JPS6311323A - Apparatus for clamping of molding machine - Google Patents

Abstract

PURPOSE:To make a clamping part smaller and to obtain a defined clamping force with a smaller driving force, by providing a cam supported by a frame, contacting a contacting part and whose slope of the displacement curve is at first large and becomes smaller with progress of clamping. CONSTITUTION:The movable side mold 19 of a movable platen 12 is elevated by an air cylinder 13 to contact with a mold of the fixed side 18 and a cam 15 is pushed out by an air cylinder 17. A roller follower 14 is also pushed up and a defined clamping force is thereby generated. A molten resin or metal is injected from an injection nozzle 20 and is molded. The cam 15 is pulled back by the air cylinder 17 and the high pressure clamping is released. The movable platen 12 descends and opening of the mold is carried out. The part 15a of the cam 15 has a displacement curve represented by the equation (1) and the parts 15b and 15c have shapes represented by the equations (2) and (3). The cam 15 contacts the roller follower 14 at the part 15b and the contacted part moves to the part 15a. The clamping force thereby gradually increases. The slope of the part 15a becomes smaller with increase in the clamping force and the cam 15 can be thereby driven by a constant force. The clamping force reaches the defined force when the contacted part becomes to the part 15c.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a mold clamping device for a molding machine used in the production of plastics and die casting.

BACKGROUND OF THE INVENTION In recent years, mold clamping devices for molding machines have been required to be compact and consume less energy due to rising space requirements and energy costs.

An example of a conventional mold clamping device for a molding machine will be described below with reference to the drawings. In Figure 6, 1 is a guide, 2
is a fixed plate. Reference numeral 3 denotes a movable plate, which moves linearly toward or away from the fixed plate 2. 4 is a frame, 5 is a toggle mechanism with two arms, movable plate 3 and frame 4
is established between. 6 is a hydraulic or pneumatic cylinder that drives the toggle mechanism 6. 7 is the Ichihi type, and 8 is the lower type.

To explain the operation of the mold clamping device of the molding machine configured as above, first, the toggle mechanism 6 is extended by the oil U1 or the pneumatic glue nodder 6, and the movable platen 3 guided by the guide 1 is raised. The lower mold 8 is in contact with the upper mold 7. Furthermore, as the toggle mechanism 6 is extended, the mold clamping system constituted by the frame 4, the toggle mechanism 5, etc. is slightly deformed, and a predetermined mold clamping force is generated. Next, the toggle mechanism 5 is bent by the hydraulic or pneumatic cylinder 6, thereby eliminating deformation of the mold clamping system and releasing high pressure mold clamping. Furthermore, since the toggle mechanism 6 is bent, the lower die 8 has the above problem.

(1) When the included angle between the two arms of the toggle mechanism 6 becomes smaller, the force for raising or lowering the movable platen 3 decreases rapidly. Therefore, since the included angle cannot be reduced beyond a certain level, the mold clamping part becomes bulky. .

(→ Due to the bending of the shaft that makes up the toggle mechanism 6 and the deformation of the bearing surface, the rigidity of the mold clamping system of the molding machine, including the frame 4 and toggle mechanism 5, decreases, so a large force is required to drive the toggle mechanism 6. It becomes necessary.

(3) Since the mold opening/closing stroke and the high-pressure mold clamping stroke, which originally have different loads, are driven by a single hydraulic or pneumatic cylinder 6, energy consumption is large.

Next, another example of a conventional mold clamping device for a molding machine will be described. FIG. 6 shows a mold clamping device of a molding machine disclosed in Japanese Utility Model Application No. 66-102023. In FIG. 6, 101 is a mold, 102 is a power block that is connected to the mold 101 and moves linearly, and 103 is a power block 102.
A slide block 104 is a hydraulic cylinder that drives a slide block 103 that reciprocates in a straight line orthogonal to the direction of movement of the power block 102 .

To explain the operation of the molding machine configured as above, first, the mold 101 is closed, and then the slide block 1
03 is pulled in the incoming direction by the hydraulic cylinder 104. The inclined surface of the slide block 103 and the inclined surface of the power block come into contact, and the mold clamping system is slightly deformed, generating mold force.

However, in such a conventional configuration, the hydraulic cylinder 104 is configured to combine the molecules of the mold clamping force, which increase in proportion to the increase in the mold clamping force, and the frictional force between the power block 102 and the slide block 103. It was necessary to generate a force greater than the resultant force, whereas in the early stages of the mold clamping process, only a small force was required, resulting in a large loss of energy.

The present invention solves these problems, and aims to provide a mold clamping device for a molding machine that has a small mold clamping part, can obtain a predetermined mold clamping force with a small driving force, and consumes less energy. That is.

Means for Solving the Problem In order to solve this problem, the present invention includes a fixed plate, and a fixed plate that is provided opposite to the fixed plate and guided to move linearly toward or away from any fixed plate. a movable platen, a means for driving the movable platen, a contact portion supported by the movable platen, a contact portion supported by a frame and in contact with the abutment portion, the slope of the displacement curve of which is initially large when the mold is clamped; It is equipped with a cam that becomes smaller as the stroke progresses, and means for driving the cam.

Effect 6: With this configuration, an appropriate means for driving the movable platen can be selected regardless of high-pressure mold clamping, so the mold clamping part can be made smaller. Furthermore, since a highly rigid cam can be easily manufactured, the rigidity of the mold clamping system of the molding machine can be increased. In addition, the opening/closing process and high-pressure mold clamping process of the mold, which inherently have different loads,
It is possible to select an appropriate means for driving the movable platen and a means for driving the cam, and also to adjust the cam displacement curve appropriately in response to load fluctuations during the high-pressure mold clamping process and fluctuations in the output of the means for driving the cam. Therefore, energy loss can be reduced.

Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings.

First, a first embodiment will be explained based on FIG. 1. In the figure, 9 is a frame, 10 is a fixed plate fixed to the frame 9, 11 is a guide, 12 is a movable plate that moves up and down to approach or move away from the fixed plate 10 guided by the guide 11, and 13 is a movable plate. For example, an air cylinder is used as a means for driving 12, and 14 is a roller follower, for example, as a contact part attached to the movable platen 12.
6 is a cam, 16 is a roller supported by the frame 9 so as to be in contact with the lower surface of the cam 16, 17 is, for example, an air cylinder as a means for driving the cam 16, and 18 is a fixed side provided in several cases on the fixed platen 10. A mold, 19 is a movable side mold attached to the movable platen 12, and 2o is an injection nozzle.

Regarding the mold clamping device of the molding machine configured as shown below,
The operation will be explained below. First, the movable plate 12 is the guide 11
Guided by the air cylinder 13, the movable mold 19 is raised until it comes into contact with the fixed mold 18. Next, the cam 16 is pushed out by the air cylinder 17, the roller follower 14 is pushed up, the mold clamping system constituted by the frame 9, the cam 16, etc. is slightly deformed, and a predetermined mold clamping force is generated. In this state, melted resin or metal is injected from the injection nozzle 2o into the space formed by the stationary mold 18 and the movable mold 19, and is molded.

By pulling back the cam 16 by the air cylinder 17, the mold clamping system is no longer deformed and the high pressure mold clamping is released. Next, the movable platen 12 is lowered by the air cylinder 13, and the mold is opened.

The force difference 16 includes a portion whose displacement curve is expressed by equation (1).

However, 2: Displacement of the cam F: Force that drives the cam: Spring constant of the mold clamping system A: Constant , Part 15a is (1)
The displacement curve expressed by the formula, 15b part is (2) formula, 15c
The part has the form (→).

Z = a x + b ・・・・・・・・・
・・・・・・・・・・・・(2) Z=d
・・・・・・・・・・・・・・・・・・・・・(3)
However, a, b, and d are constants.

Formula (1) is expressed by the air cylinder 1709 in this embodiment.
Assuming that the bench force is constant and the friction between the roller follower 14 and the roller 16 cannot be ignored, the relationship between the displacement of the cam and the stroke is shown with F as a constant and A as a constant (4
) is obtained by solving the equation.

(→The expression is variable-separable, so 1-dz=cix -A z −dz =: dx -AZ Integrate this by the way If F=gz+Blogl--Azl, then 10 units/ " Because it is 1-AZ Solving 1--AB=.

k Therefore, if the coordinates are taken so that the equation ((f) becomes 2-0 at X-o, then 11 8-7 Substituting equation (7) into equation (6), that is, if the frictional force cannot be ignored, then The cam displacement curve of equation (8) may be used.

Cam 15 and roller follower 1 when mold clamping force is generated
4 will be explained in detail. First, the cam 16 starts contacting the roller follower 14 at the portion 16b. With the extrusion stroke of the air cylinder 17, the contact point moves to the portion 15a, and the mold clamping force gradually increases. 16a
Since the slope of the cam 16 in the section becomes gentler as X increases, that is, as the mold clamping force increases, the cam 15 can be driven with a constant force. The contact point reaches a predetermined mold clamping force at the portion 16c.

As described above, according to this embodiment, there is a fixed plate 10 fixed to the frame 9, and a fixed plate 10 that is provided opposite to the fixed plate 10 and guided to move linearly toward or away from the fixed plate 10. The movable platen 12 that is
An air cylinder 13 that drives the frame 9 contacts the movable platen 12 via a roller follower 14 and
The cam 16 is supported by a cam 16 whose displacement curve includes equation (2).
By providing an air cylinder 17 for driving this cam 15, the height of the mold clamping portion can be reduced, and the entire device can be made smaller. In addition, since the rigidity of the mold clamping system can be increased, a predetermined mold clamping force can be obtained with a small driving force, and the energy consumption required for mold clamping can be reduced by using the displacement curve of the cam 15 that corresponds to changes in mold clamping force. It can be reduced.

FIG. 3 shows the main parts of the mold clamping device of the molding machine in the second embodiment. In the figure, 21 is a movable plate, 22 is a roller follower, 23 is a frame, 24 is a cam having a shape in which the cam shown in FIG. The configuration is approximately the same as that shown in FIG. The structure differs from that shown in FIG. 13 in that the cam 24 is directly supported by the frame 23, and that a geared motor 26 and a chain 26 are provided as means for driving the cam 24.

The operation of the second embodiment configured as above will be explained. First, after the movable platen 21 is raised, the cam 24 is rotated by the geared motor 26, and the roller follower 2
2 is pushed up, the mold clamping system is slightly deformed, and a predetermined mold clamping force is generated. The mold clamping is released by rotating the geared motor 26 in the reverse direction. As described above, the cam 24 is directly supported by the frame 23 without using rollers, and the cam 2
By providing a geared motor 26 that drives 4 and a chain 26, the number of line contact points can be reduced, making it possible to increase the rigidity of the mold clamping system and obtain a predetermined mold clamping force with a smaller driving force. Can be done.

In the first embodiment, the frame 9 has a C-shaped structure and is vertical, but it may also be a frame composed of a plurality of tights (-) and a fixed support member, or it may be horizontal.

14 b.

In the first and second embodiments, the roller follower 14 or 22 was used as the member that comes into contact with the cam 16 or 24, respectively, but as shown in FIG. 4, a convex sliding member was used. You can also use it as

Effects of the Invention As described above, according to the present invention, the means for driving the movable platen, the rolling element supported by the movable platen, the means for driving the movable platen, the rolling element supported by the frame and in contact with the rolling element, and the gradient of the displacement curve thereof is initially large. By providing a cam that becomes smaller as the mold clamping stroke progresses and a means to drive this cam, the mold clamping part can be made smaller, a predetermined mold clamping force can be obtained with a small driving force, and the energy consumption required for mold clamping can be reduced. It can be reduced.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a mold clamping device of a molding machine showing a first embodiment of the present invention, FIG. 2 is an enlarged front view of the main part of the cam shown in FIG. 1,
FIG. 3 is a sectional view of essential parts of a mold clamping device of a molding machine showing a second embodiment of the present invention, FIG. 4 is an enlarged front view of a cam section in another embodiment of the present invention, and FIG. 6 is a conventional A sectional view of the mold clamping device of the molding machine, FIG. 6, 168. is a sectional view of a mold clamping device of another conventional molding machine. 9...Frame, 10...Fixed plate, 1
1...Guide, 12...Movable plate, 13
...Air cylinder, 14...Roller follower +7-. 15...cam, 16...
...Low 7-. 17...Air cylinder,
18... Fixed side mold, 19... Movable side mold, 21... Movable platen, 22... Roller follower, 23...・Frame, 24...
...Cam, 26... Geared motor. Name of agent: Patent attorney Toshio Nakao and one other person Q-
--F L-Mui 0---11i] Lending 5 Guhi) Eeeee Power゛Ik f2--Ichitsuji Single Ka 4 draw 15--Ichikumzogo 5 Fig. Unexamined Japanese Patent Publication []HG3-11323<6) Figure 6

Claims (1)

[Scope of Claims] A fixed platen, a movable platen arranged opposite to the fixed platen and guided to move linearly toward or away from the fixed platen, and means for driving the movable platen. , a contact part supported by the movable platen, a cam supported by the frame and in contact with the contact part, the gradient of whose displacement curve is initially large and becomes smaller as the mold clamping stroke progresses, and means for driving the cam. and the displacement curve of the cam is given by the following formula - (1/A)Z - (F/A^2K)log | (F/K)
-AZ|=X+C However, Z: Displacement of the cam F: Force that drives the cam K: Spring constant of the mold clamping system A: Constant mold clamping device.