JP2000042689A - Device for molding mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a device for molding a mold having simple structure and small size. SOLUTION: Segment cylinders 109, 110 are parted into two chambers of a front chamber and a rear chamber with pistons 103, 104 sliding into the segment cylinders 109, 110 in segment cylinder devices 101, 102. In the front chamber and the rear chamber, non-compressive fluids 113, 116 are filled and front fluid chambers 111, 112 and rear fluid chambers 114, 115 are formed, and the front fluid chambers 111, 112 are mutually communicated through a communicated passage and also, the rear fluid chambers 113, 114 are mutually communicated through a communicated passage. Coil springs 107, 108 as energizing means, are interposed between the pistons 103, 104 and bottom cover bodies 105, 106 in the segment cylinder devices 101, 102.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a segment cylinder type mold making apparatus, and more particularly to a squeeze process in which a piston in each segment cylinder can take a free stroke position under a constant common pressure. The present invention relates to a simple mold making apparatus.

[0002]

2. Description of the Related Art As a mold making apparatus having a squeeze head of a segment cylinder type, a liquid line common to a segment cylinder group is communicated with a liquid tank and a liquid tank is connected between the common liquid line and the liquid tank. A switching valve, at least one level gauge in the liquid conduit liquid tank, a hydraulic cylinder device for squeezing against the segment cylinder group, and between the hydraulic cylinder device and the liquid cylinder liquid tank. One including a pump, a switching valve, and a check valve with a pilot is known (JP-A-51-148616).

[0003]

However, after the molding sand is supplied to the casting flask including the model, the squeezing process is advanced to a certain rate in the casting mold forming apparatus, and then the liquid pipeline and the liquid pipe are connected to the mold line. In order to complete the remaining squeezing process under the condition that the piston of each segment cylinder can take a free stroke position under a constant common pressure with the communication with the liquid conduit liquid tank being cut off, There is a problem that the maintainability of the apparatus is poor and the apparatus is enlarged. Then, this invention is made in order to solve such a problem, and makes it a subject to provide a simple structure and a small mold molding apparatus.

[0004]

According to a first aspect of the present invention, there is provided a mold making apparatus, wherein the interior of the segment cylinder is divided into a front chamber and a rear chamber by a piston sliding in the segment cylinder, and the front chamber and the rear chamber are separated. A plurality of segment cylinder devices filled with an incompressible fluid, and the front chambers communicate with each other, and the rear chambers communicate with each other. The mold forming apparatus according to the second aspect is the first aspect of the invention.
In the above described mold making apparatus, only the rear chamber is filled with the incompressible fluid instead of filling the front chamber and the rear chamber with the incompressible liquid. Claim 3
The mold forming apparatus according to claim 1, wherein the front chamber and the rear chamber are filled with the incompressible fluid only in place of filling the incompressible liquid into the front chamber and the rear chamber. It is characterized by. The mold molding apparatus according to claim 4, wherein the segment cylinder is divided into two chambers, a front chamber and a rear chamber, by a piston sliding in the segment cylinder, and the front chamber is filled with an incompressible liquid and the rear chamber is filled with the incompressible liquid. A plurality of segment cylinder devices having chambers communicating with the atmosphere are provided, and the front chambers communicate with each other. According to a fifth aspect of the present invention, there is provided the mold forming apparatus according to any one of the first to fourth aspects, wherein the urging means capable of moving the piston forward or backward is provided outside the front chamber, the rear chamber or the segment cylinder. It is characterized by being provided in. According to a sixth aspect of the present invention, the segment cylinder is divided into two chambers, a front chamber and a rear chamber, by a piston sliding in the segment cylinder, and the front chamber and the rear chamber communicate with each other. A biasing means for filling the incompressible fluid into the compartment and for moving the piston forward or backward;
A plurality of segment cylinder devices provided outside the rear chamber or the segment cylinder are provided, and the rear chambers communicate with each other.

According to the first aspect of the present invention, after the casting sand is supplied to the casting flask including the model, the squeezing process is advanced to a certain ratio in the process, and any one of the plurality of segment cylinder devices is provided. The segment cylinder device is pressed by the molding sand, and the piston of the segment cylinder device retreats. Thereby, the incompressible fluid in the rear chamber of the segment cylinder device flows out to the rear chamber of the other segment cylinder device, and the incompressible fluid in the front chamber of the other segment cylinder device includes the retracted piston. Into the front chamber of the segment cylinder device
An incompressible fluid flows between the front chambers and the rear chambers of each segment cylinder device that communicate with each other. When the squeeze process is further performed, all the segment cylinder devices are pressed by the molding sand, the flow of the incompressible fluid between the front chambers and the rear chamber is stopped, and the movement of all the pistons is stopped.

According to a second aspect of the present invention, after the casting sand is supplied to the casting frame including the model, the squeezing process is advanced to a predetermined ratio in the process, and any one of the plurality of segment cylinder devices is provided. The segment cylinder device is pressed by the molding sand, and the piston of the segment cylinder device retreats. Accordingly, the incompressible fluid in the rear chamber of the segment cylinder device flows out to the rear chamber of another segment cylinder device, and the gas in the front chamber of the other segment cylinder device is provided with the retreated piston. An incompressible fluid flows between the communicating rear chambers of each segment cylinder device while flowing into the front chamber of the device, and gas flows between the communicating front chambers of the segment cylinder device. When the squeeze process is further performed, all the segment cylinder devices are pressed by the molding sand, the flow of the incompressible fluid between the rear chambers is stopped, and the flow of the gas between the front chambers is stopped. Stop.

According to the third aspect of the present invention, after the casting sand is supplied to the casting flask including the model, the squeezing process is advanced to a predetermined ratio in the process, and any one of the plurality of segment cylinder devices is provided. The segment cylinder device is pressed by the molding sand, and the piston of the segment cylinder device retreats. Thus, the incompressible fluid flows from the front chamber of the other segment cylinder device into the front chamber of the segment cylinder device, and the gas in the rear chamber of the segment cylinder device having the retracted piston is removed by the other segment cylinder device. The incompressible fluid flows between the front chambers of each segment cylinder device which communicate with each other, and the gas flows between the rear chambers which communicate with each other of each segment cylinder device. When the squeeze process is further advanced, all the segment cylinder devices are pressed by the molding sand, the flow of the incompressible fluid between the front chambers is stopped, and the flow of the gas between the rear chambers is stopped. Stop.

According to the fourth aspect of the present invention, after the casting sand is supplied to the casting flask including the model, the squeezing process is advanced to a certain rate in the process, and any one of the plurality of segment cylinder devices is provided. The segment cylinder device is pressed by the molding sand, and the piston of the segment cylinder device retreats. Thereby, the incompressible fluid flows from the front chamber of the other segment cylinder apparatus into the front chamber of the segment cylinder apparatus, and the air in the rear chamber of the segment cylinder apparatus having the pressed piston is released into the atmosphere. The air is discharged and air flows into the rear chamber of the other segment cylinder device from the atmosphere. When the squeeze process is further advanced, all the segment cylinder devices are pressed by the molding sand, the flow of the incompressible fluid between the front fluid chambers is stopped, and the movement of all the pistons is stopped.

According to a fifth aspect of the present invention, when the pressing force of the molding sand applied to the piston of each segment cylinder device is released, the piston moves in the segment cylinder by the urging force of the urging means. In accordance with the movement of the piston, the incompressible fluid in the front chamber and / or the rear chamber flows between the front chambers and / or between the rear chambers of each segment cylinder, and the urging force and the piston of the segment cylinder device The piston stops in a state where the balance with the applied gravity is maintained.

According to a sixth aspect of the present invention, after the casting sand is supplied to the casting flask including the model, the squeezing process is advanced to a certain ratio in the process, and any one of the plurality of segment cylinder devices is provided. The segment cylinder device is pressed by the molding sand, and the piston of the segment cylinder device retreats. Thereby, the incompressible fluid in the rear chamber of the segment cylinder device flows out to the front chamber of another segment cylinder device, and the segment cylinder device having the pressed piston and the front and rear of each of the other segment cylinder devices. An incompressible fluid flows between the compartments. When the squeeze process is further advanced, all the segment cylinder devices are pressed by the molding sand, and the flow of the incompressible fluid between the rear chambers of the different segment cylinder devices and between the front and rear chambers of the same segment cylinder device stops, and all the pistons Stops moving. When the pressing force of the casting sand applied to the piston of each segment cylinder device is released, the piston moves in the segment cylinder by the urging force of the front chamber, the rear chamber or the urging means provided outside the segment cylinder, With the movement of the piston, the incompressible fluid in the rear chamber flows between the rear chambers of each segment cylinder, and the incompressible fluid flows between the front chamber and the rear chamber of each segment cylinder device. The piston stops while the balance between the urging force and the gravity applied to the piston of the segment cylinder device is maintained.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION A mold making apparatus may be provided with only one group of segment cylinder devices or a plurality of groups that communicate the front and / or rear chambers of a plurality of segment cylinder devices. As the incompressible fluid, a liquid in which various additive particles and the like are mixed in a liquid, in addition to a liquid alone such as oil and water, can be used. As the biasing means, a spring member such as a coil spring or a plate spring, a rubber member, an air spring, or the like can be used.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, a molding cylinder device 2
Is fixed, a table 4 is fixed on a piston rod 3 of a molding cylinder device 2, and a casting frame 6 is disposed on a model table 5 fixed to the table 4. A model 7 is disposed on the model table 5 inside the flask 6, and a molding sand 8 is filled in the flask 6 so as to bury the model 7. A pair of frames 9 are erected on both sides of the molding cylinder device 2, and a segment cylinder support member 10 laid between the frames 9 is erected above the casting frame 6. The cylinder device groups 11 and 12 are attached.

The segment cylinder device group 11 includes segment cylinder devices 13 and 14, an upper communication path 15a communicating the upper portion of the segment cylinder device 13 with the upper portion of the segment cylinder device 14, the lower portion of the segment cylinder device 13 and the segment cylinder device. And a lower communication passage 15b communicating with a lower portion of the device 14, and the segment cylinder group 12 includes segment cylinder devices 16, 17
An upper communication passage 18 that communicates between an upper portion of the segment cylinder device 16 and an upper portion of the segment cylinder device 17;
It is formed of a lower communication passage 19 that communicates a lower portion of the segment cylinder device 16 and a lower portion of the segment cylinder device 17.

Since the segment cylinder group 11 and the segment cylinder group 12 have the same configuration, the segment cylinder group 11 will be described below. FIG.
As shown in FIG.
Segment cylinder bodies 20, 21 and bottom lids 22, 2
3 and segment pistons 24, 25 sliding in the segment cylinders 24, 25.
7 and a front chamber 2 defined by pistons 26 and 27
8, 29 and the rear chambers 30, 31 are incompressible fluids 32, 3
Front fluid chambers 34, 35 and rear fluid chamber 3
6, 37, piston rods 38, 39 connected to the pistons 26, 27 and passing through the bottom lids 22, 23 of the segment cylinders 24, 25;
39 are formed from pressurizing elements 40 and 41 connected to the lower end. Seal members (not shown) are provided around the side surfaces of the pistons 26 and 27, and the front fluid chambers 34 and 35 and the rear fluid chambers 36 and 37 are formed independently of each other. A sealing member (not shown) is interposed between sliding surfaces of the bottom lids 22 and 23 and the piston rods 38 and 39.

The front fluid chamber 34 of the segment cylinder device 13 and the front fluid chamber 35 of the segment cylinder device 14 communicate with each other through the lower communication passage 15b, and the rear fluid chamber 36 of the segment cylinder device 13 and the segment cylinder device 14 Is communicated with the rear fluid chamber 37 via the upper communication passage 15a.

A casting frame 6 and a model 7 are arranged on a model table 5,
After the casting sand 8 is supplied into the casting flask 6, the piston rod 3 is moved up to advance the squeezing process to a certain ratio in the process, and as shown in FIG. Then, the piston 27 is pressed by the molding sand 8 via the piston rod 39, and the piston 27 retreats (moves upward in FIG. 2). As a result, the inside of the rear fluid chamber 37 becomes positive pressure, the incompressible fluid 33 in the rear fluid chamber 37 flows out to the rear fluid chamber 36 of the segment cylinder device 13, and the front fluid chamber 3 of the segment cylinder device 14.
The inside of the cylinder 5 becomes a negative pressure, and the incompressible fluid 32 in the front fluid chamber 34 of the segment cylinder device 13 flows into the front fluid chamber 35 of the segment cylinder device 37.

As shown in FIG. 3, when the squeezing process is further advanced, the pistons 26 and 27 of the segment cylinder devices 13 and 14 are both pressed by the molding sand 8 via the pressurizers 40 and 41 and the piston rods 38 and 39. , The inside of the rear fluid chamber 36 also becomes positive pressure, and the incompressible fluid 32 between the front fluid chambers 34 and 35 and between the rear fluid chambers 36 and 37,
The distribution of 33 stops. When the squeeze process is continued, the entire rear fluid chambers 36, 37 of the segment cylinder devices 13, 14 become positive pressure PP, and the pistons 26, 27
, And the entire front fluid chambers 34 and 35 have a negative pressure PN, and the pistons 26 and 27 are drawn downward. 8 is pressed and the foundry sand 8 is compacted.

The resistance force applied to the piston rod 3 when the piston rod 3 is raised is measured, and the pressurizers 40 and 41 are measured.
Obtains the pressing force applied to the molding sand 8. As shown in FIG. 4, after the resistance force is maintained at a predetermined magnitude for a predetermined time to squeeze the molding sand 8, the piston rod 3 is lowered,
The pressing force applied by the molding sand 8 to the pressurizing elements 40 and 41 is eliminated, and the piston 2 in the segment cylinders 24 and 25 is removed.
In steps 6 and 27, the molding is completed while the piston rod 3 is held in the same state as when the piston rod 3 is held with the predetermined resistance. In the present embodiment, the resistive force applied to the piston rod 3 of the cylinder device 2 is detected to
41 acquires the pressing force applied to the molding sand 8, and the pressing force is applied to the front fluid chamber 3 of the segment cylinder devices 13 and 14.
4, 35, the rear fluid chambers 36 and 37, the upper communication path 15a or the lower communication path 15b can also be obtained by measuring the hydraulic pressure. In particular, by simultaneously measuring the hydraulic pressures at a plurality of sites, for example, the hydraulic pressures of the upper communication passage 15a and the lower communication passage 15b, the pressure can be obtained with high accuracy.

A second embodiment of the present invention will be described with reference to FIG. In the second embodiment, a segment cylinder group 50 having the same structure as the segment cylinder group 11 of FIG.
Front chambers 53, 54 of segment cylinder devices 51, 52
Is filled with gas, and the rear chambers 55 and 56 are filled with an incompressible fluid 57.
To form the fluid chambers 58 and 59. When the segment cylinder group 50 is mounted on the segment cylinder support member 10 in place of the segment cylinder groups 11 and 12 shown in FIG. 1 and the molding sand 8 is supplied into the casting flask 6, the squeezing process is advanced to a certain rate in the process. The piston 60 of the segment cylinder device 52 is pressed by the molding sand 8 via the pressurizer 61 and the piston rod 62, and the piston 60
Retreats. Thereby, the inside of the fluid chamber 59 becomes a positive pressure,
The incompressible fluid 57 in the fluid chamber 59 flows out to the fluid chamber 58 of the segment cylinder device 51, and the pressure in the front chamber 54 of the segment cylinder device 52 becomes negative, so that the gas in the front chamber 53 of the segment cylinder device 51 Flows into the front chamber 54 of the segment cylinder device 52. When the squeeze process is further advanced, the segment cylinder device 51,
The pressurizers 63 and 61 of 52 are pressed by the molding sand 8, the movement of the pistons 64 and 60 is stopped, and the flow of the incompressible fluid 57 between the fluid chambers 58 and 59 and the flow of gas between the front chambers 53 and 54 are stopped. And the segment cylinder device 5
The entire pressure in the fluid chambers 58 and 59 of the first and the 52 becomes positive pressure PP.

A third embodiment of the present invention will be described with reference to FIG. In the third embodiment, a segment cylinder group 65 having the same structure as the segment cylinder group 11 of FIG.
Rear chambers 68, 69 of segment cylinder devices 66, 67
Is filled with gas, and the front chambers 70 and 71 are filled with an incompressible fluid 72.
To form the fluid chambers 73 and 74. When the segment cylinder group 65 is attached to the segment cylinder support member 10 in place of the segment cylinder groups 11 and 12 shown in FIG. 1 and the molding sand 8 is supplied into the casting flask 6, the squeezing process is advanced to a certain ratio in the process. , The piston 75 of the segment cylinder device 67 is pressed by the molding sand 8 via the pressurizing element 76 and the piston rod 77, and the piston 75
Retreats. Thereby, the segment cylinder device 67
Is negative pressure, the incompressible fluid 72 in the fluid chamber 73 of the segment cylinder device 66 flows into the fluid chamber 74 of the segment cylinder device 67, and the rear chamber 69 of the segment cylinder device 67 When the pressure becomes positive, the gas in the rear chamber 69 flows into the rear chamber 68 of the segment cylinder device 66. Further squeezing process,
Pressurizers 78, 76 of segment cylinder devices 66, 67
Is pressed by the molding sand 8, the movement of the pistons 79, 75 is stopped, and the incompressible fluid 7 between the fluid chambers 73, 74 is removed.
The gas flow between the second and rear chambers 68, 69 is stopped, and the fluid chambers 73,
The whole inside 74 becomes the negative pressure PN.

A fourth embodiment of the present invention will be described with reference to FIG. The segment cylinder group 80 according to the fourth embodiment includes a segment cylinder device 82 and a segment cylinder device 83 which communicate with each other via a communication passage 81. The pistons 86, 87 sliding in the segment cylinders 84, 85 divide the inside of the segment cylinders 84, 85 into two chambers, namely, front chambers 88, 89 and rear chambers 90, 91.
89 is filled with an incompressible liquid 92 and fluid chambers 93, 94
Are formed. In the rear chambers 90, 91, communication holes 95, 96 communicating with the atmosphere are formed. When the segment cylinder group 80 is attached to the segment cylinder support member 10 instead of the segment cylinder groups 11 and 12 shown in FIG. 1, and the molding sand 8 is supplied into the casting flask 6, the squeezing process is advanced to a certain rate in the process. , The piston 87 of the segment cylinder device 83 is pressed by the molding sand 8 via the pressurizer 97 and the piston rod 98, and the piston 87
Retreats. Thereby, the segment cylinder device 83
Becomes negative pressure, the incompressible fluid 92 in the fluid chamber 93 of the segment cylinder device 82 flows into the fluid chamber 94 of the segment cylinder device 83, and the rear chamber 91 of the segment cylinder device 83 The pressure in the rear chamber 91 becomes positive and the air in the rear chamber 91 flows out through the communication hole 96 to the outside. The pressure in the rear chamber 82 of the segment cylinder device 82 becomes negative and the external air flows through the communication hole 95 into the segment cylinder device 82. Into the rear chamber 90. When the squeezing process is further advanced, the pressurizing elements 99 and 97 of the segment cylinder devices 82 and 83 are pressed by the molding sand 8, the movement of the pistons 86 and 87 is stopped, and the incompressible fluid 92 between the fluid chambers 93 and 94 is moved. The circulation and the inflow and outflow of air in the rear chambers 90 and 91 are stopped, and the segment cylinder device 8 is stopped.
The whole inside of the fluid chambers 93, 94 of 2, 83 becomes negative pressure PN.

A fifth embodiment of the present invention will be described with reference to FIGS. The segment cylinder group 100 of the fifth embodiment includes:
2. Coil springs 107 and 108 are provided as urging means between pistons 103 and 104 and bottom lids 105 and 106 of segment cylinder devices 101 and 102 having the same configuration as segment cylinder device group 11 shown in FIG. It is. The operation of the segment cylinder group 100 when the segment cylinder group 100 is attached to the segment cylinder support member 10 instead of the segment cylinder groups 11 and 12 shown in FIG.
This is the same until the pressurization is completed. After the pressurization of the molding sand 8 is completed, as shown in FIG. 8, when the piston rod 3 is lowered, the pressing force applied to the pressurizing elements 117 and 118 by the molding sand 8 disappears, and the coil springs 107 and 108 are attached. The pistons 103 and 104 move in the segment cylinders 109 and 110 by the force. As a result, as shown in FIG. 9, the incompressible fluid 113 in the front fluid chambers 111 and 112 is moved by the movement of the pistons 103 and 104 to the front fluid chambers 11 of the segment cylinder devices 101 and 102.
1 and 112, and the rear fluid chambers 114 and 1
The incompressible fluid 116 in the fluid 15 flows between the rear fluid chambers 114 and 115 of the segment cylinder devices 101 and 102, and the urging force of the coil springs 107 and 108 and the gravity applied to the pistons 103 and 104 of the segment cylinder devices 101 and 102. Piston 10 in a state where
3, 104 stops.

A sixth embodiment of the present invention will be described with reference to FIGS. Segment cylinder group 130 of the sixth embodiment
Consists of a segment cylinder device 132 and a segment cylinder device 133.
The inside of the segment cylinders 135 and 136 of 2, 133
The front chambers 139 and 140 and the rear chambers 141 and 142 are partitioned by the pistons 137 and 138, and the rear chambers 141 and 142 are separated.
Reference numeral 42 communicates via the communication passage 131. Piston 1
37, 138, communication holes 143 for communicating the front chambers 139, 140 and the rear chambers 141, 142 with each other;
144 are formed, the front chambers 139, 140 and the rear chamber 1
The incompressible fluid 145 is filled in 41 and 142 to form front fluid chambers 147 and 148 and rear fluid chambers 149 and 150. The segment cylinder group 11 shown in FIG.
A segment cylinder group 130 is attached to the segment cylinder support member 10 in place of the
When the squeezing process is advanced to a certain ratio after the supply, the piston 138 of the segment cylinder device 133 is pressed by the molding sand 8 via the pressurizer 151 and the piston rod 152 as shown in FIG. 138 retreats. When the piston 138 retracts, the pressure in the rear fluid chamber 150 becomes positive, and the incompressible fluid 145 in the rear fluid chamber 150 flows out into the rear fluid chamber 149 of the segment cylinder device 132 and the rear portion of the segment cylinder device 133. Incompressible fluid 1 in fluid chamber 150
45 is the segment cylinder device 1 through the communication hole 144.
The incompressible fluid 145 in the front fluid chamber 147 of the segment cylinder device 132 flows into the rear fluid chamber 149 of the segment cylinder device 132 through the communication hole 143. . When the squeeze process is further advanced, as shown in FIG. 11, the pressurizers 153, 151 of the segment cylinder devices 132, 133
Is pressed by the molding sand 8, the movement of the pistons 137, 138 is stopped, the flow of the incompressible fluid 146 between the rear fluid chambers 149, 150 is stopped, and the rear fluid chambers 149, 150 of the segment cylinder devices 132, 133 are stopped. The whole becomes positive pressure PP.

A seventh embodiment of the present invention will be described with reference to FIG. The segment cylinder group 120 of the seventh embodiment includes pistons 103, 104 and bottom lids 105, 10 like segment cylinder devices 101, 102 shown in FIGS.
6 and the pistons 121 and 122 and the segment cylinder 1 instead of interposing the coil springs 107 and 108 between them.
Coil springs 127 and 128 are interposed between the ceiling surfaces 125 and 126 of the reference numerals 23 and 124. The segment cylinder device group 120 has the same operation and effect as the segment cylinder group 100 shown in FIGS.

An eighth embodiment of the present invention will be described with reference to FIG. The segment cylinder group 160 of the eighth embodiment includes pistons 103, 104 and bottom lids 105, 10 like segment cylinder devices 101, 102 shown in FIGS.
6, the coil springs 167, 168 are interposed between the bottom lids 163, 164 of the segment cylinder devices 161, 162 and the pressurizers 165, 166 instead of interposing the coil springs 107, 108 therebetween. It was done. The segment cylinder device group 160 has the same operation and effect as the segment cylinder group 100 shown in FIGS.

[0026]

According to the mold making apparatus of the present invention,
In a closed system formed by a plurality of segment cylinder devices communicating with each other, the piston in each segment cylinder takes a free stroke position under a constant common pressure and performs a squeeze process, so that the fluid chamber has an incompressible A supply system or the like for supplying the fluid is not required, so that the structure can be simplified and the device can be downsized. In particular, in the mold making apparatus according to the present invention, the pressing force applied from the molding sand to the piston of the segment cylinder device is a positive pressure generated in the rear chamber of the segment cylinder device and a negative pressure generated in the front chamber of the segment cylinder device. The piston in the segment cylinder is stopped in a state equal to the sum of the pressure and the pressing force applied to the piston is received on the entire inner wall surface of the segment cylinder. The cylinder can be made thinner. Further, in the mold molding apparatus according to claims 5 to 6, since each segment cylinder device has an urging means capable of moving the piston forward or backward, when the pressing force transmitted from the molding sand to the piston is released, the piston is quickly moved. To return to the initial setting position, the space secured under the segment cylinder device for inserting and removing the flask can be reduced.

[Brief description of the drawings]

FIG. 1 is a front view of a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part of the first embodiment at an initial stage of squeezing.

FIG. 3 is an enlarged sectional view of a main part during squeezing of the first embodiment.

FIG. 4 is an enlarged sectional view of a main part after squeezing of the first embodiment.

FIG. 5 is an enlarged sectional view of a main part of the second embodiment.

FIG. 6 is an enlarged sectional view of a main part of a third embodiment.

FIG. 7 is an enlarged sectional view of a main part of a fourth embodiment.

FIG. 8 is an enlarged cross-sectional view of a main part at the end of squeezing in the fifth embodiment.

FIG. 9 is an enlarged sectional view of a main part after completion of squeezing in the fifth embodiment.

FIG. 10 is an enlarged sectional view of a main part of a squeeze start stage of a sixth embodiment.

FIG. 11 is an enlarged sectional view of a main part during squeezing of the sixth embodiment.

FIG. 12 is an enlarged sectional view of a main part of a seventh embodiment.

FIG. 13 is an enlarged sectional view of a main part of an eighth embodiment.

[Explanation of symbols]

 13, 14, 16, 17 Segment cylinder device 15a Upper communication path 15b Lower communication path 24, 25 Segment cylinder 26, 27 Piston 28, 29 Front chamber 30, 31, Rear chamber 32, 33 Incompressible fluid 107, 108 Coil spring

Claims (6)

[Claims] 1. A segment cylinder device in which a segment cylinder is divided into a front chamber and a rear chamber by a piston which slides in the segment cylinder, and the front chamber and the rear chamber are filled with an incompressible fluid. A mold molding apparatus, comprising a plurality of the front chambers communicating with each other and the rear chambers communicating with each other. 2. The mold molding apparatus according to claim 1, wherein said front chamber and said rear chamber are filled with said incompressible fluid only in said rear chamber instead of filling said incompressible liquid. Mold making equipment. 3. The mold molding apparatus according to claim 1, wherein the front chamber and the rear chamber are filled with the incompressible fluid only in the front chamber, instead of being filled with the incompressible liquid. Mold making equipment. 4. The segment cylinder is divided into a front chamber and a rear chamber by a piston sliding in the segment cylinder, and the front chamber is filled with an incompressible liquid and the rear chamber is communicated with the atmosphere. A plurality of segment cylinder devices, and the front chambers communicate with each other. 5. The mold molding apparatus according to claim 1, wherein the urging means capable of moving the piston forward or backward is provided in the front chamber,
A mold forming apparatus provided outside the rear chamber or outside the segment cylinder. 6. The interior of the segment cylinder is divided into two chambers, a front chamber and a rear chamber, by a piston which slides in the segment cylinder. The front chamber and the rear chamber communicate with each other and the front chamber and the rear chamber. The front chamber is filled with an incompressible fluid, and a biasing means capable of moving the piston forward or backward is provided in the front chamber,
A mold molding apparatus comprising a plurality of segment cylinder devices provided outside the rear chamber or the segment cylinder, and the rear chambers communicate with each other.