JPS6345287Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of a bellows that forms an airtight chamber in a vacuum brick molding machine.

[Prior Art] The present applicant has already developed a technique for improving molding efficiency by forming an airtight chamber around a mold or punch and reducing the pressure inside when compression molding raw materials such as bricks. It has been proposed (see Utility Model Application Publication No. 53-117561).

The general structure of this kind of vacuum brick forming machine is:
5 and 6, upper and lower punches 2 and 3 are inserted into the mold 1, and the upper punch 2 descends together with the upper frame 4 to form the mold. Sandwich the raw materials filled in 1,
A brick molded product is obtained by pressure forming between the lower punch 3 and the lower punch 3. Cart 6 on which mold 1 is placed
The rails 8 disposed above both sides of the lower frame 7 can be moved by rollers 15. After completing the pressure forming, the cart 6 is moved to the side by the center D from the center line of the upper and lower punches, and at this position, the lower punch 3 is pushed up by an external force such as a drive cylinder, and the finished product is molded into the mold 1. After the raw material is extracted upward and moved elsewhere, and after receiving a fixed amount of raw material, the cart 6 is moved into the press body again.

In order to create a vacuum inside the mold 1 during pressure molding, the upper end of an expandable bellows 9 that surrounds the upper punch 2 is fixed to the lower side of the upper frame 4, and a sealing bellows 9 is attached to the lower end of the bellows 9. A ring 10 is attached.

This sealing ring 10 is connected to the drive cylinder 1.
1 to drive it up and down.

On the other hand, in the truck 6, a lower bellows 12 surrounds the lower punch 3 on the lower side thereof, and a sealing ring 13 attached to the lower end of the lower bellows 12 moves the drive cylinder 14 up and down with respect to the upper surface of the lower frame 7. It is set as. Then, the upper and lower bellows 9, 1 at the center of the upper and lower frames 4, 7
Ventilation ports 16 and 17 are provided at positions communicating with vacuum sources 18 and 19, and both ports communicate with vacuum sources 18 and 19. Note that parts that require airtightness, such as the surface facing the sealing ring, are sealed with a gasket 20 or the like.

Since the vacuum brick molding machine is configured as described above, in the molding process, the drive cylinder 1
1 is driven to press the sealing ring 10 onto the upper surface of the mold 1 to define an upper hermetic chamber 21 around the upper punch 2. Similarly, the lower drive cylinder 14 is operated to lower the sealing ring 13, and the lower punch 3 is lowered.
A lower airtight chamber 22 is defined around the . At this time,
The upper and lower bellows 9, 12 are in an extended state, but in the case of the upper bellows 9 in particular, the stroke of the upper punch 2 is long, so the overall length of the bellows is also large. In this state, the upper and lower airtight chambers 21 and 22
When the pressure inside the bellows 9 and 12 is reduced, a force acts on the bellows 9 and 12 to deform them inward due to the pressure difference between the inside and outside. As mentioned above, the bellows 9 and 12 need to be able to expand and contract in the axial direction of the punch, so they are made of a flexible material such as rubber, but they cannot resist the pressure difference and deform. Inconveniences arise in that the pressure in the airtight chamber cannot be sufficiently reduced.

Therefore, instead of the bellows, it has been proposed to use a skirt made of a soft material or a diaphragm made of a metal material to form an airtight chamber. Skirts and diaphragms have good pressure resistance in terms of structure, but it is difficult to increase the amount of expansion and contraction in the axial direction, and there are also problems in terms of service life due to repeated expansion and contraction.

Recently, larger dimensions of molded products have been required, and molding thicknesses that used to be around 150 mm are now required to be 500 mm or more.

In order to form an airtight chamber around a punch having such a long stroke, a bellows type punch is advantageous, and a bellows with high durability and pressure resistance has been desired.

Regarding the bellows, for example, the bellows disclosed in Japanese Patent Application Laid-Open No. 48-44307 is deformed inward due to the pressure difference between the inside and outside of the bellows, as described above, and cannot be restored. Furthermore, if a thick rubber or metal membrane is used to increase strength, the length when contracted becomes longer and the effective stroke becomes shorter.

Further, Japanese Utility Model Publication No. 48-41476 discloses a bellows for pressure detection in which a rubber membrane is stretched up to the peripheral edge of a metal bellows and caulked with a crimping ring. Although this bellows is not for vacuum chambers,
When used in a vacuum chamber, the contact surfaces of the bellows, rubber membrane, and caulking ring are all flat, so it is difficult to securely fix them and the pressure resistance is low.

[Object of the invention] Therefore, the object of the invention is to provide a bellows with good elasticity and high pressure resistance in a vacuum brick forming machine.

[Structure of the invention] According to the invention, in a vacuum brick forming machine equipped with an airtight chamber around a punch that moves up and down, the airtight chamber is formed by a plurality of bellows made of a membrane surface and having an annular protrusion protruding from the periphery. The bellows unit is formed by a rib having an annular groove carved therein, which connects the peripheral edge of the bellows unit by sandwiching it therebetween.

[Effects of the invention] The bellows are formed by reinforcing the periphery of the bellows unit, which is made of a flexible membrane surface, by sandwiching and connecting them with ribs, so it has good elasticity, and the annular groove of the bellows unit can be fitted into the annular groove of the rib. Since it is securely fixed, it has high pressure resistance.

In carrying out the invention, the connecting ribs are preferably arranged at the outer edge or at the outer and inner edges of the bellows unit.

[Example] An embodiment of the present invention will be explained below in FIG.

A vacuum brick molding machine embodying the present invention is shown in FIGS. 1a and 1b, and as in the conventional example, an upper punch 31 is attached to an upper frame 30, which works together with a lower punch 33 to form a mold. Pressure forming of the brick material in 32 is performed.

A seal packing 3 is provided on the lower surface of the upper frame 30.
A fixing ring 34 is attached via 5. A fixing rib 36 is provided on the lower surface of the fixing ring 34 to attach the bellows unit 3 made of a membrane surface body according to the present invention.
The outer edge 37b of 7a is fixed.

In FIG. 4, an annular projection A is formed on the upper and lower sides of the outer edge portion 37b, and an annular groove B into which the annular projection A is fitted is formed in the fixing rib 36 and the fixing ring 34. The bellows unit 37a and the fixing ring 36 are fixed to the fixing ring 34 with bolts 60.

The inner edge 37c of the bellows unit 37a overlaps the inner edge 37c of the next adjacent unit.
It is fixed with two ribs 38 and 39. and,
The outer edge 37d of this bellows unit 37a is further overlapped with the outer edge 37d of the next adjacent unit and fixed by two ribs 40, 41.

These fixings are explained with respect to the outer edges as shown in FIG. ing.

Connect the bellows units in the same way,
The lowermost unit is secured to the upper sealing ring 42 by a securing rib 36. This sealing ring 42 is attached to a piston rod 43a of a drive cylinder 43 and moves up and down. Also, this sealing ring 42
A seal packing 44 is inserted into the lower end of the
Airtightness between the mold 32 and the mold 32 is maintained. Since this embodiment is constructed as described above, in the molding process, the cylinder 43 is operated as shown in FIG. An airtight chamber 45 is formed around 31.

The inside of this hermetic chamber 45 is communicated with a vacuum source, and the pressure inside the hermetic chamber 45 is reduced. Therefore, pressure from the outside is applied to the bellows forming the airtight chamber 45.
However, the bellows unit has three ribs on the inside.
8 and 39 are tightened and reinforced on the outside by ribs 40 and 41, so that the shape of the airtight chamber 45 is maintained and reduced pressure is maintained without deforming even in response to external pressure.

In this embodiment, even if the stroke of the punch 31 becomes long, it is only necessary to add a bellows unit, and a durable airtight chamber can be obtained while ensuring elasticity. Next, in another embodiment of the present invention shown in FIG. 2, bellows units 50a made of membrane face members are connected only on the outside by rib members that also serve as reinforcement. That is, the upper end of the uppermost unit 50a has a protrusion 50
It is attached to the fixing ring 34 using a fixing rib 36 using bolts 60.

The other end 50c of the bellows unit 50a is joined back to back to the end 50c of the bellows unit 50a in the next stage, and is fixed with a bolt nut 61 between a pair of ribs 40 and 41.

The lowermost unit is attached to a sealing ring 42, which is actuated by a piston rod 43a of a cylinder 43. Therefore, during pressure molding, the piston rod 43a is extended to press the sealing ring 42 on the upper surface of the mold 32, and the upper punch 31 is pressed against the upper surface of the mold 32.
When the airtight chamber 51 is formed around the airtight chamber 51, even if the bellows 50a tries to deform due to external pressure, the reinforcing ribs 40 and 41 receive this pressure to prevent the bellows from deforming and ensure reduced pressure in the airtight chamber.

As described above, in this embodiment, the number of parts such as the bellows unit and ribs for connecting the units is reduced compared to the above-mentioned embodiment, and further cost reduction can be achieved.

In the above-mentioned embodiments, the bellows of the present invention is applied to the upper airtight chamber formed around the upper punch with a longer stroke, but the bellows of the present invention is applied to the lower airtight chamber formed around the lower punch. is also naturally applicable.

[Summary] As described above, in the present invention, a bellows unit made of a membrane surface made of rubber or the like is connected and reinforced with steel ribs, and an annular protrusion that fits into the annular groove of the rib is formed on the periphery of the unit, so that the molding thickness can be reduced. Even in the case of a large-sized press, a bellows can be prepared according to the stroke length of the punch, and deformation due to pressure differences can be reliably prevented.

[Brief explanation of the drawing]

1A and 1B are cross-sectional side views showing an embodiment of the present invention, FIG. 2 is a cross-sectional side view showing another embodiment, and FIGS. 3 and 4 are cross-sectional views showing a connecting portion of the bellows, 5 and 6 are side and front views of a conventional vacuum brick forming machine equipped with bellows. 31... Upper punch, 32... Mold, 33... Lower punch, 34... Fixed ring, 35... Seal packing, 36... Fixed rib, 37a... Bellows unit, 38, 39... Inner edge connection rib, 40, 41...
Outer edge connecting rib, 42... sealing ring, 43... actuator, 44... seal packing, 45... airtight chamber, 50a... bellows unit, 55... bellows, 60... bolt, 61... bolt nut.

Claims (1)

[Scope of utility model registration request] In a vacuum brick forming machine equipped with an airtight chamber around a punch that moves up and down, the airtight chamber is sandwiched between a plurality of bellows units, which are made of a membrane face and have annular protrusions protruding from the periphery, and the periphery of the bellows units is sandwiched. A bellows for a vacuum brick forming machine, characterized in that the bellows is formed from a rib having an annular groove carved therein and connected to the rib.