portion of the communication oil passage in the first cylinder,
The double-acting hydraulic press according to claim 1, wherein an oil flow passage is formed in the bush to communicate the communication oil passage with the first internal oil passage . 2. The communication oil passage is composed of a recess formed in an inner peripheral surface of the first cylinder, and the recess is formed by extending in the advancing / retreating direction of the first cylinder rod. Double acting hydraulic press as described. The second inner oil passage, the cylinder body of the second cylinder, according to claim 1 or 2, wherein in that it is formed in a linear shape so as to extend in the moving direction of the second cylinder rod Double acting hydraulic press. The first internal oil passage is formed to extend on a central axis of the first cylinder rod;
The double-acting hydraulic press according to claim 3, wherein the second internal oil passage is formed so as to extend in a forward / backward direction of the second cylinder rod at a central axis position of the second cylinder. The double-acting hydraulic press according to claim 1, wherein the press body has a crown at an upper end thereof, and the second supply path is provided above the crown.

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