JPH0445866Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a mold clamping device for a direct pressure injection molding machine.
In particular, the present invention relates to a mold clamping device for a direct pressure injection molding machine, which comprises a mold feeding cylinder for opening and closing a mold, a mold feeding piston fitted therein, and a mold clamping cylinder fitted with a mold clamping piston integral with the mold feeding cylinder.

[Conventional technology]

The conventional technique will be explained using FIG. 5. A movable platen 2 is provided to slide on tie bars 3 installed on a fixed platen 1. A fixed side mold 4 is provided on the fixed platen 1,
A movable mold 5 is provided on the movable platen 2. tie bar 3
A mold clamping housing 6 is fixed to one end of the mold clamping housing 6, and a mold feeding cylinder 7 connected to the movable platen 2 is fitted into the mold clamping housing 6.

The mold clamping housing 6 has a mold clamping cylinder 9.
and a mold feeding piston 8 extending axially inside the mold feeding piston 8.
A mold clamping piston 10 integrally formed at the tip of the mold feeding cylinder 7 is fitted into the mold clamping cylinder 9, and a mold opening chamber 12 is formed between the mold clamping piston 10 and the mold clamping housing 6. Form. Further, a mold feeding piston 8 is fitted into a mold closing chamber 11 provided in the mold feeding cylinder 7.

The mold closing chamber 11 and the mold opening chamber 12 are connected to a hydraulic pressure source S via a mold feed valve 15. In addition, in the mold feeding valve 15, a is a mold opening position, b is a mold closing position, and c is a neutral position.

A mold clamping chamber 14 formed between the inner end surface of the mold clamping cylinder 9 and the mold clamping piston 10 communicates with a line P leading to a mold closing chamber 11 of a mold feed valve 15 via a mold clamping valve 16 . In addition, mold clamping valve 1
In 6, a ₁ is the mold closing position, b ₁ is the mold opening position, c ₁
is the neutral position. The mold clamping chamber 14 may be directly connected to the hydraulic pressure source S via the mold clamping valve 16.

Further, the mold clamping chamber 14 is provided with a prefill valve 1.
8 to the hydraulic oil tank 19a. The poppet 18a of this pre-fill valve 18 is connected to the pilot valve 1 of the pilot pressure source shown by the dotted line in FIG.
Control with 7. In this pilot valve 17, a ₂ is in the closed position and b ₂ is in the open position.

Next, to explain the operation of this device, in the mold closing process, hydraulic oil is sent from the hydraulic pressure source S to the mold closing chamber 11 via the line P through the position b of the mold feeding valve 15, and the hydraulic oil is sent to the mold closing chamber 11 through the line P. 7, the movable platen 2, and the movable mold 5 move forward toward the fixed platen 1 and the fixed mold 4.

At this time, the oil in the mold opening chamber 12 is discharged into the hydraulic oil tank 19 through the mold feed valve 15 at position b. At the same time, the pilot pressure passing through the open position _b2 of the pilot valve 17 opens the prefill valve 18, as shown by the dotted line in FIG.
The hydraulic oil a is sucked into the mold clamping chamber 14.

After this mold closing stroke, the pilot valve 17 is in the closed position _a2 and the prefill valve 18 is closed.

Thereafter, the mold clamping valve 16 is at the _a1 position, through which the pressure of the line P is transmitted into the mold clamping chamber 14, generating a mold clamping force.

In the mold opening process, hydraulic oil is sent from the hydraulic pressure source S to the mold opening chamber 12 via the position a of the mold feed valve 15, and the mold feed cylinder 7, the movable platen 2, and the movable mold 5
is retreated from the fixed platen 1 and fixed side mold 4. Further, the oil in the mold closing chamber 11 is discharged into the hydraulic oil tank 19 via the mold feed valve 15 at position a. On the other hand, at the same time, the pilot valve 17 goes to the open position _b2 , the prefill valve 18 opens, and hydraulic oil equal to the amount of movement of the mold feeding cylinder 7 is returned from the mold clamping chamber 14 to the hydraulic oil tank 19a.

[The problem that the idea aims to solve]

As described above, the amount of hydraulic oil that moves within the mold clamping chamber 14 when the prefill valve 18 opens is equal to the amount of movement of the mold feed cylinder 7, which is also proportional to the amount of movement of the mold clamping piston 10. Therefore, in order to generate mold clamping force, the diameter of the mold clamping piston 10 must be sufficiently large, but in this case, a large amount of hydraulic oil enters and exits the mold clamping chamber 14, and is used only for the purpose of transmitting pressure. It was a waste of resources to move a large amount of hydraulic oil only for the purpose of the mold, and this was a drawback of the direct pressure type mold clamping device. In other words, since a direct pressure injection molding machine generates a large force, the diameter of the clamping cylinder 9 is large, and therefore the diameter of the clamping piston 10 is also large, and the clamping piston 10 of the clamping cylinder 9 is also large by the mold feed stroke. Since the machine moves, a large amount of hydraulic oil must be put in and taken out of the mold clamping chamber 14, so a large amount of hydraulic oil is required compared to a toggle type injection molding machine.

[Means to solve the problem]

The present invention eliminates such drawbacks by providing a water reservoir chamber 13 in the mold clamping cylinder 9 and using water instead of a large amount of hydraulic oil.
The structure is such that the pressure of the hydraulic oil in the mold 4 is transmitted to the molds 4 and 5 to generate mold clamping force.

The present invention consists of a mold feeding cylinder 7 that opens and closes the molds 4 and 5, a mold feeding piston 8 fitted therein, and a mold clamping piston 10 provided on the side opposite to the mold of this mold feeding cylinder 7 and fitted therein. In a mold clamping device for a direct pressure injection molding machine that includes a mold clamping cylinder 9, the mold feeding cylinder 7 and the mold clamping piston 10 are configured separately, and the mold feeding piston 8 and the mold clamping piston 10 are integrally connected. The inside of the mold feeding cylinder 7 is divided into a mold closing chamber 11 and a mold opening chamber 12 by a mold feeding piston 8, and the mold closing chamber 11 and mold opening chamber 12 are connected to a hydraulic pressure source S via a mold feeding valve 15. Inside the mold clamping cylinder 9, a water reservoir chamber 13 and a mold clamping chamber 1 are created by the mold clamping piston 10.
The mold clamping chamber 14 is divided into mold clamping valve 16.
The water reservoir chamber 13 is connected to a water tank 20 via a water prefill valve 18.
The direct pressure type is characterized in that the fluid pressure in the mold clamping chamber 14 is transmitted to the stationary mold 4 and the movable mold 5 through water stored in the water reservoir chamber 13 during mold clamping. This is a mold clamping device for an injection molding machine.

[Effect]

During the mold opening operation, water in the water reservoir chamber 13 is discharged to the water tank 20 via the prefill valve 18,
During the mold closing operation, water from the water tank 20 is sucked into the water reservoir chamber 13 through the prefill valve 18, and during the mold clamping operation, the prefill valve 18 is closed and the water is transferred to the mold clamping chamber 1.
The pressure of the hydraulic oil sent to the mold 4 is transmitted to the molds 4 and 5 via the water in the water reservoir chamber 13 to generate mold clamping force.

〔Example〕

An embodiment of the present invention will be explained using FIGS. 1 to 4, with the same parts as in FIG. 5 being denoted by the same reference numerals, and different parts.

The mold feeding piston 8 is movably provided with respect to the mold clamping cylinder 9. The mold feed cylinder 7 and the mold clamping piston 10 are constructed separately, and the mold clamping piston 10
is integrally connected to the mold feeding piston 8.

The mold feeding piston 8 divides the inside of the mold feeding cylinder 7 into a mold closing chamber 11 and a mold opening chamber 12, and the mold closing chamber 11 and the mold opening chamber 12 each have two through holes 8a, 8b and a line extending inside the mold feeding piston 8. P and die feed valve 1
5 to the hydraulic pressure source S.

The clamping piston 10 divides the interior of the clamping cylinder 9 into a water reservoir chamber 13 and a clamping chamber 14 having a slightly smaller diameter. The mold feeding valve 15 communicates with a line P that reaches the mold closing chamber 11. Further, the water reservoir chamber 13 communicates with a water tank 20 via a prefill valve 18. The water tank 20 is filled with industrial water or water containing a non-staining liquid.

Next, the operation of this device will be explained.

Figure 1 shows when the machine is stopped with the mold open, and shows the mold feeding valve 15 and the mold clamping valve 16.
indicates the neutral position c, c ₁ , and the pilot valve 17
is the position _a2 where no pilot pressure acts on the poppet 18a of the profile valve 18.

FIG. 2 shows the mold in a closed state. In this state, as shown in FIG. 1, the mold feeding valve 15 is driven to the mold closing position a, and the pilot valve 17 is driven to the open position _b2 . As a result, the hydraulic oil is sent to the mold closing chamber 11 as shown in FIG. 2, and the molds 4 and 5 are closed as described above. On the other hand, the poppet 18a of the prefill valve 18 is opened by pilot pressure, and water is sucked into the water reservoir chamber 13 from the water tank 20. This is called the mold touch state.

Next, when the pilot valve 17 is returned to the closed position _a2 from the mold touching state shown in FIG. 2, the poppet 18a of the prefill valve 18 closes, and the water reservoir chamber 1
The water in 3 is sealed. Thus, the mold clamping valve 16
When the is driven to the mold clamping position _b1 , high pressure hydraulic oil from the hydraulic pressure source S is sent to the mold clamping chamber 14 from the line P, and the force of the high pressure hydraulic oil is transmitted through the mold clamping piston 10 and the water in the water reservoir chamber 13. The pressure is transmitted to the mold feed cylinder 7, the movable platen 2, and the movable mold 5, and generates pressure that pushes the molds 4 and 5 in the direction of tightening, thereby generating a mold clamping force.

The mold is opened using the mold feeding valve 15 as shown in Figure 4.
to the mold opening position b, the mold clamping valve 16 to the mold opening position _a1 , and the pilot valve 17 to the open position _b2 to open the poppet 18a of the prefill valve 18.
As a result, hydraulic oil is sent to the mold opening chamber 12, and the mold feeding cylinder 7, movable platen 2, and movable mold 5 move backward, while water in the water reservoir chamber 13 is supplied to the prefill valve 1.
8 and is discharged into the water tank 20, and the mold is opened as shown in FIG.

[Effect of idea]

As described above, the present invention uses water instead of a large amount of hydraulic oil by providing the water reservoir chamber 13 in the mold clamping cylinder 9, thereby saving hydraulic oil and creating a resource-saving direct pressure type mold clamping device. It is something that can be manufactured.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention in a neutral state, and FIG. 2 is a sectional view similarly showing a mold closed state.
FIG. 3 is a cross-sectional view showing the mold clamped state, FIG. 4 is a cross-sectional view showing the mold opening state, and FIG. 5 is a cross-sectional view of the conventional device. 7... Mold feeding cylinder, 8... Mold feeding piston, 9... Mold clamping cylinder, 10... Mold clamping piston, 13... Water reservoir chamber, 14... Mold clamping chamber, 4
... Fixed side mold, 5 ... Movable side mold, 16 ... Mold closing valve, 15 ... Mold feeding valve, 11 ... Mold closing chamber, 12 ... Mold opening chamber, 18 ... Prefill valve, 20 ……water tank.

Claims (1)

[Scope of utility model registration request] A direct pressure injection molding machine consisting of a mold feeding cylinder that opens and closes a mold, a mold feeding piston fitted into the mold feeding cylinder, a mold clamping piston provided on the side opposite to the mold of the mold feeding cylinder, and a mold clamping cylinder fitted with the mold feeding cylinder. In the mold clamping device, the mold feeding cylinder and the mold clamping piston are configured separately, and the mold feeding piston and the mold clamping piston are integrally connected, and the mold closing chamber and the mold opening chamber are controlled by the mold feeding piston inside the mold feeding cylinder. The mold closing chamber and the mold opening chamber are connected to a hydraulic pressure source via a mold feed valve, and the mold clamping cylinder is divided into a water reservoir chamber and a mold clamping chamber by this mold clamping piston. The clamping chamber communicates with the hydraulic pressure source through a mold clamping valve, and the water reservoir chamber communicates with a water tank through a water prefill valve, so that the fluid pressure in the mold clamping chamber is stored in the water reservoir chamber during mold clamping. A mold clamping device for a direct pressure injection molding machine, characterized in that the pressure is transmitted to a fixed side mold and a movable side mold through water.